android 51 有序广播

无序广播：一条广播发送出去，多个接收者接收没有顺序。
有序广播：广播接收者可以设置优先级，优先级高的先收到广播。
有序广播可以设置优先级。

mainActivity.java

package com.sxt.day07_06;

import android.os.Bundle;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.util.Log;
import android.view.Menu;

public class MainActivity extends Activity {
    ThirdReceiver mReceiver;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        registgerReceiver();
        Intent intent=new Intent("com.sxt.day07_06.order_broadcast");
        intent.putExtra("key", "hello java");
        sendOrderedBroadcast(intent, null);//发送有序广播
    }
    //注册第三级别的广播接收者，第一第二级别的广播接收者在系统说明文件中注册，
    private void registgerReceiver() {
        mReceiver=new ThirdReceiver();
        IntentFilter filter=new IntentFilter("com.sxt.day07_06.order_broadcast");//com.sxt.day07_06.order_broadcast广播的字符串
        filter.setPriority(600);//设置优先级
        registerReceiver(mReceiver, filter);
    }
    //java定义的第三级别的广播接收这
    class ThirdReceiver extends BroadcastReceiver{
        public void onReceive(Context context, android.content.Intent intent) {
            Log.i("main","ThirdReceiver.onReceive()");
        };
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(mReceiver);//销毁的时候取消注册的广播接收者，释放资源。
    }
}

第一个广播接收者：

package com.sxt.day07_06;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

public class FirstReceiver extends BroadcastReceiver {

    @Override
    //优先级第一的广播接收者
    public void onReceive(Context context, Intent intent) {
        String value=intent.getStringExtra("key");//mainActivity的字符串
        Log.i("main","FirstReceiver.onReceive():"+value);
        setResultData("来源于FirstReceiver的文本");//向第二级别的广播接收者发送字符串，
    }

}

第二个广播接收者：

package com.sxt.day07_06;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

public class SecondReceiver extends BroadcastReceiver {

    @Override
    //优先级第二的广播接收者
    public void onReceive(Context context, Intent intent) {
        String value=intent.getStringExtra("key");//mainActivity的字符串
        String text=getResultData();//第一级别广播接收者发过来的数据
        Log.i("main","SecondReceiver.onReceive(),intent中携带的文本:"+value+","+text);
        if(isOrderedBroadcast()){//如果收到的广播是有序广播
            abortBroadcast();//终止广播
        }
    }

}

系统描述文件：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.sxt.day07_06"
    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.sxt.day07_06.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <receiver android:name="com.sxt.day07_06.FirstReceiver">   注册广播接收者
            <intent-filter android:priority="800">
                <action android:name="com.sxt.day07_06.order_broadcast"/>
            </intent-filter>
        </receiver>
        <receiver android:name="com.sxt.day07_06.SecondReceiver">
            <intent-filter android:priority="700">
                <action android:name="com.sxt.day07_06.order_broadcast"/>
            </intent-filter>
        </receiver>
    </application>

</manifest>