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我有两个活动:主要和处理。在处理活动中对文件夹中的文件名进行编辑操作,然后开始扫描以通过广播进行更新,并检查扫描何时完成。

//end batch renaming operation
//start updating media store library
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,Uri.parse("file://"+Environment.getExternalStorageDirectory()))); 
//show toast "updating"
op_media_mounted.show();
//catch when updaitng op ends
IntentFilter filter = new IntentFilter(Intent.ACTION_MEDIA_SCANNER_FINISHED);
filter.addDataScheme("file");                   
BroadcastReceiver mReceiver = (new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(Intent.ACTION_MEDIA_SCANNER_FINISHED)) {
        Toast.makeText(frm_elabora.this, "Scan complete.", Toast.LENGTH_SHORT).show();
                        }
                    }
                });
registerReceiver(mReceiver, filter);   

如果扫描正在运行,我想通过 Activity 阻止处理。我可以先检查扫描是否未运行,然后启动第二个处理活动?像这样。

Button btnstart = (Button)findViewById(R.id.btn_start);
btnstart.setOnClickListener(new View.OnClickListener() {
    public void onClick(View view) {
        if ( there_isnt_scan_for_new_media_file )
            startActivity(intent_processing);
        else{
                wait_until_ACTION_MEDIA_SCANNER_FINISHED
                startActivity(intent_processing);
        }

我需要检查这一点,因为如果我在 android 运行扫描时重命名文件,当我在处理活动中编辑文件时,最后我会在文件夹中找到大小为 0 字节的其他文件,就像更改之前一样。所以我必须等待扫描完成。我找不到解决方案。

更新:我发现了这个

    public static Uri getMediaScannerUri ()
    Since: API Level 1
    Uri for querying the state of the media scanner.

我试试这个

    //send broadcast
    sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, 
            Uri.parse("file://" +
            Environment.getExternalStorageDirectory())));
    //show media scanner state
    Toast.makeText(frm_elabora.this,
        MediaStore.getMediaScannerUri().toString(),
        Toast.LENGTH_SHORT).show();

我总是得到“content://media/none/media_scanner”......如果我在发送 ACTION_MEDIA_MOUNTED 后询问 getMediaScannerUri(),我应该得到与“content://media/none/media_scanner”不同的东西???

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1 回答 1

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did you try MEDIA_SCANNER_VOLUME

Usually when the media scanner is running this column is not null.

于 2012-03-20T13:27:47.453 回答