Android（java）学习笔记173：BroadcastReceiver之 BroadcastReceiver静态注册（SD卡卸载或者安装案例）和 BroadcastReceiver动态注册注销

package com.itheima.sdstatus;

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

/**
* 1.买好了一个收音机
*/
public class SDStatusReceiver extends BroadcastReceiver {

// 用来接收广播事件的，一旦广播消息到来，就会执行onreceive方法
@Override
public void onReceive(Context context, Intent intent) {
//public String getAction():返回一个action的名称
String action = intent.getAction();
if ("android.intent.action.MEDIA_UNMOUNTED".equals(action)) {
System.out.println("哈哈哈----SD卡被卸载了。");
Toast.makeText(context, "哈哈哈----SD卡被卸载了，微信头像暂不可用", 0).show();
}else if("android.intent.action.MEDIA_MOUNTED".equals(action)){
Toast.makeText(context, "哈哈哈----SD卡被挂载了", 0).show();
}
}

}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.itheima.sdstatus"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.itheima.sdstatus.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>
<!-- 2.装电池 -->
<receiver android:name="com.itheima.sdstatus.SDStatusReceiver" >
<intent-filter >
<!-- 3.调频道,这里我们可以设置多个action，监听多个广播频道 -->
<action android:name="android.intent.action.MEDIA_MOUNTED"/>
<action android:name="android.intent.action.MEDIA_UNMOUNTED"/>
<data android:scheme="file"/>
</intent-filter>
</receiver>

</application>

</manifest>

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.himi.BroadcastReceiverDemo.MainActivity" >

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />

<Button
android:id="@+id/btnSendMsg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="发送消息" />

<Button
android:id="@+id/btnReg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="注册接收器" />

<Button
android:id="@+id/btnUnreg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="注销接收器" />

</LinearLayout>

 <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.himi.BroadcastReceiverDemo"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="15"
android:targetSdkVersion="17" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".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>

</application>

</manifest>

 package com.himi.BroadcastReceiverDemo;

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

public class MyReceiver extends BroadcastReceiver {
public static final String ACTION = "com.himi.BroadcastReceiverDemo.intent.action.MyReceiver";

public MyReceiver() {

}

@Override
public void onReceive(Context context, Intent intent) {
System.out.println("接收到消息了,消息的内容是：" + intent.getStringExtra("data"));

}

}

 package com.himi.BroadcastReceiverDemo;

import android.app.Activity;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;

public class MainActivity extends Activity implements OnClickListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.btnSendMsg).setOnClickListener(this);
findViewById(R.id.btnReg).setOnClickListener(this);
findViewById(R.id.btnUnreg).setOnClickListener(this);
}

public void onClick(View v) {
switch(v.getId()) {
case R.id.btnSendMsg:
//Intent i= new Intent(this, MyReceiver.class);
Intent i = new Intent(MyReceiver.ACTION);
i.putExtra("data", "jikexueyuan");
sendBroadcast(i);
break;

case R.id.btnReg:
if(receiver == null) {
receiver = new MyReceiver();
registerReceiver(receiver, new IntentFilter(MyReceiver.ACTION));
}
break;

case R.id.btnUnreg:
if(receiver != null) {
unregisterReceiver(receiver);
receiver = null;
}
break;

}

}

private MyReceiver receiver = null;

}