Android_07_监控SD卡的状态

MainActivity.java

package com.itheima.sdlistener;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}

}

SDStatusReceiver.java
package com.itheima.sdlistener;

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

public class SDStatusReceiver extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {
//判断收到的到底是什么广播
String action = intent.getAction();
if("android.intent.action.MEDIA_MOUNTED".equals(action)){
Toast.makeText(context, "SD卡可用", 0).show();
}
else if("android.intent.action.MEDIA_REMOVED".equals(action)){
Toast.makeText(context, "SD卡拔出", 0).show();
}
else if("android.intent.action.MEDIA_UNMOUNTED".equals(action)){
Toast.makeText(context, "SD卡不可用", 0).show();
}
}

}

activity_main.xml
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

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

</RelativeLayout>注：在这里，layout布局文件实际没起作用

清单文件如下：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.itheima.sdlistener"
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.sdlistener.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>
<receiver android:name="com.itheima.sdlistener.SDStatusReceiver">
<intent-filter >
<action android:name="android.intent.action.MEDIA_MOUNTED"/>
<action android:name="android.intent.action.MEDIA_REMOVED"/>
<action android:name="android.intent.action.MEDIA_UNMOUNTED"/>
<data android:scheme="file"/>
</intent-filter>
</receiver>
</application>

</manifest>
注：记得添加如下语句，因为SD卡存在三种状态，与此同时，SD卡状态改变发送广播时，会携带data,所以需要对应地在清单文件中，声明data节点
<intent-filter >
<action android:name="android.intent.action.MEDIA_MOUNTED"/>
<action android:name="android.intent.action.MEDIA_REMOVED"/>
<action android:name="android.intent.action.MEDIA_UNMOUNTED"/>
<data android:scheme="file"/>
</intent-filter>