使用FileObserver 類監聽android sd卡變動

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卡上的目錄創建監聽器
*/
public class SDCardListener extends FileObserver {
 private Context context;
public SDCardListener(Context context, String path) {

 // 這種構造方法是默認監聽所有事件的,如果使用super(String,int)這種構造方法， 則int參數是要監聽的事件類型.
 super(path);
 this.context = context;
 init();

}
/**

注冊監聽器
*/
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://監聽創建

 Log.d("Create", "path:" + path);
 rescanSdcard();
 break;

case FileObserver.DELETE://監聽刪除

 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())));

}
}</pre>