使用FileObserver 类监听android sd卡变动详解编程语言

import android.content.Context; 
import android.content.Intent; 
import android.content.IntentFilter; 
import android.net.Uri; 
import android.os.Environment; 
import android.os.FileObserver; 
import android.util.Log; 
 
/** 
 * sd卡上的目录创建监听器 
 */ 
public class SDCardListener extends FileObserver { 
    private Context context; 
 
    public SDCardListener(Context context, String path) { 
        // 这种构造方法是默认监听所有事件的,如果使用super(String,int)这种构造方法， 则int参数是要监听的事件类型. 
        super(path); 
        this.context = context; 
        init(); 
    } 
 
    /** 
     * 注册监听器 
     */ 
    public void init() { 
        IntentFilter intentfilter = new IntentFilter(Intent.ACTION_MEDIA_SCANNER_STARTED); 
        intentfilter.addAction(Intent.ACTION_MEDIA_SCANNER_FINISHED); 
        intentfilter.addDataScheme("file"); 
        ScanSdReceiver scanSdReceiver = new ScanSdReceiver(); 
        context.registerReceiver(scanSdReceiver, intentfilter); 
    } 
 
    @Override 
    public void onEvent(int event, String path) { 
        switch (event) { 
        case FileObserver.CREATE://监听创建 
            Log.d("Create", "path:" + path); 
            rescanSdcard(); 
            break; 
        case FileObserver.DELETE://监听删除 
            Log.d("Delete", "path:" + path); 
            rescanSdcard(); 
            break; 
        } 
    } 
 
    /** 
     * 刷新SD卡 
     */ 
    public void rescanSdcard() { 
        context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,  
                Uri.parse("file://"+ Environment.getExternalStorageDirectory().getAbsolutePath()))); 
    } 
}