java Android DownloadManager 获取文件名

Android DownloadManager get filename

提问by

In my app you can download some files. I used the Android DownloadManagerclass for downloading. After the download is completed, it should show me a message that the file was downloaded. The problem is, there could be 2,3 or 4 downloads at the same time. My BroadcastReceivercode looks like this:

在我的应用程序中，您可以下载一些文件。我使用 AndroidDownloadManager类进行下载。下载完成后，它应该向我显示文件已下载的消息。问题是，可能同时进行 2,3 或 4 次下载。我的BroadcastReceiver代码如下所示：

receiver_complete = new BroadcastReceiver(){
         @Override
          public void onReceive(Context context, Intent intent) {
             String action = intent.getAction();
                if (action.equals(DownloadManager.ACTION_DOWNLOAD_COMPLETE) ){
                    Toast.makeText(MainActivity.this, MainActivity.this.getString(R.string.download_finished, "Here should be the name", Toast.LENGTH_SHORT).show();
                }
         }
     };

How can I get the current filename of the finished download?

如何获取已完成下载的当前文件名？

Thank you very much.

非常感谢你。

采纳答案by Ian Shannon

I think you want to put something like this inside your ifblock. Replace YOUR_DMwith your DownloadManager instance.

我想你想把这样的东西放在你的if块里。替换YOUR_DM为您的 DownloadManager 实例。

Bundle extras = intent.getExtras();
DownloadManager.Query q = new DownloadManager.Query();
q.setFilterById(extras.getLong(DownloadManager.EXTRA_DOWNLOAD_ID));
Cursor c = YOUR_DM.query(q);

if (c.moveToFirst()) {
    int status = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS));
    if (status == DownloadManager.STATUS_SUCCESSFUL) {
        // process download
        title = c.getString(c.getColumnIndex(DownloadManager.COLUMN_TITLE));
        // get other required data by changing the constant passed to getColumnIndex
    }
}

回答by Mario Velasco

Ian Shannon was totally right with his answer, but I sugest some improvement:

伊恩·香农 (Ian Shannon) 的回答完全正确，但我建议有一些改进：

• Remember to close that Cursorafter using it, avoiding "Cursor Leaking". This Cursorconsumes a lot of resources and must be released as soon as possible.

• If you put some title for the download, such as:

  DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
  request.setTitle("Some title");
  

  The value given by the DownloadManager.COLUMN_TITLEwill be "Some title"instead of the file name. So I would recommend this instead:

  String filePath = c.getString(c.getColumnIndex(DownloadManager.COLUMN_LOCAL_FILENAME));
  title = filePath.substring( filePath.lastIndexOf('/')+1, filePath.length() );
  

  The COLUMN_LOCAL_FILENAMEreturns the entire path (/storage/sdcard0/Android/data/.../filename.ext), but with this code, we will only get the file name.

• Cursor使用后记得关闭它，避免“光标泄漏”。这Cursor会消耗大量资源，必须尽快释放。

• 如果您为下载添加了一些标题，例如：

  DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
  request.setTitle("Some title");
  

  给出的值DownloadManager.COLUMN_TITLE将"Some title"代替文件名。所以我会推荐这个：

  String filePath = c.getString(c.getColumnIndex(DownloadManager.COLUMN_LOCAL_FILENAME));
  title = filePath.substring( filePath.lastIndexOf('/')+1, filePath.length() );
  

  在COLUMN_LOCAL_FILENAME返回的整个路径（/storage/sdcard0/Android/data/.../filename.ext），但与此代码，我们将只得到文件名。

Final code:

最终代码：

Bundle extras = intent.getExtras();
DownloadManager.Query q = new DownloadManager.Query();
q.setFilterById(extras.getLong(DownloadManager.EXTRA_DOWNLOAD_ID));
Cursor c = YOUR_DM.query(q);

if (c.moveToFirst()) {
    int status = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS));
    if (status == DownloadManager.STATUS_SUCCESSFUL) {
        String filePath = c.getString(c.getColumnIndex(DownloadManager.COLUMN_LOCAL_FILENAME));
        filename = filePath.substring( filePath.lastIndexOf('/')+1, filePath.length() );
    }
}
c.close();

Edit:Replace YOUR_DM with your DownloadManager instance.

编辑：将 YOUR_DM 替换为您的 DownloadManager 实例。

回答by Siddharth Lele

I think what you are looking for is the DownloadManager.COLUMN_TITLE

我认为你正在寻找的是 DownloadManager.COLUMN_TITLE

Here is a link to the Android Documents: http://developer.android.com/reference/android/app/DownloadManager.html#COLUMN_TITLE

这是 Android 文档的链接：http: //developer.android.com/reference/android/app/DownloadManager.html#COLUMN_TITLE

And here is a tutorial that will explain more than just getting the title. It is for downloading an image from a URL and then displaying it in an application. Mighty useful I think, overall speaking.

这是一个教程，不仅可以解释获得标题，还可以解释更多内容。它用于从 URL 下载图像，然后在应用程序中显示它。总的来说，我认为非常有用。

http://wptrafficanalyzer.in/blog/downloading-an-image-from-an-http-url-using-downloadmanager-and-displaying-in-imageview-by-dynamically-registered-broadcastreceiver/

http://wptrafficanalyzer.in/blog/downloading-an-image-from-an-http-url-using-downloadmanager-and-displaying-in-imageview-by-dynamically-registered-broadcastreceiver/

回答by Sean Pianka

There's a simpler way to retrieve the downloaded file URI, and that is with getUriForDownloadedFile:

有一种更简单的方法来检索下载的文件 URI，那就是getUriForDownloadedFile：

download_receiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        Bundle b = intent.getExtras();
        DownloadManager dm = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
        long file_id = b.getLong(DownloadManager.EXTRA_DOWNLOAD_ID);
        Uri uri = dm.getUriForDownloadedFile(downloaded_file_id);

    }
}

I found this method herein a full description of how to use a BroadcastReceiver for handling DOWNLOAD_COMPLETE events.

我发现这个方法在这里在如何使用用于处理DOWNLOAD_COMPLETE事件广播接收器的完整描述。

回答by Nithinlal

u try this code to get the file name

你试试这个代码来获取文件名

DownloadManager.COLUMN_LOCAL_FILENAME

下载管理器.COLUMN_LOCAL_FILENAME

i am not sure about it

我不确定