有序广播与无序广播案例

1、通过一个案例来讲解有序广播与无序广播的使用。
无序广播博是完全异步的，发送广播时所有监听设广播的广播接受者都会接收到此消息，但接收的顺序不确定。
有序广播，会按接受者的优先级接收，只有一个广播接受者能接收消息，在此广播接受者中逻辑执行完毕，才会继续传递。
案例效果图如下

2、案例实现过程

布局文件：activity_main.xml

<?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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@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:layout_marginTop="80dp"
        android:onClick="send"
        android:text="发送有序广播"
        android:paddingLeft="5dp"
        android:paddingRight="5dp"
        android:background="#FBFBFF"
        android:textSize="20sp"/>
</RelativeLayout>

用户界面交互代码：MainActivity.java

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);
    }
}

广播接收：MyBroadcastReceiverOne.java,MyBroadcastReceiverTwo,MyBroadcastReceiverThree

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");
    }
}

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("MyBroadcastReceiverOne","自定义的广播接收者Two,接受到了");
    }
}

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("MyBroadcastReceiverOne","自定义的广播接收者Three,接受到了");
    }
}

清单文件

<?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>
        <!--注册广播接收者-->
        <receiver
            android:name=".MyBroadcastReceiverOne"
            android:enabled="true"
            android:exported="true">
            <intent-filter android:priority="1000">
                <action android:name="Intercept_Stitch"></action>
            </intent-filter>
        </receiver>
        <receiver
            android:name=".MyBroadcastReceiverTwo"
            android:enabled="true"
            android:exported="true">
            <intent-filter android:priority="200">
                <action android:name="Intercept_Stitch"></action>
            </intent-filter>
        </receiver>
        <receiver
            android:name=".MyBroadcastReceiverThree"
            android:enabled="true"
            android:exported="true">
            <intent-filter android:priority="600">
                <action android:name="Intercept_Stitch"></action>
            </intent-filter>
        </receiver>
    </application>

</manifest>

Logcat窗口下

按照顺序排列。若MyBroadcastReceiverTwo优先级同设为1000，并放在MyBroadcastReceiverOne前，

若改为无序广播则接收的顺序不确定。