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>