广播你发送我接受for Android(BroadcastRec

1.看这篇文章之前请先看上一篇
http://www.jianshu.com/p/fbe6ee0af9c3?utm_campaign=haruki&utm_content=note&utm_medium=reader_share&utm_source=qq
好，我们回归正题
首先，我们建立一个项目，用来发送，建立一个按钮用来充当触发器
添加MainActivity中代码，给按钮添加监听然后发送代码如下

package mylistview.lmq.cn.broadcasttest2;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity01 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main01);
        Button button=findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent("com.example.broadcasttest.MY_BROADCAST");
                sendBroadcast(intent);
            }
        });
    }
}

2.我们新建一个项目，按照第一个文章的方法建立一个接收者
在其中显示信息，我这里打印为 i have already receiver。
代码同第一篇文章，我将其贴在这，注意发送和接受的广播是同一种，这里为com.example.broadcasttest.MY_BROADCAST

package mylistview.lmq.cn.broadcastreciver;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class MyReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO: This method is called when the BroadcastReceiver is receiving
        // an Intent broadcast.
        Toast.makeText(context,"i hava aleadly reciver",Toast.LENGTH_SHORT).show();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="mylistview.lmq.cn.broadcastreciver">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        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=".MyReceiver"
            android:enabled="true"
            android:exported="true">

                <intent-filter>
                    <action android:name="com.example.broadcasttest.MY_BROADCAST"/>
                </intent-filter>

        </receiver>
    </application>

</manifest>

3.分别运行两个程序后，点击发送者的按钮，你会发现底下会打印出一条信息

4.发送有序广播
在你建立多个接收者的时候你会发现，打印信息都会出来，但是顺序是怎样的呢？所以这里我们给他们规定一下优先级
在接收者的配置文件中加上优先级代码priority=""如下：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="mylistview.lmq.cn.broadcastreciver2">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity01">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <receiver
            android:name=".MyReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter android:priority="100">//这里我添加的是100
                                                //，数字越大，优先级越高
                <action android:name="com.example.broadcasttest.MY_BROADCAST"/>
            </intent-filter>
        </receiver>
    </application>

</manifest>

运行一下你发现添加有优先级的会在前面显示了
5.我们可不可以中断呢？我只想显示一条或几条，因为是按照优先级的顺序进行显示，所以你哪一个想要阻断，后面优先级低的就不会显示了，
很简单添加一个方法就可以
abortBroadcast()；

package mylistview.lmq.cn.broadcastreciver2;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class MyReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO: This method is called when the BroadcastReceiver is receiving
        // an Intent broadcast.
        Toast.makeText(context,"i hava alrealy reciver 2",Toast.LENGTH_SHORT).show();
        abortBroadcast();//阻断传递
    }
}