【转载】http://www.crazyjiang.cn/2017/09/08/android-meta-data/
在AndroidManifest.xml中，<meta-data>元素可以作为子元素，被包含在<activity>、<application> 、<service>和<receiver>元素中，不同的父元素，在应用时读取的方法也不同。
在Activity应用<meta-data>元素
xml:
<activity...>
<meta-data android:name="data_Name" android:value="hello my activity"></meta-data>
</activity>
java:
ActivityInfo info = this.getPackageManager().getActivityInfo(getComponentName(), PackageManager.GET_META_DATA);
String msg = info.metaData.getString("data_Name");
在application应用<meta-data>元素
xml:
<application...>
<meta-data android:name="data_Name" android:value="hello my application"></meta-data>
</application>
java:
ApplicationInfo info = this.getPackageManager().getApplicationInfo(getPackageName(), PackageManager.GET_META_DATA);
String msg = info.metaData.getString("data_Name");
在service应用<meta-data>元素
xml:
<service android:name="MetaDataService">
<meta-data android:value="hello my service" android:name="data_Name"></meta-data>
</service>
java:
ComponentName cn = new ComponentName(this, MetaDataService.class);
ServiceInfo info = this.getPackageManager().getServiceInfo(cn, PackageManager.GET_META_DATA);
String msg = info.metaData.getString("data_Name");
在receiver应用<meta-data>元素
xml:
<receiver android:name="MetaDataReceiver">
<meta-data android:value="hello my receiver" android:name="data_Name"></meta-data>
<intent-filter>
<action android:name="android.intent.action.PHONE_STATE"></action>
</intent-filter>
</receiver>
java:
ComponentName cn = new ComponentName(context, MetaDataReceiver.class);
ActivityInfo info = context.getPackageManager().getReceiverInfo(cn, PackageManager.GET_META_DATA);
String msg = info.metaData.getString("data_Name");
