用 Jetpack Compose 构建一个产品管理安卓应用

本教程演示了如何构建一个基本的产品管理应用。该应用展示了管理操作、照片上传、账户创建和身份验证，使用的技术有：

🌐 This tutorial demonstrates how to build a basic product management app. The app demonstrates management operations, photo upload, account creation and authentication using:

Supabase 数据库 - 一个用于存储用户数据的 Postgres 数据库，并且有行级安全，所以数据是受保护的，用户只能访问自己的信息。
Supabase Auth - 用户通过发送到他们邮箱的魔法链接登录（无需设置密码）。
Supabase Storage - 用户可以上传个人头像。

manage-product-cover

如果你在使用本指南的过程中遇到困难，可以参考 GitHub 上的完整示例。

🌐 If you get stuck while working through this guide, refer to the full example on GitHub.

项目设置 #

🌐 Project setup

在构建之前，你必须在 Supabase 中为一个新项目设置好数据库和 API，然后在数据库里创建一个“schema”。

🌐 Before building, you must set up your Database and API with a new Project in Supabase and then create a "schema" inside the database.

创建一个项目 #

🌐 Create a project

在 Supabase 仪表板中创建一个新项目。
输入你的项目详情。
等新数据库上线。

设置数据库模式 #

🌐 Set up the database schema

现在我们要设置数据库模式了。你可以从下面复制/粘贴 SQL 并自己运行。

🌐 Now we are going to set up the database schema. You can copy/paste the SQL from below and run it yourself.

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-- Create a table for public profiles
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create table
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  public.products (
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    id uuid not null default gen_random_uuid (),
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    name text not null,
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    price real not null,
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    image text null,
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    constraint products_pkey primary key (id)
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  ) tablespace pg_default;
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-- Set up Storage!
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insert into storage.buckets (id, name)
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  values ('Product Image', 'Product Image');
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-- Set up access controls for storage.
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-- See https://supabase.com/docs/guides/storage/security/access-control#policy-examples for more details.
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CREATE POLICY "Enable read access for all users" ON "storage"."objects"
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AS PERMISSIVE FOR SELECT
20
TO public
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USING (true)
22
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CREATE POLICY "Enable insert for all users" ON "storage"."objects"
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AS PERMISSIVE FOR INSERT
25
TO authenticated, anon
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WITH CHECK (true)
27
28
CREATE POLICY "Enable update for all users" ON "storage"."objects"
29
AS PERMISSIVE FOR UPDATE
30
TO public
31
USING (true)
32
WITH CHECK (true)

获取 API 详情 #

🌐 Get API details

要与数据库表中的数据进行交互，你可以使用封装了自动生成的数据 API 端点的客户端库，并使用来自项目 Connect 对话框的项目 URL 和密钥进行认证。

🌐 To interact with data in database tables, you use the client libraries that wrap the auto-generated Data API endpoints, authenticating using the Project URL and key from the project Connect dialog.

Project URL

Publishable key

阅读 API 密钥文档以全面了解所有密钥类型、用途以及在哪里可以找到它们。

设置谷歌认证 #

🌐 Set up Google authentication

从 Google 控制台创建一个新项目并添加 OAuth2 凭证。

🌐 From the Google Console, create a new project and add OAuth2 credentials.

Create Google OAuth credentials

在你的 Supabase 认证设置中启用 Google 作为提供商，并按照认证文档中的说明设置所需的凭据。

🌐 In your Supabase Auth settings enable Google as a provider and set the required credentials as outlined in the auth docs.

正在构建应用 #

🌐 Building the app

创建新的安卓项目 #

🌐 Create new Android project

打开 Android Studio > 新建项目 > 基础活动（Jetpack Compose）。

🌐 Open Android Studio > New Project > Base Activity (Jetpack Compose).

Android Studio new project

安全地设置 API 密钥和密钥密码 #

🌐 Set up API key and secret securely

创建本地环境密钥 #

🌐 Create local environment secret

在你项目的根目录（与 build.gradle 同级）创建或编辑 local.properties 文件。

🌐 Create or edit the local.properties file at the root (same level as build.gradle) of your project.

注意：不要将此文件提交到你的源代码管理，例如，不要将其添加到你的 .gitignore 文件中！

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SUPABASE_PUBLISHABLE_KEY=YOUR_SUPABASE_PUBLISHABLE_KEY
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SUPABASE_URL=YOUR_SUPABASE_URL

读取并设置 `BuildConfig`#

🌐 Read and set value to BuildConfig

在你的 build.gradle（应用）文件中，创建一个 Properties 对象，并通过调用 buildConfigField 方法从你的 local.properties 文件中读取值：

🌐 In your build.gradle (app) file, create a Properties object and read the values from your local.properties file by calling the buildConfigField method:

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defaultConfig {
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   applicationId "com.example.manageproducts"
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   minSdkVersion 22
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   targetSdkVersion 33
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   versionCode 5
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   versionName "1.0"
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   testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
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   // Set value part
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   Properties properties = new Properties()
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   properties.load(project.rootProject.file("local.properties").newDataInputStream())
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   buildConfigField("String", "SUPABASE_PUBLISHABLE_KEY", "\"${properties.getProperty("SUPABASE_PUBLISHABLE_KEY")}\"")
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   buildConfigField("String", "SECRET", "\"${properties.getProperty("SECRET")}\"")
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   buildConfigField("String", "SUPABASE_URL", "\"${properties.getProperty("SUPABASE_URL")}\"")
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}

使用 `BuildConfig`#

🌐 Use value from BuildConfig

从 BuildConfig 读取值：

🌐 Read the value from BuildConfig:

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val url = BuildConfig.SUPABASE_URL
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val apiKey = BuildConfig.SUPABASE_PUBLISHABLE_KEY

设置 Supabase 依赖 #

🌐 Set up Supabase dependencies

Gradle dependencies

在 build.gradle（应用）文件中，添加这些依赖，然后点击“立即同步”。将依赖版本占位符 $supabase_version 和 $ktor_version 替换为各自的最新版本。

🌐 In the build.gradle (app) file, add these dependencies then press "Sync now." Replace the dependency version placeholders $supabase_version and $ktor_version with their respective latest versions.

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implementation "io.github.jan-tennert.supabase:postgrest-kt:$supabase_version"
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implementation "io.github.jan-tennert.supabase:storage-kt:$supabase_version"
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implementation "io.github.jan-tennert.supabase:auth-kt:$supabase_version"
4
implementation "io.ktor:ktor-client-android:$ktor_version"
5
implementation "io.ktor:ktor-client-core:$ktor_version"
6
implementation "io.ktor:ktor-utils:$ktor_version"

同样在 build.gradle（app）文件中，添加用于序列化的插件。这个插件的版本应该和你的 Kotlin 版本一样。

🌐 Also in the build.gradle (app) file, add the plugin for serialization. The version of this plugin should be the same as your Kotlin version.

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plugins {
2
    ...
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    id 'org.jetbrains.kotlin.plugin.serialization' version '$kotlin_version'
4
    ...
5
}

为依赖注入设置 Hilt #

🌐 Set up Hilt for dependency injection

在 build.gradle（应用）文件中，添加以下内容：

🌐 In the build.gradle (app) file, add the following:

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implementation "com.google.dagger:hilt-android:$hilt_version"
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annotationProcessor "com.google.dagger:hilt-compiler:$hilt_version"
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implementation("androidx.hilt:hilt-navigation-compose:1.0.0")

创建一个带有 @HiltAndroidApp 注解的、继承自 Application 的新 ManageProductApplication.kt 类：

🌐 Create a new ManageProductApplication.kt class extending Application with @HiltAndroidApp annotation:

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// ManageProductApplication.kt
2
@HiltAndroidApp
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class ManageProductApplication: Application()

打开 AndroidManifest.xml 文件，更新 Application 标签的 name 属性：

🌐 Open the AndroidManifest.xml file, update name property of Application tag:

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<application
2
...
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    android:name=".ManageProductApplication"
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...
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</application>

创建 MainActivity：

🌐 Create the MainActivity:

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@AndroidEntryPoint
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class MainActivity : ComponentActivity() {
3
    //This will come later
4
}

用 Hilt 提供 Supabase 实例 #

🌐 Provide Supabase instances with Hilt

为了让这个应用更容易测试，创建一个 SupabaseModule.kt 文件，如下所示：

🌐 To make the app easier to test, create a SupabaseModule.kt file as follows:

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@InstallIn(SingletonComponent::class)
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@Module
3
object SupabaseModule {
4
5
    @Provides
6
    @Singleton
7
    fun provideSupabaseClient(): SupabaseClient {
8
        return createSupabaseClient(
9
            supabaseUrl = BuildConfig.SUPABASE_URL,
10
            supabaseKey = BuildConfig.SUPABASE_PUBLISHABLE_KEY
11
        ) {
12
            install(Postgrest)
13
            install(Auth) {
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                flowType = FlowType.PKCE
15
                scheme = "app"
16
                host = "supabase.com"
17
            }
18
            install(Storage)
19
        }
20
    }
21
22
    @Provides
23
    @Singleton
24
    fun provideSupabaseDatabase(client: SupabaseClient): Postgrest {
25
        return client.postgrest
26
    }
27
28
    @Provides
29
    @Singleton
30
    fun provideSupabaseAuth(client: SupabaseClient): Auth {
31
        return client.auth
32
    }
33
34
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    @Provides
36
    @Singleton
37
    fun provideSupabaseStorage(client: SupabaseClient): Storage {
38
        return client.storage
39
    }
40
41
}

创建一个数据传输对象 #

🌐 Create a data transfer object

创建一个 ProductDto.kt 类，并使用注解从 Supabase 解析数据：

🌐 Create a ProductDto.kt class and use annotations to parse data from Supabase:

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@Serializable
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data class ProductDto(
3
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    @SerialName("name")
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    val name: String,
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    @SerialName("price")
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    val price: Double,
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    @SerialName("image")
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    val image: String?,
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    @SerialName("id")
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    val id: String,
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)

在 Product.kt 中创建一个域对象，在你的视图中展示数据：

🌐 Create a Domain object in Product.kt expose the data in your view:

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data class Product(
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    val id: String,
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    val name: String,
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    val price: Double,
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    val image: String?
6
)

实现仓库 #

🌐 Implement repositories

创建一个 ProductRepository 接口及其实现，命名为 ProductRepositoryImpl。它包含与 Supabase 数据源交互的逻辑。对 AuthenticationRepository 也做同样的处理。

🌐 Create a ProductRepository interface and its implementation named ProductRepositoryImpl. This holds the logic to interact with data sources from Supabase. Do the same with the AuthenticationRepository.

创建产品仓库：

🌐 Create the Product Repository:

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interface ProductRepository {
2
    suspend fun createProduct(product: Product): Boolean
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    suspend fun getProducts(): List<ProductDto>?
4
    suspend fun getProduct(id: String): ProductDto
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    suspend fun deleteProduct(id: String)
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    suspend fun updateProduct(
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        id: String, name: String, price: Double, imageName: String, imageFile: ByteArray
8
    )
9
}

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class ProductRepositoryImpl @Inject constructor(
2
    private val postgrest: Postgrest,
3
    private val storage: Storage,
4
) : ProductRepository {
5
    override suspend fun createProduct(product: Product): Boolean {
6
        return try {
7
            withContext(Dispatchers.IO) {
8
                val productDto = ProductDto(
9
                    name = product.name,
10
                    price = product.price,
11
                )
12
                postgrest.from("products").insert(productDto)
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                true
14
            }
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            true
16
        } catch (e: java.lang.Exception) {
17
            throw e
18
        }
19
    }
20
21
    override suspend fun getProducts(): List<ProductDto>? {
22
        return withContext(Dispatchers.IO) {
23
            val result = postgrest.from("products")
24
                .select().decodeList<ProductDto>()
25
            result
26
        }
27
    }
28
29
30
    override suspend fun getProduct(id: String): ProductDto {
31
        return withContext(Dispatchers.IO) {
32
            postgrest.from("products").select {
33
                filter {
34
                    eq("id", id)
35
                }
36
            }.decodeSingle<ProductDto>()
37
        }
38
    }
39
40
    override suspend fun deleteProduct(id: String) {
41
        return withContext(Dispatchers.IO) {
42
            postgrest.from("products").delete {
43
                filter {
44
                    eq("id", id)
45
                }
46
            }
47
        }
48
    }
49
50
    override suspend fun updateProduct(
51
        id: String,
52
        name: String,
53
        price: Double,
54
        imageName: String,
55
        imageFile: ByteArray
56
    ) {
57
        withContext(Dispatchers.IO) {
58
            if (imageFile.isNotEmpty()) {
59
                val imageUrl =
60
                    storage.from("Product%20Image").upload(
61
                        path = "$imageName.png",
62
                        data = imageFile,
63
                        upsert = true
64
                    )
65
                postgrest.from("products").update({
66
                    set("name", name)
67
                    set("price", price)
68
                    set("image", buildImageUrl(imageFileName = imageUrl))
69
                }) {
70
                    filter {
71
                        eq("id", id)
72
                    }
73
                }
74
            } else {
75
                postgrest.from("products").update({
76
                    set("name", name)
77
                    set("price", price)
78
                }) {
79
                    filter {
80
                        eq("id", id)
81
                    }
82
                }
83
            }
84
        }
85
    }
86
87
    // Because I named the bucket as "Product Image" so when it turns to an url, it is "%20"
88
    // For better approach, you should create your bucket name without space symbol
89
    private fun buildImageUrl(imageFileName: String) =
90
        "${BuildConfig.SUPABASE_URL}/storage/v1/object/public/${imageFileName}".replace(" ", "%20")
91
}

创建认证仓库：

🌐 Create the Authentication Repository:

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interface AuthenticationRepository {
2
    suspend fun signIn(email: String, password: String): Boolean
3
    suspend fun signUp(email: String, password: String): Boolean
4
    suspend fun signInWithGoogle(): Boolean
5
}

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class AuthenticationRepositoryImpl @Inject constructor(
2
    private val auth: Auth
3
) : AuthenticationRepository {
4
    override suspend fun signIn(email: String, password: String): Boolean {
5
        return try {
6
            auth.signInWith(Email) {
7
                this.email = email
8
                this.password = password
9
            }
10
            true
11
        } catch (e: Exception) {
12
            false
13
        }
14
    }
15
16
    override suspend fun signUp(email: String, password: String): Boolean {
17
        return try {
18
            auth.signUpWith(Email) {
19
                this.email = email
20
                this.password = password
21
            }
22
            true
23
        } catch (e: Exception) {
24
            false
25
        }
26
    }
27
28
    override suspend fun signInWithGoogle(): Boolean {
29
        return try {
30
            auth.signInWith(Google)
31
            true
32
        } catch (e: Exception) {
33
            false
34
        }
35
    }
36
}

实现屏幕 #

🌐 Implement screens

要导航屏幕，请使用 AndroidX 导航库。对于路由，请实现 Destination 接口：

🌐 To navigate screens, use the AndroidX navigation library. For routes, implement a Destination interface:

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interface Destination {
2
    val route: String
3
    val title: String
4
}
5
6
7
object ProductListDestination : Destination {
8
    override val route = "product_list"
9
    override val title = "Product List"
10
}
11
12
object ProductDetailsDestination : Destination {
13
    override val route = "product_details"
14
    override val title = "Product Details"
15
    const val productId = "product_id"
16
    val arguments = listOf(navArgument(name = productId) {
17
        type = NavType.StringType
18
    })
19
    fun createRouteWithParam(productId: String) = "$route/${productId}"
20
}
21
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object AddProductDestination : Destination {
23
    override val route = "add_product"
24
    override val title = "Add Product"
25
}
26
27
object AuthenticationDestination: Destination {
28
    override val route = "authentication"
29
    override val title = "Authentication"
30
}
31
32
object SignUpDestination: Destination {
33
    override val route = "signup"
34
    override val title = "Sign Up"
35
}

这以后在不同屏幕之间切换会很有帮助。

🌐 This will help later for navigating between screens.

创建一个 ProductListViewModel：

🌐 Create a ProductListViewModel:

1
@HiltViewModel
2
class ProductListViewModel @Inject constructor(
3
private val productRepository: ProductRepository,
4
) : ViewModel() {
5
6
    private val _productList = MutableStateFlow<List<Product>?>(listOf())
7
    val productList: Flow<List<Product>?> = _productList
8
9
10
    private val _isLoading = MutableStateFlow(false)
11
    val isLoading: Flow<Boolean> = _isLoading
12
13
    init {
14
        getProducts()
15
    }
16
17
    fun getProducts() {
18
        viewModelScope.launch {
19
            val products = productRepository.getProducts()
20
            _productList.emit(products?.map { it -> it.asDomainModel() })
21
        }
22
    }
23
24
    fun removeItem(product: Product) {
25
        viewModelScope.launch {
26
            val newList = mutableListOf<Product>().apply { _productList.value?.let { addAll(it) } }
27
            newList.remove(product)
28
            _productList.emit(newList.toList())
29
            // Call api to remove
30
            productRepository.deleteProduct(id = product.id)
31
            // Then fetch again
32
            getProducts()
33
        }
34
    }
35
36
    private fun ProductDto.asDomainModel(): Product {
37
        return Product(
38
            id = this.id,
39
            name = this.name,
40
            price = this.price,
41
            image = this.image
42
        )
43
    }
44
45
}

创建 ProductListScreen.kt：

🌐 Create the ProductListScreen.kt:

1
@OptIn(ExperimentalMaterial3Api::class, ExperimentalMaterialApi::class)
2
@Composable
3
fun ProductListScreen(
4
    modifier: Modifier = Modifier,
5
    navController: NavController,
6
    viewModel: ProductListViewModel = hiltViewModel(),
7
) {
8
    val isLoading by viewModel.isLoading.collectAsState(initial = false)
9
    val swipeRefreshState = rememberSwipeRefreshState(isRefreshing = isLoading)
10
    SwipeRefresh(state = swipeRefreshState, onRefresh = { viewModel.getProducts() }) {
11
        Scaffold(
12
            topBar = {
13
                TopAppBar(
14
                    backgroundColor = MaterialTheme.colorScheme.primary,
15
                    title = {
16
                        Text(
17
                            text = stringResource(R.string.product_list_text_screen_title),
18
                            color = MaterialTheme.colorScheme.onPrimary,
19
                        )
20
                    },
21
                )
22
            },
23
            floatingActionButton = {
24
                AddProductButton(onClick = { navController.navigate(AddProductDestination.route) })
25
            }
26
        ) { padding ->
27
            val productList = viewModel.productList.collectAsState(initial = listOf()).value
28
            if (!productList.isNullOrEmpty()) {
29
                LazyColumn(
30
                    modifier = modifier.padding(padding),
31
                    contentPadding = PaddingValues(5.dp)
32
                ) {
33
                    itemsIndexed(
34
                        items = productList,
35
                        key = { _, product -> product.name }) { _, item ->
36
                        val state = rememberDismissState(
37
                            confirmStateChange = {
38
                                if (it == DismissValue.DismissedToStart) {
39
                                    // Handle item removed
40
                                    viewModel.removeItem(item)
41
                                }
42
                                true
43
                            }
44
                        )
45
                        SwipeToDismiss(
46
                            state = state,
47
                            background = {
48
                                val color by animateColorAsState(
49
                                    targetValue = when (state.dismissDirection) {
50
                                        DismissDirection.StartToEnd -> MaterialTheme.colorScheme.primary
51
                                        DismissDirection.EndToStart -> MaterialTheme.colorScheme.primary.copy(
52
                                            alpha = 0.2f
53
                                        )
54
                                        null -> Color.Transparent
55
                                    }
56
                                )
57
                                Box(
58
                                    modifier = modifier
59
                                        .fillMaxSize()
60
                                        .background(color = color)
61
                                        .padding(16.dp),
62
                                ) {
63
                                    Icon(
64
                                        imageVector = Icons.Filled.Delete,
65
                                        contentDescription = null,
66
                                        tint = MaterialTheme.colorScheme.primary,
67
                                        modifier = modifier.align(Alignment.CenterEnd)
68
                                    )
69
                                }
70
71
                            },
72
                            dismissContent = {
73
                                ProductListItem(
74
                                    product = item,
75
                                    modifier = modifier,
76
                                    onClick = {
77
                                        navController.navigate(
78
                                            ProductDetailsDestination.createRouteWithParam(
79
                                                item.id
80
                                            )
81
                                        )
82
                                    },
83
                                )
84
                            },
85
                            directions = setOf(DismissDirection.EndToStart),
86
                        )
87
                    }
88
                }
89
            } else {
90
                Text("Product list is empty!")
91
            }
92
93
        }
94
    }
95
}
96
97
@Composable
98
private fun AddProductButton(
99
    modifier: Modifier = Modifier,
100
    onClick: () -> Unit,
101
) {
102
    FloatingActionButton(
103
        modifier = modifier,
104
        onClick = onClick,
105
        containerColor = MaterialTheme.colorScheme.primary,
106
        contentColor = MaterialTheme.colorScheme.onPrimary
107
    ) {
108
        Icon(
109
            imageVector = Icons.Filled.Add,
110
            contentDescription = null,
111
        )
112
    }
113
}

创建 ProductDetailsViewModel.kt：

🌐 Create the ProductDetailsViewModel.kt:

1
@HiltViewModel
2
class ProductDetailsViewModel @Inject constructor(
3
    private val productRepository: ProductRepository,
4
    savedStateHandle: SavedStateHandle,
5
    ) : ViewModel() {
6
7
    private val _product = MutableStateFlow<Product?>(null)
8
    val product: Flow<Product?> = _product
9
10
    private val _name = MutableStateFlow("")
11
    val name: Flow<String> = _name
12
13
    private val _price = MutableStateFlow(0.0)
14
    val price: Flow<Double> = _price
15
16
    private val _imageUrl = MutableStateFlow("")
17
    val imageUrl: Flow<String> = _imageUrl
18
19
    init {
20
        val productId = savedStateHandle.get<String>(ProductDetailsDestination.productId)
21
        productId?.let {
22
            getProduct(productId = it)
23
        }
24
    }
25
26
    private fun getProduct(productId: String) {
27
        viewModelScope.launch {
28
           val result = productRepository.getProduct(productId).asDomainModel()
29
            _product.emit(result)
30
            _name.emit(result.name)
31
            _price.emit(result.price)
32
        }
33
    }
34
35
    fun onNameChange(name: String) {
36
        _name.value = name
37
    }
38
39
    fun onPriceChange(price: Double) {
40
        _price.value = price
41
    }
42
43
    fun onSaveProduct(image: ByteArray) {
44
        viewModelScope.launch {
45
            productRepository.updateProduct(
46
                id = _product.value?.id,
47
                price = _price.value,
48
                name = _name.value,
49
                imageFile = image,
50
                imageName = "image_${_product.value.id}",
51
            )
52
        }
53
    }
54
55
    fun onImageChange(url: String) {
56
        _imageUrl.value = url
57
    }
58
59
    private fun ProductDto.asDomainModel(): Product {
60
        return Product(
61
            id = this.id,
62
            name = this.name,
63
            price = this.price,
64
            image = this.image
65
        )
66
    }
67
}

创建 ProductDetailsScreen.kt：

🌐 Create the ProductDetailsScreen.kt:

1
@OptIn(ExperimentalCoilApi::class)
2
@SuppressLint("UnusedMaterialScaffoldPaddingParameter")
3
@Composable
4
fun ProductDetailsScreen(
5
    modifier: Modifier = Modifier,
6
    viewModel: ProductDetailsViewModel = hiltViewModel(),
7
    navController: NavController,
8
    productId: String?,
9
) {
10
    val snackBarHostState = remember { SnackbarHostState() }
11
    val coroutineScope = rememberCoroutineScope()
12
13
    Scaffold(
14
        snackbarHost = { SnackbarHost(snackBarHostState) },
15
        topBar = {
16
            TopAppBar(
17
                navigationIcon = {
18
                    IconButton(onClick = {
19
                        navController.navigateUp()
20
                    }) {
21
                        Icon(
22
                            imageVector = Icons.Filled.ArrowBack,
23
                            contentDescription = null,
24
                            tint = MaterialTheme.colorScheme.onPrimary
25
                        )
26
                    }
27
                },
28
                backgroundColor = MaterialTheme.colorScheme.primary,
29
                title = {
30
                    Text(
31
                        text = stringResource(R.string.product_details_text_screen_title),
32
                        color = MaterialTheme.colorScheme.onPrimary,
33
                    )
34
                },
35
            )
36
        }
37
    ) {
38
        val name = viewModel.name.collectAsState(initial = "")
39
        val price = viewModel.price.collectAsState(initial = 0.0)
40
        var imageUrl = Uri.parse(viewModel.imageUrl.collectAsState(initial = null).value)
41
        val contentResolver = LocalContext.current.contentResolver
42
43
        Column(
44
            modifier = modifier
45
                .padding(16.dp)
46
                .fillMaxSize()
47
        ) {
48
            val galleryLauncher =
49
                rememberLauncherForActivityResult(ActivityResultContracts.GetContent())
50
                { uri ->
51
                    uri?.let {
52
                        if (it.toString() != imageUrl.toString()) {
53
                            viewModel.onImageChange(it.toString())
54
                        }
55
                    }
56
                }
57
58
            Image(
59
                painter = rememberImagePainter(imageUrl),
60
                contentScale = ContentScale.Fit,
61
                contentDescription = null,
62
                modifier = Modifier
63
                    .padding(16.dp, 8.dp)
64
                    .size(100.dp)
65
                    .align(Alignment.CenterHorizontally)
66
            )
67
            IconButton(modifier = modifier.align(alignment = Alignment.CenterHorizontally),
68
                onClick = {
69
                    galleryLauncher.launch("image/*")
70
                }) {
71
                Icon(
72
                    imageVector = Icons.Filled.Edit,
73
                    contentDescription = null,
74
                    tint = MaterialTheme.colorScheme.primary
75
                )
76
            }
77
            OutlinedTextField(
78
                label = {
79
                    Text(
80
                        text = "Product name",
81
                        color = MaterialTheme.colorScheme.primary,
82
                        style = MaterialTheme.typography.titleMedium
83
                    )
84
                },
85
                maxLines = 2,
86
                shape = RoundedCornerShape(32),
87
                modifier = modifier.fillMaxWidth(),
88
                value = name.value,
89
                onValueChange = {
90
                    viewModel.onNameChange(it)
91
                },
92
            )
93
            Spacer(modifier = modifier.height(12.dp))
94
            OutlinedTextField(
95
                label = {
96
                    Text(
97
                        text = "Product price",
98
                        color = MaterialTheme.colorScheme.primary,
99
                        style = MaterialTheme.typography.titleMedium
100
                    )
101
                },
102
                maxLines = 2,
103
                shape = RoundedCornerShape(32),
104
                modifier = modifier.fillMaxWidth(),
105
                value = price.value.toString(),
106
                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
107
                onValueChange = {
108
                    viewModel.onPriceChange(it.toDouble())
109
                },
110
            )
111
            Spacer(modifier = modifier.weight(1f))
112
            Button(
113
                modifier = modifier.fillMaxWidth(),
114
                onClick = {
115
                    if (imageUrl.host?.contains("supabase") == true) {
116
                        viewModel.onSaveProduct(image = byteArrayOf())
117
                    } else {
118
                        val image = uriToByteArray(contentResolver, imageUrl)
119
                        viewModel.onSaveProduct(image = image)
120
                    }
121
                    coroutineScope.launch {
122
                        snackBarHostState.showSnackbar(
123
                            message = "Product updated successfully !",
124
                            duration = SnackbarDuration.Short
125
                        )
126
                    }
127
                }) {
128
                Text(text = "Save changes")
129
            }
130
            Spacer(modifier = modifier.height(12.dp))
131
            OutlinedButton(
132
                modifier = modifier
133
                    .fillMaxWidth(),
134
                onClick = {
135
                    navController.navigateUp()
136
                }) {
137
                Text(text = "Cancel")
138
            }
139
140
        }
141
142
    }
143
}
144
145
146
private fun getBytes(inputStream: InputStream): ByteArray {
147
    val byteBuffer = ByteArrayOutputStream()
148
    val bufferSize = 1024
149
    val buffer = ByteArray(bufferSize)
150
    var len = 0
151
    while (inputStream.read(buffer).also { len = it } != -1) {
152
        byteBuffer.write(buffer, 0, len)
153
    }
154
    return byteBuffer.toByteArray()
155
}
156
157
158
private fun uriToByteArray(contentResolver: ContentResolver, uri: Uri): ByteArray {
159
    if (uri == Uri.EMPTY) {
160
        return byteArrayOf()
161
    }
162
    val inputStream = contentResolver.openInputStream(uri)
163
    if (inputStream != null) {
164
        return getBytes(inputStream)
165
    }
166
    return byteArrayOf()
167
}

创建一个 AddProductScreen：

🌐 Create a AddProductScreen:

1
@SuppressLint("UnusedMaterial3ScaffoldPaddingParameter")
2
@OptIn(ExperimentalMaterial3Api::class)
3
@Composable
4
fun AddProductScreen(
5
    modifier: Modifier = Modifier,
6
    navController: NavController,
7
    viewModel: AddProductViewModel = hiltViewModel(),
8
) {
9
    Scaffold(
10
        topBar = {
11
            TopAppBar(
12
                navigationIcon = {
13
                    IconButton(onClick = {
14
                        navController.navigateUp()
15
                    }) {
16
                        Icon(
17
                            imageVector = Icons.Filled.ArrowBack,
18
                            contentDescription = null,
19
                            tint = MaterialTheme.colorScheme.onPrimary
20
                        )
21
                    }
22
                },
23
                backgroundColor = MaterialTheme.colorScheme.primary,
24
                title = {
25
                    Text(
26
                        text = stringResource(R.string.add_product_text_screen_title),
27
                        color = MaterialTheme.colorScheme.onPrimary,
28
                    )
29
                },
30
            )
31
        }
32
    ) { padding ->
33
        val navigateAddProductSuccess =
34
            viewModel.navigateAddProductSuccess.collectAsState(initial = null).value
35
        val isLoading =
36
            viewModel.isLoading.collectAsState(initial = null).value
37
        if (isLoading == true) {
38
            LoadingScreen(message = "Adding Product",
39
                onCancelSelected = {
40
                    navController.navigateUp()
41
                })
42
        } else {
43
            SuccessScreen(
44
                message = "Product added",
45
                onMoreAction = {
46
                    viewModel.onAddMoreProductSelected()
47
                },
48
                onNavigateBack = {
49
                    navController.navigateUp()
50
                })
51
        }
52
53
    }
54
}

创建 AddProductViewModel.kt：

🌐 Create the AddProductViewModel.kt:

1
@HiltViewModel
2
class AddProductViewModel @Inject constructor(
3
    private val productRepository: ProductRepository,
4
) : ViewModel() {
5
6
    private val _isLoading = MutableStateFlow(false)
7
    val isLoading: Flow<Boolean> = _isLoading
8
9
    private val _showSuccessMessage = MutableStateFlow(false)
10
    val showSuccessMessage: Flow<Boolean> = _showSuccessMessage
11
12
    fun onCreateProduct(name: String, price: Double) {
13
        if (name.isEmpty() || price <= 0) return
14
        viewModelScope.launch {
15
            _isLoading.value = true
16
            val product = Product(
17
                id = UUID.randomUUID().toString(),
18
                name = name,
19
                price = price,
20
            )
21
            productRepository.createProduct(product = product)
22
            _isLoading.value = false
23
            _showSuccessMessage.emit(true)
24
25
        }
26
    }
27
}

创建一个 SignUpViewModel：

🌐 Create a SignUpViewModel:

1
@HiltViewModel
2
class SignUpViewModel @Inject constructor(
3
    private val authenticationRepository: AuthenticationRepository
4
) : ViewModel() {
5
6
    private val _email = MutableStateFlow("")
7
    val email: Flow<String> = _email
8
9
    private val _password = MutableStateFlow("")
10
    val password = _password
11
12
    fun onEmailChange(email: String) {
13
        _email.value = email
14
    }
15
16
    fun onPasswordChange(password: String) {
17
        _password.value = password
18
    }
19
20
    fun onSignUp() {
21
        viewModelScope.launch {
22
            authenticationRepository.signUp(
23
                email = _email.value,
24
                password = _password.value
25
            )
26
        }
27
    }
28
}

创建 SignUpScreen.kt：

🌐 Create the SignUpScreen.kt:

1
@Composable
2
fun SignUpScreen(
3
    modifier: Modifier = Modifier,
4
    navController: NavController,
5
    viewModel: SignUpViewModel = hiltViewModel()
6
) {
7
    val snackBarHostState = remember { SnackbarHostState() }
8
    val coroutineScope = rememberCoroutineScope()
9
    Scaffold(
10
        snackbarHost = { androidx.compose.material.SnackbarHost(snackBarHostState) },
11
        topBar = {
12
            TopAppBar(
13
                navigationIcon = {
14
                    IconButton(onClick = {
15
                        navController.navigateUp()
16
                    }) {
17
                        Icon(
18
                            imageVector = Icons.Filled.ArrowBack,
19
                            contentDescription = null,
20
                            tint = MaterialTheme.colorScheme.onPrimary
21
                        )
22
                    }
23
                },
24
                backgroundColor = MaterialTheme.colorScheme.primary,
25
                title = {
26
                    Text(
27
                        text = "Sign Up",
28
                        color = MaterialTheme.colorScheme.onPrimary,
29
                    )
30
                },
31
            )
32
        }
33
    ) { paddingValues ->
34
        Column(
35
            modifier = modifier
36
                .padding(paddingValues)
37
                .padding(20.dp)
38
        ) {
39
            val email = viewModel.email.collectAsState(initial = "")
40
            val password = viewModel.password.collectAsState()
41
            OutlinedTextField(
42
                label = {
43
                    Text(
44
                        text = "Email",
45
                        color = MaterialTheme.colorScheme.primary,
46
                        style = MaterialTheme.typography.titleMedium
47
                    )
48
                },
49
                maxLines = 1,
50
                shape = RoundedCornerShape(32),
51
                modifier = modifier.fillMaxWidth(),
52
                value = email.value,
53
                onValueChange = {
54
                    viewModel.onEmailChange(it)
55
                },
56
            )
57
            OutlinedTextField(
58
                label = {
59
                    Text(
60
                        text = "Password",
61
                        color = MaterialTheme.colorScheme.primary,
62
                        style = MaterialTheme.typography.titleMedium
63
                    )
64
                },
65
                maxLines = 1,
66
                shape = RoundedCornerShape(32),
67
                modifier = modifier
68
                    .fillMaxWidth()
69
                    .padding(top = 12.dp),
70
                value = password.value,
71
                onValueChange = {
72
                    viewModel.onPasswordChange(it)
73
                },
74
            )
75
            val localSoftwareKeyboardController = LocalSoftwareKeyboardController.current
76
            Button(modifier = modifier
77
                .fillMaxWidth()
78
                .padding(top = 12.dp),
79
                onClick = {
80
                    localSoftwareKeyboardController?.hide()
81
                    viewModel.onSignUp()
82
                    coroutineScope.launch {
83
                        snackBarHostState.showSnackbar(
84
                            message = "Create account successfully. Sign in now!",
85
                            duration = SnackbarDuration.Long
86
                        )
87
                    }
88
                }) {
89
                Text("Sign up")
90
            }
91
        }
92
    }
93
}

创建一个 SignInViewModel：

🌐 Create a SignInViewModel:

1
@HiltViewModel
2
class SignInViewModel @Inject constructor(
3
    private val authenticationRepository: AuthenticationRepository
4
) : ViewModel() {
5
6
    private val _email = MutableStateFlow("")
7
    val email: Flow<String> = _email
8
9
    private val _password = MutableStateFlow("")
10
    val password = _password
11
12
    fun onEmailChange(email: String) {
13
        _email.value = email
14
    }
15
16
    fun onPasswordChange(password: String) {
17
        _password.value = password
18
    }
19
20
    fun onSignIn() {
21
        viewModelScope.launch {
22
            authenticationRepository.signIn(
23
                email = _email.value,
24
                password = _password.value
25
            )
26
        }
27
    }
28
29
    fun onGoogleSignIn() {
30
        viewModelScope.launch {
31
            authenticationRepository.signInWithGoogle()
32
        }
33
    }
34
35
}

创建 SignInScreen.kt：

🌐 Create the SignInScreen.kt:

1
@OptIn(ExperimentalMaterial3Api::class, ExperimentalComposeUiApi::class)
2
@Composable
3
fun SignInScreen(
4
    modifier: Modifier = Modifier,
5
    navController: NavController,
6
    viewModel: SignInViewModel = hiltViewModel()
7
) {
8
    val snackBarHostState = remember { SnackbarHostState() }
9
    val coroutineScope = rememberCoroutineScope()
10
    Scaffold(
11
        snackbarHost = { androidx.compose.material.SnackbarHost(snackBarHostState) },
12
        topBar = {
13
            TopAppBar(
14
                navigationIcon = {
15
                    IconButton(onClick = {
16
                        navController.navigateUp()
17
                    }) {
18
                        Icon(
19
                            imageVector = Icons.Filled.ArrowBack,
20
                            contentDescription = null,
21
                            tint = MaterialTheme.colorScheme.onPrimary
22
                        )
23
                    }
24
                },
25
                backgroundColor = MaterialTheme.colorScheme.primary,
26
                title = {
27
                    Text(
28
                        text = "Login",
29
                        color = MaterialTheme.colorScheme.onPrimary,
30
                    )
31
                },
32
            )
33
        }
34
    ) { paddingValues ->
35
        Column(
36
            modifier = modifier
37
                .padding(paddingValues)
38
                .padding(20.dp)
39
        ) {
40
            val email = viewModel.email.collectAsState(initial = "")
41
            val password = viewModel.password.collectAsState()
42
            androidx.compose.material.OutlinedTextField(
43
                label = {
44
                    Text(
45
                        text = "Email",
46
                        color = MaterialTheme.colorScheme.primary,
47
                        style = MaterialTheme.typography.titleMedium
48
                    )
49
                },
50
                maxLines = 1,
51
                shape = RoundedCornerShape(32),
52
                modifier = modifier.fillMaxWidth(),
53
                value = email.value,
54
                onValueChange = {
55
                    viewModel.onEmailChange(it)
56
                },
57
            )
58
            androidx.compose.material.OutlinedTextField(
59
                label = {
60
                    Text(
61
                        text = "Password",
62
                        color = MaterialTheme.colorScheme.primary,
63
                        style = MaterialTheme.typography.titleMedium
64
                    )
65
                },
66
                maxLines = 1,
67
                shape = RoundedCornerShape(32),
68
                modifier = modifier
69
                    .fillMaxWidth()
70
                    .padding(top = 12.dp),
71
                value = password.value,
72
                onValueChange = {
73
                    viewModel.onPasswordChange(it)
74
                },
75
            )
76
            val localSoftwareKeyboardController = LocalSoftwareKeyboardController.current
77
            Button(modifier = modifier
78
                .fillMaxWidth()
79
                .padding(top = 12.dp),
80
                onClick = {
81
                    localSoftwareKeyboardController?.hide()
82
                    viewModel.onGoogleSignIn()
83
                }) {
84
                Text("Sign in with Google")
85
            }
86
            Button(modifier = modifier
87
                .fillMaxWidth()
88
                .padding(top = 12.dp),
89
                onClick = {
90
                    localSoftwareKeyboardController?.hide()
91
                    viewModel.onSignIn()
92
                    coroutineScope.launch {
93
                        snackBarHostState.showSnackbar(
94
                            message = "Sign in successfully !",
95
                            duration = SnackbarDuration.Long
96
                        )
97
                    }
98
                }) {
99
                Text("Sign in")
100
            }
101
            OutlinedButton(modifier = modifier
102
                .fillMaxWidth()
103
                .padding(top = 12.dp), onClick = {
104
                navController.navigate(SignUpDestination.route)
105
            }) {
106
                Text("Sign up")
107
            }
108
        }
109
    }
110
}

实现 `MainActivity`#

🌐 Implement the MainActivity

在你之前创建的 MainActivity 中，显示你新建的屏幕：

🌐 In the MainActivity you created earlier, show your newly created screens:

1
@AndroidEntryPoint
2
class MainActivity : ComponentActivity() {
3
    @Inject
4
    lateinit var supabaseClient: SupabaseClient
5
6
    @OptIn(ExperimentalMaterial3Api::class)
7
    override fun onCreate(savedInstanceState: Bundle?) {
8
        super.onCreate(savedInstanceState)
9
        setContent {
10
            ManageProductsTheme {
11
                // A surface container using the 'background' color from the theme
12
                val navController = rememberNavController()
13
                val currentBackStack by navController.currentBackStackEntryAsState()
14
                val currentDestination = currentBackStack?.destination
15
                Scaffold { innerPadding ->
16
                    NavHost(
17
                        navController,
18
                        startDestination = ProductListDestination.route,
19
                        Modifier.padding(innerPadding)
20
                    ) {
21
                        composable(ProductListDestination.route) {
22
                            ProductListScreen(
23
                                navController = navController
24
                            )
25
                        }
26
27
                        composable(AuthenticationDestination.route) {
28
                            SignInScreen(
29
                                navController = navController
30
                            )
31
                        }
32
33
                        composable(SignUpDestination.route) {
34
                            SignUpScreen(
35
                                navController = navController
36
                            )
37
                        }
38
39
                        composable(AddProductDestination.route) {
40
                            AddProductScreen(
41
                                navController = navController
42
                            )
43
                        }
44
45
                        composable(
46
                            route = "${ProductDetailsDestination.route}/{${ProductDetailsDestination.productId}}",
47
                            arguments = ProductDetailsDestination.arguments
48
                        ) { navBackStackEntry ->
49
                            val productId =
50
                                navBackStackEntry.arguments?.getString(ProductDetailsDestination.productId)
51
                            ProductDetailsScreen(
52
                                productId = productId,
53
                                navController = navController,
54
                            )
55
                        }
56
                    }
57
                }
58
            }
59
        }
60
    }
61
}

创建成功屏幕 #

🌐 Create the success screen

要处理 OAuth 和 OTP 登录，创建一个新活动来处理你在 AndroidManifest.xml 中设置的深度链接：

🌐 To handle OAuth and OTP signins, create a new activity to handle the deep link you set in AndroidManifest.xml:

1
<?xml version="1.0" encoding="utf-8"?>
2
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
3
    xmlns:tools="http://schemas.android.com/tools">
4
    <uses-permission android:name="android.permission.INTERNET" />
5
    <application
6
        android:name=".ManageProductApplication"
7
        android:allowBackup="true"
8
        android:dataExtractionRules="@xml/data_extraction_rules"
9
        android:enableOnBackInvokedCallback="true"
10
        android:fullBackupContent="@xml/backup_rules"
11
        android:icon="@mipmap/ic_launcher"
12
        android:label="@string/app_name"
13
        android:supportsRtl="true"
14
        android:theme="@style/Theme.ManageProducts"
15
        tools:targetApi="31">
16
        <activity
17
            android:name=".DeepLinkHandlerActivity"
18
            android:exported="true"
19
            android:theme="@style/Theme.ManageProducts" >
20
            <intent-filter android:autoVerify="true">
21
                <action android:name="android.intent.action.VIEW" />
22
                <category android:name="android.intent.category.DEFAULT" />
23
                <category android:name="android.intent.category.BROWSABLE" />
24
                <data
25
                    android:host="supabase.com"
26
                    android:scheme="app" />
27
            </intent-filter>
28
        </activity>
29
        <activity
30
            android:name=".MainActivity"
31
            android:exported="true"
32
            android:label="@string/app_name"
33
            android:theme="@style/Theme.ManageProducts">
34
            <intent-filter>
35
                <action android:name="android.intent.action.MAIN" />
36
                <category android:name="android.intent.category.LAUNCHER" />
37
            </intent-filter>
38
        </activity>
39
    </application>
40
</manifest>

然后创建 DeepLinkHandlerActivity：

🌐 Then create the DeepLinkHandlerActivity:

1
@AndroidEntryPoint
2
class DeepLinkHandlerActivity : ComponentActivity() {
3
4
    @Inject
5
    lateinit var supabaseClient: SupabaseClient
6
7
    private lateinit var callback: (String, String) -> Unit
8
9
    override fun onCreate(savedInstanceState: Bundle?) {
10
        super.onCreate(savedInstanceState)
11
        supabaseClient.handleDeeplinks(intent = intent,
12
            onSessionSuccess = { userSession ->
13
                Log.d("LOGIN", "Log in successfully with user info: ${userSession.user}")
14
                userSession.user?.apply {
15
                    callback(email ?: "", createdAt.toString())
16
                }
17
            })
18
        setContent {
19
            val navController = rememberNavController()
20
            val emailState = remember { mutableStateOf("") }
21
            val createdAtState = remember { mutableStateOf("") }
22
            LaunchedEffect(Unit) {
23
                callback = { email, created ->
24
                    emailState.value = email
25
                    createdAtState.value = created
26
                }
27
            }
28
            ManageProductsTheme {
29
                Surface(
30
                    modifier = Modifier.fillMaxSize(),
31
                    color = MaterialTheme.colorScheme.background
32
                ) {
33
                    SignInSuccessScreen(
34
                        modifier = Modifier.padding(20.dp),
35
                        navController = navController,
36
                        email = emailState.value,
37
                        createdAt = createdAtState.value,
38
                        onClick = { navigateToMainApp() }
39
                    )
40
                }
41
            }
42
        }
43
    }
44
45
    private fun navigateToMainApp() {
46
        val intent = Intent(this, MainActivity::class.java).apply {
47
            flags = Intent.FLAG_ACTIVITY_CLEAR_TOP
48
        }
49
        startActivity(intent)
50
    }
51
}