Gradle 秘訣與方法

Gradle 和 Gradle 的 Android 外掛程式提供靈活功能,可用來編譯、建構及封裝 Android 應用程式或程式庫。本頁提供了一些實用提示和設定,協助您充分運用每次建構作業。如要瞭解加快建構速度的方法,請參閱「將建構速度最佳化」。

如果您是第一次使用 Gradle,請參閱「設定建構」瞭解基本方法。您也可以查看 Android 外掛程式的 DSL 參考說明文件,進一步瞭解本頁中使用的屬性。

管理專案和來源

以下設定可管理專案的模組與來源。如要進一步瞭解如何建立及管理專案和模組,請參閱「專案總覽」。

變更預設來源設定

您可以透過 sourceSets在模組層級封鎖build.gradle變更 Gradle 用來收集來源集

Groovy

android {
  ...
  sourceSets {
    // Encapsulates configurations for the main source set.
    main {
      // Changes the directory for Java sources. The default directory is
      // 'src/main/java'.
      java.srcDirs = ['other/java']

      // When you list multiple directories, Gradle uses all of them to collect
      // sources. You should avoid specifying a directory which is a parent to one
      // or more other directories you specify.
      res.srcDirs = ['other/res1', 'other/res2']

      // For each source set, you can specify only one Android manifest.
      // The following points Gradle to a different manifest for this source set.
      manifest.srcFile 'other/AndroidManifest.xml'
      ...
    }

    // Create additional blocks to configure other source sets.
    androidTest {

      // If all the files for a source set are located under a single root
      // directory, you can specify that directory using the setRoot property.
      // When gathering sources for the source set, Gradle looks only in locations
      // relative to the root directory you specify. For example, after applying
      // the configuration below for the androidTest source set, Gradle looks for
      // Java sources only in the src/tests/java/ directory.
      setRoot 'src/tests'
      ...
    }
  }
}
...

Kotlin

android {
  ...
  sourceSets {
    // Encapsulates configurations for the main source set.
    getByName("main") {
      // Changes the directory for Java sources. The default directory is
      // 'src/main/java'.
      java.setSrcDirs("other/java")

      // When you list multiple directories, Gradle uses all of them to collect
      // sources. You should avoid specifying a directory which is a parent to one
      // or more other directories you specify.
      res.setSrcDirs("other/res1", "other/res2")

      // For each source set, you can specify only one Android manifest.
      // The following points Gradle to a different manifest for this source set.
      manifest.srcFile("other/AndroidManifest.xml")
      ...
    }

    // Create additional blocks to configure other source sets.
    androidTest {

      // If all the files for a source set are located under a single root
      // directory, you can specify that directory using the setRoot property.
      // When gathering sources for the source set, Gradle looks only in locations
      // relative to the root directory you specify. For example, after applying
      // the configuration below for the androidTest source set, Gradle looks for
      // Java sources only in the src/tests/java/ directory.
      setRoot("src/tests")
      ...
    }
  }
}
...

管理程式庫和依附元件

Gradle 提供了一個可管理依附元件的可靠機制,無論所需對像是遠端程式庫或本機程式庫模組

使用依附元件設定來指定特定建構作業

如果只想為特定的建構變化版本來源集或測試來源集設定依附元件,請將依附元件設定的名稱改為大寫,並加上建構變化版本或測試來源集的名稱做為其前置字串。

Groovy

android {...}

// Creates Gradle dependency configurations to use in the dependencies block.
configurations {
  // For variants that combine a product flavor and build type, you need to
  // intitialize a placeholder for its dependency configuration.
  freeDebugRuntimeOnly{}
  ...
}

dependencies {
    // Adds an implementation dependency only to the "free" product flavor.
    freeImplementation 'com.google.firebase:firebase-ads:21.5.1'
    // Adds a runtimeOnly dependency only to the "freeDebug" build variant.
    freeDebugRuntimeOnly fileTree(dir: 'libs', include: ['*.jar'])
    // Adds a remote binary dependency only for local tests.
    testImplementation 'junit:junit:4.12'
    // Adds a remote binary dependency only for the instrumented test APK.
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.6.1'
}

Kotlin

android {...}

dependencies {
    // Use ""() notation for custom flavors and build types
    // Adds an implementation dependency only to the "free" product flavor.
    "freeImplementation"("com.google.firebase:firebase-ads:21.5.1")
    // Adds a runtimeOnly dependency only to the "freeDebug" build variant.
    "freeDebugRuntimeOnly"(fileTree("dir" to "libs", "include" to "*.jar"))
    // Adds a remote binary dependency only for local tests.
    testImplementation("junit:junit:4.12")
    // Adds a remote binary dependency only for the instrumented test APK.
    androidTestImplementation("com.android.support.test.espresso:espresso-core:3.6.1")
}

建立不同版本的應用程式

Gradle 和 Android 外掛程式可讓您設定建構版本,透過單一模組建立不同版本的應用程式。

設定動態版本代碼

根據預設,Gradle 為專案產生 APK 時,每個 APK 都會有相同的版本資訊,如同模組層級 build.gradle 檔案所指定。由於 Google Play 商店不允許同一個應用程式使用多個全都具有相同版本資訊的 APK,因此您必須確保每個 APK 都有各自專屬的 versionCode,然後再上傳至 Play 商店。

方法是在建構期間透過自訂建構邏輯為每個 APK 指派不同的版本代碼。舉例來說,為各個 ABI 建立個別 APK 時,自動的 APK 版本看起來會像這樣:

Groovy

android {
  ...
  defaultConfig {
    ...
    versionCode 4
  }
  splits {
    ...
  }
}

// Map for the version code that gives each ABI a value.
ext.abiCodes = ['armeabi-v7a':1, mips:2, x86:3]

// For per-density APKs, create a similar map like this:
// ext.densityCodes = ['hdpi': 1, 'xhdpi': 2, 'xxhdpi': 3, 'xxxhdpi': 4]

import com.android.build.OutputFile

// For each APK output variant, override versionCode with a combination of
// ext.abiCodes * 1000 + variant.versionCode. In this example, variant.versionCode
// is equal to defaultConfig.versionCode. If you configure product flavors that
// define their own versionCode, variant.versionCode uses that value instead.
android.applicationVariants.all { variant ->

  // Assigns a different version code for each output APK
  // other than the universal APK.
  variant.outputs.each { output ->

    // Stores the value of ext.abiCodes that is associated with the ABI for this variant.
    def baseAbiVersionCode =
            // Determines the ABI for this variant and returns the mapped value.
            project.ext.abiCodes.get(output.getFilter(OutputFile.ABI))

    // Because abiCodes.get() returns null for ABIs that are not mapped by ext.abiCodes,
    // the following code does not override the version code for universal APKs.
    // However, because we want universal APKs to have the lowest version code,
    // this outcome is desirable.
    if (baseAbiVersionCode != null) {

      // Assigns the new version code to versionCodeOverride, which changes the version code
      // for only the output APK, not for the variant itself. Skipping this step simply
      // causes Gradle to use the value of variant.versionCode for the APK.
      output.versionCodeOverride =
              baseAbiVersionCode * 1000 + variant.versionCode
    }
  }
}

Kotlin

android {
  ...
  defaultConfig {
    ...
    versionCode = 4
  }
  splits {
    ...
  }
}

// Map for the version code that gives each ABI a value.
val abiCodes = mapOf("armeabi-v7a" to 1, "mips" to 2, "x86" to 3)

// For per-density APKs, create a similar map like this:
// val densityCodes = mapOf("hdpi" to 1, "xhdpi" to 2, "xxhdpi" to 3, "xxxhdpi" to 4)

import com.android.build.api.variant.FilterConfiguration.FilterType.*

// For each APK output variant, override versionCode with a combination of
// abiCodes * 1000 + variant.versionCode. In this example, variant.versionCode
// is equal to defaultConfig.versionCode. If you configure product flavors that
// define their own versionCode, variant.versionCode uses that value instead.
androidComponents {
    onVariants { variant ->

        // Assigns a different version code for each output APK
        // other than the universal APK.
        variant.outputs.forEach { output ->
            val name = output.filters.find { it.filterType == ABI }?.identifier

            // Stores the value of abiCodes that is associated with the ABI for this variant.
            val baseAbiCode = abiCodes[name]
            // Because abiCodes.get() returns null for ABIs that are not mapped by ext.abiCodes,
            // the following code does not override the version code for universal APKs.
            // However, because we want universal APKs to have the lowest version code,
            // this outcome is desirable.
            if (baseAbiCode != null) {
                // Assigns the new version code to output.versionCode, which changes the version code
                // for only the output APK, not for the variant itself.
                output.versionCode.set(baseAbiCode * 1000 + (output.versionCode.get() ?: 0))
            }
        }
    }
}

結合多種變種版本

在某些情況下,您可能會想結合多種變種版本的設定。如要這麼做,您可以使用 Gradle 適用的 Android 外掛程式建立多組變種版本 (稱為「版本維度」)。

以下程式碼範例使用 flavorDimensions 屬性建立「mode」版本維度,將「完整」和「試用版」變種版本分組,以及一個「api」版本維度,依照 API 層級將變種版本設定分組。Gradle 隨後會將「mode」維度的變種版本與「api」維度的組合搭配使用。

Groovy

android {
  ...
  buildTypes {
    debug {...}
    release {...}
  }

  // Specifies the flavor dimensions you want to use. The order in which you
  // list each dimension determines its priority, from highest to lowest,
  // when Gradle merges variant sources and configurations. You must assign
  // each product flavor you configure to one of the flavor dimensions.
  flavorDimensions "api", "mode"

  productFlavors {
    demo {
      // Assigns this product flavor to the "mode" flavor dimension.
      dimension "mode"
      ...
    }

    full {
      dimension "mode"
      ...
    }

    // Configurations in the "api" product flavors override those in "mode"
    // flavors and the defaultConfig block. Gradle determines the priority
    // between flavor dimensions based on the order in which they appear next
    // to the flavorDimensions property above--the first dimension has a higher
    // priority than the second, and so on.
    minApi24 {
      dimension "api"
      minSdkVersion '24'
      // To ensure the target device receives the version of the app with
      // the highest compatible API level, assign version codes in increasing
      // value with API level. To learn more about assigning version codes to
      // support app updates and uploading to Google Play, read Multiple APK Support
      versionCode 30000 + android.defaultConfig.versionCode
      versionNameSuffix "-minApi24"
      ...
    }

    minApi23 {
      dimension "api"
      minSdkVersion '23'
      versionCode 20000  + android.defaultConfig.versionCode
      versionNameSuffix "-minApi23"
      ...
    }

    minApi21 {
      dimension "api"
      minSdkVersion '21'
      versionCode 10000  + android.defaultConfig.versionCode
      versionNameSuffix "-minApi21"
      ...
    }
  }
}
...

Kotlin

android {
  ...
  buildTypes {
    getByName("debug") {...}
    getByName("release") {...}
  }

  // Specifies the flavor dimensions you want to use. The order in which you
  // list each dimension determines its priority, from highest to lowest,
  // when Gradle merges variant sources and configurations. You must assign
  // each product flavor you configure to one of the flavor dimensions.
  flavorDimensions += listOf("api", "mode")

  productFlavors {
    create("demo") {
      // Assigns this product flavor to the "mode" flavor dimension.
      dimension = "mode"
      ...
    }

    create("full") {
      dimension = "mode"
      ...
    }

    // Configurations in the "api" product flavors override those in "mode"
    // flavors and the defaultConfig block. Gradle determines the priority
    // between flavor dimensions based on the order in which they appear next
    // to the flavorDimensions property above--the first dimension has a higher
    // priority than the second, and so on.
    create("minApi24") {
      dimension = "api"
      minSdkVersion(24)
      // To ensure the target device receives the version of the app with
      // the highest compatible API level, assign version codes in increasing
      // value with API level. To learn more about assigning version codes to
      // support app updates and uploading to Google Play, read Multiple APK Support
      versionCode = 30000 + android.defaultConfig.versionCode
      versionNameSuffix = "-minApi24"
      ...
    }

    create("minApi23") {
      dimension = "api"
      minSdkVersion(23)
      versionCode = 20000  + android.defaultConfig.versionCode
      versionNameSuffix = "-minApi23"
      ...
    }

    create("minApi21") {
      dimension = "api"
      minSdkVersion(21)
      versionCode = 10000  + android.defaultConfig.versionCode
      versionNameSuffix = "-minApi21"
      ...
    }
  }
}
...

篩選變化版本

您可以在模組的 build.gradle 檔案中使用 variantFilter 區塊篩選不想要的建構變數。下列程式碼範例會指示 Gradle 不要建構具有「minApi21」和「demo」兩者變種版本的變化版本:

Groovy

android {
  ...
  buildTypes {...}

  flavorDimensions "api", "mode"
  productFlavors {
    demo {...}
    full {...}
    minApi24 {...}
    minApi23 {...}
    minApi21 {...}
  }

  variantFilter { variant ->
      def names = variant.flavors*.name
      // To check for a certain build type, use variant.buildType.name == "<buildType>"
      if (names.contains("minApi21") && names.contains("demo")) {
          // Gradle ignores any variants that satisfy the conditions above.
          setIgnore(true)
      }
  }
}
...

Kotlin

android {
  ...
  buildTypes {...}

  flavorDimensions "api", "mode"
  productFlavors {
    create("demo") {...}
    create("full") {...}
    create("minApi24") {...}
    create("minApi23") {...}
    create("minApi21") {...}
  }
}

androidComponents {
    beforeVariants { variantBuilder ->
        // To check for a certain build type, use variantBuilder.buildType == "<buildType>"
        if (variantBuilder.productFlavors.containsAll(listOf("api" to "minApi21", "mode" to "demo"))) {
            // Gradle ignores any variants that satisfy the conditions above.
            variantBuilder.enabled = false
        }
    }
}
...

測試應用程式

如要進一步瞭解如何執行本機和整合式單元測試,請參閱「測試應用程式」。

設定 Lint 選項

您可以在模組層級 build.gradle 檔案中使用 lintOptions 區塊來設定特定的 Lint 選項。如要進一步瞭解如何為您的 Android 專案執行 Lint,請參閱「使用 Lint 改善程式碼」。

Groovy

android {
    ...
    lintOptions {
        // Turns off checks for the issue IDs you specify.
        disable 'TypographyFractions','TypographyQuotes'
        // Turns on checks for the issue IDs you specify. These checks are in
        // addition to the default lint checks.
        enable 'RtlHardcoded','RtlCompat', 'RtlEnabled'
        // To enable checks for only a subset of issue IDs and ignore all others,
        // list the issue IDs with the 'check' property instead. This property overrides
        // any issue IDs you enable or disable using the properties above.
        checkOnly 'NewApi', 'InlinedApi'
        // If set to true, turns off analysis progress reporting by lint.
        quiet true
        // if set to true (default), stops the build if errors are found.
        abortOnError false
        // if true, only report errors.
        ignoreWarnings true
    }
}
...

Kotlin

android {
    ...
    lintOptions {
        // Turns off checks for the issue IDs you specify.
        disable("TypographyFractions")
        disable("TypographyQuotes")
        // Turns on checks for the issue IDs you specify. These checks are in
        // addition to the default lint checks.
        enable("RtlHardcoded")
        enable("RtlCompat")
        enable("RtlEnabled")
        // To enable checks for only a subset of issue IDs and ignore all others,
        // list the issue IDs with the 'check' property instead. This property overrides
        // any issue IDs you enable or disable using the properties above.
        checkOnly("NewApi", "InlinedApi")
        // If set to true, turns off analysis progress reporting by lint.
        quiet = true
        // if set to true (default), stops the build if errors are found.
        abortOnError = false
        // if true, only report errors.
        ignoreWarnings = true
    }
}
...

設定檢測資訊清單設定

Gradle 建構測試 APK 時,會自動產生 AndroidManifest.xml 檔案,並使用 <instrumentation> 節點進行設定。如要變更這個節點的部分設定,可以在測試來源集中建立另一個資訊清單檔案,或是設定模組層級的 build.gradle 檔案,如以下程式碼範例。

Groovy

android {
  ...
  // Each product flavor you configure can override properties in the
  // defaultConfig block. To learn more, go to Configure Product Flavors.
  defaultConfig {
    ...
    // Specifies the application ID for the test APK.
    testApplicationId "com.test.foo"
    // Specifies the fully-qualified class name of the test instrumentation runner.
    testInstrumentationRunner "android.test.InstrumentationTestRunner"
    // If set to 'true', enables the instrumentation class to start and stop profiling.
    // If set to false (default), profiling occurs the entire time the instrumentation
    // class is running.
    testHandleProfiling true
    // If set to 'true', indicates that the Android system should run the instrumentation
    // class as a functional test. The default value is 'false'
    testFunctionalTest true
  }
}
...

Kotlin

android {
  ...
  // Each product flavor you configure can override properties in the
  // defaultConfig block. To learn more, go to Configure Product Flavors.
  defaultConfig {
    ...
    // Specifies the application ID for the test APK.
    testApplicationId = "com.test.foo"
    // Specifies the fully-qualified class name of the test instrumentation runner.
    testInstrumentationRunner = "android.test.InstrumentationTestRunner"
    // If set to 'true', enables the instrumentation class to start and stop profiling.
    // If set to false (default), profiling occurs the entire time the instrumentation
    // class is running.
    testHandleProfiling = true
    // If set to 'true', indicates that the Android system should run the instrumentation
    // class as a functional test. The default value is 'false'
    testFunctionalTest = true
  }
}
...

變更測試版本類型

根據預設,所有測試都會以偵錯建構類型執行。您可以在模組層級 build.gradle 檔案中使用 testBuildType 屬性,將此類型變更為其他建構類型。 舉例來說,如果您想對「測試」版本類型執行測試,請編輯以下程式碼片段所示的檔案。

Groovy

android {
    ...
    testBuildType "staging"
}

Kotlin

android {
    ...
    testBuildType "staging"
}

設定 Gradle 測試選項

如要指定變更 Gradle 執行所有測試的方式,請在模組層級 build.gradle 中設定 testOptions 區塊。

Groovy

android {
  ...
  // Encapsulates options for running tests.
  testOptions {
    // Changes the directory where Gradle saves test reports. By default, Gradle saves test reports
    // in the path_to_your_project/module_name/build/outputs/reports/ directory.
    // '$rootDir' sets the path relative to the root directory of the current project.
    reportDir "$rootDir/test-reports"
    // Changes the directory where Gradle saves test results. By default, Gradle saves test results
    // in the path_to_your_project/module_name/build/outputs/test-results/ directory.
    // '$rootDir' sets the path relative to the root directory of the current project.
    resultsDir "$rootDir/test-results"
  }
}

Kotlin

android {
  ...
  // Encapsulates options for running tests.
  testOptions {
    // Changes the directory where Gradle saves test reports. By default, Gradle saves test reports
    // in the path_to_your_project/module_name/build/outputs/reports/ directory.
    // '$rootDir' sets the path relative to the root directory of the current project.
    reportDir "$rootDir/test-reports"
    // Changes the directory where Gradle saves test results. By default, Gradle saves test results
    // in the path_to_your_project/module_name/build/outputs/test-results/ directory.
    // '$rootDir' sets the path relative to the root directory of the current project.
    resultsDir "$rootDir/test-results"
  }
}

如果只要指定本機單元測試的選項,請設定 testOptions.unitTests 區塊。

Groovy

android {
  ...
  testOptions {
    ...
    // Encapsulates options for local unit tests.
    unitTests {
      // By default, local unit tests throw an exception any time the code you are testing tries to access
      // Android platform APIs (unless you mock Android dependencies yourself or with a testing
      // framework like Mockito). However, you can enable the following property so that the test
      // returns either null or zero when accessing platform APIs, rather than throwing an exception.
      returnDefaultValues true

      // Encapsulates options for controlling how Gradle executes local unit tests. For a list
      // of all the options you can specify, read Gradle's reference documentation.
      all {
        // Sets JVM argument(s) for the test JVM(s).
        jvmArgs '-XX:MaxPermSize=256m'

        // You can also check the task name to apply options to only the tests you specify.
        if (it.name == 'testDebugUnitTest') {
          systemProperty 'debug', 'true'
        }
      }
    }
  }
}

Kotlin

android {
  ...
  testOptions {
    ...
    // Encapsulates options for local unit tests.
    unitTests {
      // By default, local unit tests throw an exception any time the code you are testing tries to access
      // Android platform APIs (unless you mock Android dependencies yourself or with a testing
      // framework like Mockito). However, you can enable the following property so that the test
      // returns either null or zero when accessing platform APIs, rather than throwing an exception.
      returnDefaultValues true

      // Encapsulates options for controlling how Gradle executes local unit tests. For a list
      // of all the options you can specify, read Gradle's reference documentation.
      all {
        // Sets JVM argument(s) for the test JVM(s).
        jvmArgs '-XX:MaxPermSize=256m'

        // You can also check the task name to apply options to only the tests you specify.
        if (it.name == 'testDebugUnitTest') {
          systemProperty 'debug', 'true'
        }
      }
    }
  }
}

最佳化您的建構作業

本節提供一些設定,協助您更快完成完整版與累加版本。詳情請參閱「最佳化建構速度」。

縮減程式碼

Android Studio 會使用 R8 來存取 ProGuard 規則檔案,進而縮減程式碼。如果是新專案,Android Studio 會使用 Android SDK 的 tools/proguard/folder 的預設設定檔 (proguard-android.txt)。如要進一步縮減程式碼,請嘗試位於相同位置的 proguard-android-optimize.txt 檔案。

Groovy

android {
  buildTypes {
    release {
      minifyEnabled true
      proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'),
                                           'proguard-rules.pro'
    }
  }
  ...
}
...

Kotlin

android {
  buildTypes {
    release {
      minifyEnabled true
      proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'),
                                           'proguard-rules.pro'
    }
  }
  ...
}
...

如要新增各建構變化版本專屬的規則,請為每個樣式設定額外的 proguardFiles 屬性。例如,以下範例會將 flavor2-rules.pro 新增至「flavor2」。現在,「flavor2」的發布版本會使用全部三個規則檔案,因為系統也套用了發布區塊中的檔案。

Groovy

android {
  ...
  buildTypes {
    release {
      minifyEnabled true
      proguardFiles getDefaultProguardFile('proguard-android.txt'),
             'proguard-rules.pro'
    }
  }
  productFlavors {
    flavor1 {
      ...
    }
    flavor2 {
      proguardFile 'flavor2-rules.pro'
    }
  }
}
...

Kotlin

android {
  ...
  buildTypes {
    release {
      minifyEnabled true
      proguardFiles getDefaultProguardFile('proguard-android.txt'),
             'proguard-rules.pro'
    }
  }
  productFlavors {
    flavor1 {
      ...
    }
    flavor2 {
      proguardFile 'flavor2-rules.pro'
    }
  }
}
...

發布應用程式

如要進一步瞭解如何將應用程式發布到 Google Play,請參閱「發布應用程式」。

簽署應用程式

雖然 Android Studio 提供簡單的方法,讓您透過 UI 為發布子版本設定簽署,不過您仍可以手動設定模組 build.gradle 檔案中的 signingConfigs 區塊:

Groovy

android {
  ...
  defaultConfig { ... }

  // Encapsulates signing configurations.
  signingConfigs {
    // Creates a signing configuration called "release".
    release {
      // Specifies the path to your keystore file.
      storeFile file("my-release-key.jks")
      // Specifies the password for your keystore.
      storePassword "password"
      // Specifies the identifying name for your key.
      keyAlias "my-alias"
      // Specifies the password for your key.
      keyPassword "password"
    }
  }
  buildTypes {
    release {
      // Adds the "release" signing configuration to the release build type.
      signingConfig signingConfigs.release
      ...
    }
  }
}
...

Kotlin

android {
  ...
  defaultConfig { ... }

  // Encapsulates signing configurations.
  signingConfigs {
    // Creates a signing configuration called "release".
    release {
      // Specifies the path to your keystore file.
      storeFile file("my-release-key.jks")
      // Specifies the password for your keystore.
      storePassword "password"
      // Specifies the identifying name for your key.
      keyAlias "my-alias"
      // Specifies the password for your key.
      keyPassword "password"
    }
  }
  buildTypes {
    release {
      // Adds the "release" signing configuration to the release build type.
      signingConfig signingConfigs.release
      ...
    }
  }
}
...

從專案中移除私人簽署資訊

在預設的情況下,簽署設定會以純文字記錄到模組的 build.gradle 檔案中。如果您與團隊或開放原始碼專案合作,可以按照下列步驟將這項機密資訊移出建構檔案。

  1. 在專案的根目錄中建立名為 keystore.properties 的檔案,並提供下列資訊:
    storePassword=myStorePassword
    keyPassword=myKeyPassword
    keyAlias=myKeyAlias
    storeFile=myStoreFileLocation
    
  2. build.gradle 檔案中,按照下方步驟載入 keystore.properties 檔案 (必須位於 Android 區塊之前):

    Groovy

    // Creates a variable called keystorePropertiesFile, and initializes it to the
    // keystore.properties file.
    def keystorePropertiesFile = rootProject.file("keystore.properties")
    
    // Initializes a new Properties() object called keystoreProperties.
    def keystoreProperties = new Properties()
    
    // Loads the keystore.properties file into the keystoreProperties object.
    keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
    
    android {
      ...
    }
    ...

    Kotlin

    // Creates a variable called keystorePropertiesFile, and initializes it to the
    // keystore.properties file.
    def keystorePropertiesFile = rootProject.file("keystore.properties")
    
    // Initializes a new Properties() object called keystoreProperties.
    def keystoreProperties = new Properties()
    
    // Loads the keystore.properties file into the keystoreProperties object.
    keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
    
    android {
      ...
    }
    ...
  3. 輸入 keystoreProperties 物件中儲存的簽署資訊:

    Groovy

    android {
      signingConfigs {
        config {
          keyAlias keystoreProperties['keyAlias']
          keyPassword keystoreProperties['keyPassword']
          storeFile file(keystoreProperties['storeFile'])
          storePassword keystoreProperties['storePassword']
        }
      }
      ...
    }
    ...

    Kotlin

    android {
      signingConfigs {
        config {
          keyAlias keystoreProperties['keyAlias']
          keyPassword keystoreProperties['keyPassword']
          storeFile file(keystoreProperties['storeFile'])
          storePassword keystoreProperties['storePassword']
        }
      }
      ...
    }
    ...
  4. 按一下通知列中的「Sync Now」。

如要進一步瞭解應用程式簽署,請參閱「簽署應用程式」。

簡化應用程式開發作業

下列提示可協助您輕鬆開發 Android 應用程式。

與您的應用程式程式碼共用自訂欄位和資源值

在建構時間,Gradle 會產生 BuildConfig 類別,因此應用程式程式碼可以檢查目前建構的相關資訊。您也可以使用 buildConfigField() 方法,從 Gradle 建構設定檔的 BuildConfig 類別新增自訂欄位,並在應用程式的執行階段程式碼中存取這些值。同樣地,您可以使用 resValue() 新增應用程式資源值。

Groovy

android {
  ...
  buildTypes {
    release {
      // These values are defined only for the release build, which
      // is typically used for full builds and continuous builds.
      buildConfigField("String", "BUILD_TIME", "\"${minutesSinceEpoch}\"")
      resValue("string", "build_time", "${minutesSinceEpoch}")
      ...
    }
    debug {
      // Use static values for incremental builds to ensure that
      // resource files and BuildConfig aren't rebuilt with each run.
      // If these rebuild dynamically, they can interfere with
      // Apply Changes as well as Gradle UP-TO-DATE checks.
      buildConfigField("String", "BUILD_TIME", "\"0\"")
      resValue("string", "build_time", "0")
    }
  }
}
...

Kotlin

android {
  ...
  buildTypes {
    release {
      // These values are defined only for the release build, which
      // is typically used for full builds and continuous builds.
      buildConfigField("String", "BUILD_TIME", "\"${minutesSinceEpoch}\"")
      resValue("string", "build_time", "${minutesSinceEpoch}")
      ...
    }
    debug {
      // Use static values for incremental builds to ensure that
      // resource files and BuildConfig aren't rebuilt with each run.
      // If these rebuild dynamically, they can interfere with
      // Apply Changes as well as Gradle UP-TO-DATE checks.
      buildConfigField("String", "BUILD_TIME", "\"0\"")
      resValue("string", "build_time", "0")
    }
  }
}
...

在應用程式程式碼中,您可以透過下列方式存取屬性:

Kotlin

...
Log.i(TAG, BuildConfig.BUILD_TIME)
Log.i(TAG, getString(R.string.build_time))

Java

...
Log.i(TAG, BuildConfig.BUILD_TIME);
Log.i(TAG, getString(R.string.build_time));

與資訊清單共用資源

在某些情況下,您可能需要在資訊清單和程式碼中宣告相同的屬性 (例如為 FileProvider 宣告授權時)。與其更新多個位置中的相同屬性來反映某項變更,您可以在模組的 build.gradle 檔案中定義單一屬性,讓資訊清單和程式碼同時提供該屬性,如以下範例所示。詳情請參閱「將建構變數插入資訊清單」。

Groovy

android {
  // For settings specific to a product flavor, configure these properties
  // for each flavor in the productFlavors block.
  defaultConfig {
    // Creates a property for the FileProvider authority.
    def filesAuthorityValue = applicationId + ".files"
    // Creates a placeholder property to use in the manifest.
    manifestPlaceholders =
      [filesAuthority: filesAuthorityValue]
      // Adds a new field for the authority to the BuildConfig class.
      buildConfigField("String",
                       "FILES_AUTHORITY",
                       "\"${filesAuthorityValue}\"")
  }
  ...
}
...

Kotlin

android {
  // For settings specific to a product flavor, configure these properties
  // for each flavor in the productFlavors block.
  defaultConfig {
    // Creates a property for the FileProvider authority.
    val filesAuthorityValue = applicationId + ".files"
    // Creates a placeholder property to use in the manifest.
    manifestPlaceholders["filesAuthority"] = filesAuthorityValue
      // Adds a new field for the authority to the BuildConfig class.
      buildConfigField("String",
                       "FILES_AUTHORITY",
                       "\"${filesAuthorityValue}\"")
  }
  ...
}
...

在資訊清單中按照下列說明存取預留位置:

<manifest>
  ...
  <application>
    ...
    <provider
      android:name="android.support.v4.content.FileProvider"
      android:authorities="${filesAuthority}"
      android:exported="false"
      android:grantUriPermissions="true">
      ...
    </provider>
  </application>
</manifest>

存取應用程式程式碼中的 FILES_AUTHORITY 欄位看起來會像這樣:

Kotlin

...
val contentUri: Uri = FileProvider.getUriForFile(context, BuildConfig.FILES_AUTHORITY, myFile)

Java

...
Uri contentUri = FileProvider.getUriForFile(getContext(),
  BuildConfig.FILES_AUTHORITY,
  myFile);