Android--广播接收者（发送有序广播）

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1、运行效果图

当点击发送求救广播按钮时

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创建步骤如下

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1、在layout布局中：

<?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:paddingBottom="@dimen/activity_vertical_margin"
android:background="@drawable/stitch_one"
    tools:context="cn.edu.bzu.orderedbroadcast.MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:onClick="send"
        android:layout_marginTop="50dp"
        android:text="发送求救广播"
        android:paddingLeft="5dp"
        android:paddingRight="5dp"
        android:background="#FFD202"
        android:textSize="20sp"
        />
</RelativeLayout>

1、在MainActivity中：

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();
        //定义广播事件类型
        intent.setAction("Intercept_Stitch");
        //发送广播
       sendOrderedBroadcast(intent,null);
    }
}

2、在MyBroadcastReciveOne

package cn.edu.bzu.orderedbroadcast;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
public class MyBroadcastReceiverOne extends BroadcastReceiver {
    public MyBroadcastReceiverOne() {
    }
    @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");
    }
}

2、在MyBroadcastReciveTwo

package cn.edu.bzu.orderedbroadcast;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
public class MyBroadcastReceiverTwo extends BroadcastReceiver {
    public MyBroadcastReceiverTwo() {
    }
    @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");
        abortBroadcast();
        Log.i("MyBroadcastReceiverTwo","我是广播接收者Two我的拦截被终止了");
    }
}

3、在MyBroadcastReciveThree

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

4、重要：在配置文件中

<?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>

注意：

<intent-filter android:priority="600">
                <action android:name="Intercept_Stitch"/>
            </intent-filter>

1. 优先级的概念用于描述控件的 intent的filter的类型。 这个属性只对activity 和 receivers 是有意义的。
2. 隐式调用activity的情况下： 如果多个activity 满足响应 的条件， 系统只会触发 priority 高的那个activity。
3. 有序广播发出的情况下：如果多个receiver满足响应的条件，系统会优先触发prioriyt搞的那个receiver。
4. priority 必须是整数，默认是0 范围是[-1000, 1000]
5. 有序广播，即从优先级别最高的广播接收器开始接收，接收完了如果没有丢弃，就下传给下一个次高优先级别的广播接收器进行处理，依次类推，直到最后。如果多个应用程序设置的优先级别相同，则谁先注册的广播，谁就可以优先接收到广播。