Android-自定义meta-data扩展数据

 <!-- appid -->
        <meta-data
            android:name="APP_ID"
            android:value="037810BCE1D2260F32017643AC7D980C" />

        <!-- 发布渠道(可选) -->
        <meta-data
            android:name="APP_CHANNEL"
            android:value="QQ_CENTER" />

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.wwj.metadata"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.wwj.metadata.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
            <!-- 在Activity定义的meta-data -->
            <meta-data
                android:name="myMsg"
                android:value="hello my activity" >
            </meta-data>
        </activity>

        <!-- 在Application定义的meta-data -->
        <meta-data
            android:name="myMsg"
            android:value="hello my application" >
        </meta-data>
    </application>

</manifest>

package com.wwj.metadata;

import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Bundle;

public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		//在Activity的应用
		try {
			ActivityInfo info = this.getPackageManager().getActivityInfo(
					getComponentName(), PackageManager.GET_META_DATA);
			String msg = info.metaData.getString("myMsg");
			System.out.println("myMsg:" + msg);
		} catch (NameNotFoundException e) {
			e.printStackTrace();
		}
	}
	
	
/*	1 ：在Activity的应用。
    xml代码段：
   <activity...>
       <meta-data android:name="myMsg" android:value="hello my activity"></meta-data>
    </activity>
    
    java代码段：
   ActivityInfo info=this.getPackageManager()
                          .getActivityInfo(getComponentName(),
                          PackageManager.GET_META_DATA);
    String msg=info.metaData.getString("myMsg");
    System.out.println("myMsg:"+msg);
2：在application的应用。
   xml代码段：
  <application...>
       <meta-data android:value="hello my application" android:name="myMsg"></meta-data>
   </application>
   
   java代码段：
    ApplicationInfo appInfo = this.getPackageManager()
                                  .getApplicationInfo(getPackageName(), 
                          PackageManager.GET_META_DATA);
    String msg=appInfo.metaData.getString("myMsg");
    System.out.println("myMsg:"+msg);
3：在service的应用。
   xml代码段：
   <service android:name="MetaDataService">
      <meta-data android:value="hello my service" android:name="myMsg"></meta-data>
   </service>
   java代码段：
   ComponentName cn=new ComponentName(this, MetaDataService.class);
   ServiceInfo info=this.getPackageManager()
                        .getServiceInfo(cn, PackageManager.GET_META_DATA);
    String msg=info.metaData.getString("myMsg");
    System.out.println("myMsg:"+msg);
4: 在receiver的应用。
   xml代码段:
    <receiver android:name="MetaDataReceiver">
            <meta-data android:value="hello my receiver" android:name="myMsg"></meta-data>
            <intent-filter>
                <action android:name="android.intent.action.PHONE_STATE"></action>
            </intent-filter>
    </receiver>
   java代码段：
    ComponentName cn=new ComponentName(context, MetaDataReceiver.class);
    ActivityInfo info=context.getPackageManager()
                             .getReceiverInfo(cn, PackageManager.GET_META_DATA);
    String msg=info.metaData.getString("myMsg");
    System.out.println("myMsg:"+msg);*/

}