有時候專案是在寫不出來，就想學點新的知識找點感覺。

我也是網上看到的例子，只是自己去測試了下：

說明：一般的值可以通過value屬性來指定，但是如果要指定一個資源的id，則需要使用resource屬性來配置

（1）Activity中

在AndroidMainfest,xml中：

<activity android:name=".MainActivity">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category 
 
android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
    <meta-data android:name="myMsgOfActivity" android:value="hello my activity"></meta-data>
</activity>

private void getActivityData(){
    ActivityInfo info= null;
    try {
        info = this
 
.getPackageManager().getActivityInfo(getComponentName(), PackageManager.GET_META_DATA);
} catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
}
    Log.e("myMsgOfActivity",info.metaData.getString("myMsgOfActivity"));
}

<application
android:allowBackup=
 
"true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
    <meta-data android:value="hello my application" android:name="myMsgOfApplication"></meta-data>
    //...</application>

private void getApplicationData(){
    ApplicationInfo appInfo = null;
    try {
        appInfo = this.getPackageManager().getApplicationInfo(getPackageName(), PackageManager.GET_META_DATA);
} catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
}
    Log.e("myMsgOfApplication",appInfo.metaData.getString("myMsgOfApplication"));
}

新建一個Server類：

public class MyServer extends Service {
    @Override
public IBinder onBind(Intent intent) {
        return null;
}
}

清單檔案中：

<service android:name=".MyServer">
    <meta-data android:value="hello my service" android:name="myMsgOfServer"></meta-data>
</service>>

private void getServerData(){
    ComponentName cn=new ComponentName(this, MyServer.class);
ServiceInfo info= null;
    try {
        info = this.getPackageManager().getServiceInfo(cn, PackageManager.GET_META_DATA);
} catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
}
    Log.e("myMsgOfServer",info.metaData.getString("myMsgOfServer"));
}

清單檔案中

<receiver android:name=".MyBroadReceiver">
    <meta-data android:value="hello my receiver" android:name="myMsgOfBroadReceiver"></meta-data>
    <intent-filter>
        <action android:name="android.intent.action.PHONE_STATE"></action>
    </intent-filter>
</receiver>

public class MyBroadReceiver extends BroadcastReceiver{
    @Override
public void onReceive(Context context, Intent intent) {

    }
}

java程式碼中

private void getBroadReciverData(){
    ComponentName cn=new ComponentName(this, MyBroadReceiver.class);
ActivityInfo info= null;
    try {
        info = this.getPackageManager().getReceiverInfo(cn, PackageManager.GET_META_DATA);
} catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
}
    Log.e("myMsgOfBroadReceiver",info.metaData.getString("myMsgOfBroadReceiver"));
}