Android笔记之manifestPlaceholders

有时根据项目需要，AndroidManifest.xml中的meta-data的值分测试和正式

为了能自动地更换meta-data值，就需要用到manifestPlaceholders

语法：manifestPlaceholders = [FieldName: FieldValue]

示例如下

build.gradle (Module: app)

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.bu_ish.debug_release_test"
        minSdkVersion 19
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
            buildConfigField "String", "TextToShow", "\"当前处于发布模式\""
            manifestPlaceholders = [ManifestField: "发布模式下的清单字段"]
        }
        debug {
            buildConfigField "String", "TextToShow", "\"当前处于调试模式\""
            manifestPlaceholders = [ManifestField: "调试模式下的清单字段"]
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.bu_ish.debug_release_test">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <meta-data
            android:name="ManifestField"
            android:value="${ManifestField}" />
    </application>

</manifest>

上例中，名为ManifestField的meta-data的值为"发布模式下的清单字段"（Release模式下）或"调试模式下的清单字段"（Debug模式下）

获取该meta-data的示例如下

                try {
                    String manifestField = getPackageManager().getApplicationInfo(getPackageName(), PackageManager.GET_META_DATA).metaData.getString("ManifestField");
                    new AlertDialog.Builder(MainActivity.this).setMessage(manifestField).show();
                } catch (PackageManager.NameNotFoundException ex) {
                    Log.e(TAG, null, ex);
                }