案例-----拦截有序广播

1.创建程序
程序对应的布局文件（activity_main.xml）如下所示：

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"   android:background="@drawable/stitch_one"    tools:context="cn.edu.bzu.orderedbroadcast.MainActivity">    <Button        android:text="发送有序广播"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_centerHorizontal="true"        android:layout_marginTop="80dp"        android:onClick="send"        android:paddingLeft="5dp"        android:paddingRight="5dp"        android:background="#FBFBFF"        android:textSize="20sp"        android:id="@+id/button" /></RelativeLayout>

2.添加广播接受者

添加三个广播接收者MyBroadcastReceiverOne,MyBroadcastReceiverTwo,MyBroadcastReceiverThree,不同的广播接收者打印不同的提示信息。
MyBroadcastReceiverOne的代码如下：

package cn.edu.bzu.orderedbroadcast;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.util.Log;/** * Created by Administrator on 2017/6/2. */public class MyBroadcastReceiverOne extends BroadcastReceiver {    @Override    public void onReceive(Context context, Intent intent) {        Log.i("MyBroadcastReceiverOne","自定义的广播接收者One,接受到了广播事件");    }}

MyBroadcastReceiverTwo的代码如下：

package cn.edu.bzu.orderedbroadcast;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.util.Log;/** * Created by Administrator on 2017/6/2. */public class MyBroadcastReceiverTwo extends BroadcastReceiver {    @Override    public void onReceive(Context context, Intent intent) {        Log.i("MyBroadcastReceiverTwo","自定义的广播接收者Two,接受到了广播事件");    }}

MyBroadcastReceiverThree的代码如下：(Log.i()有时会提示出错，原因是最大支持23个字符，当方法内写成MyBroadcastReceiverThree时超出了它的容量，可以减少一个字符)

package cn.edu.bzu.orderedbroadcast;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.util.Log;/** * Created by Administrator on 2017/6/2. */public class MyBroadcastReceiverThree extends BroadcastReceiver {    @Override    public void onReceive(Context context, Intent intent) {        Log.i("MyBroadcastReceiverThre","自定义的广播接收者Three,接受到了广播事件");    }}

3.在清单文件中注册三个广播接收者并为它们指定不同的优先级，具体代码如下：

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="cn.edu.bzu.orderedbroadcast">    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:supportsRtl="true"        android:theme="@style/AppTheme">        <activity android:name=".MainActivity">            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <receiver android:name=".MyBroadcastReceiverOne">            <intent-filter android:priority="1000">                <action android:name="Intercept_Stitch"/>            </intent-filter>        </receiver>        <receiver android:name=".MyBroadcastReceiverTwo">            <intent-filter android:priority="200">                <action android:name="Intercept_Stitch"/>            </intent-filter>        </receiver>        <receiver android:name=".MyBroadcastReceiverThree">            <intent-filter android:priority="600">                <action android:name="Intercept_Stitch"/>            </intent-filter>        </receiver>    </application></manifest>

4.编写界面交互代码：

package cn.edu.bzu.orderedbroadcast;import android.content.Intent;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;public class MainActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    public void send(View view){        Intent intent=new Intent();        intent.setAction("Intercept_Stitch");        sendOrderedBroadcast(intent,null);    }}

5.运行程序拦截有序广播
观察窗口的提示信息：

优先级最高的MyBroadcastReceiverOne最先收到广播事件，其次是MyBroadcastReceiverThree,最后是MyBroadcastReceiverTwo,说明广播接收者的优先级决定广播接收的顺序。
将广播接收者MyBroadcastReceiverTwo的优先级也设置为1000，并将其的注册码放在MyBroadcastReceiverOne的前面，代码如下：

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="cn.edu.bzu.orderedbroadcast">    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:supportsRtl="true"        android:theme="@style/AppTheme">        <activity android:name=".MainActivity">            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <receiver android:name=".MyBroadcastReceiverTwo">            <intent-filter android:priority="1000">                <action android:name="Intercept_Stitch"/>            </intent-filter>        </receiver>        <receiver android:name=".MyBroadcastReceiverOne">            <intent-filter android:priority="1000">                <action android:name="Intercept_Stitch"/>            </intent-filter>        </receiver>        <receiver android:name=".MyBroadcastReceiverThree">            <intent-filter android:priority="600">                <action android:name="Intercept_Stitch"/>            </intent-filter>        </receiver>    </application></manifest>

运行结果如图：

高优先级的广播是可以被终止的，在MyBroadcastReceiverTwo添加abortBroadcast()拦截广播：

        abortBroadcast();        Log.i("MyBroadcastReceiverTwo","我是广播接收者Two，广播被我终结了");

再次运行程序，结果如下：

可以看出，只有MyBroadcastReceiverTwo接收到了自定义的广播事件，其他的广播接收者都没有接收到，因此说明广播被MyBroadcastReceiverTwo终止了。