在Android Studio中使用DownloadManager下载文件后，可以通过监听DownloadManager的下载完成广播来删除文件。以下是一个示例代码：

首先，在AndroidManifest.xml文件中添加以下权限和广播接收器：

然后，在你的Activity或Fragment中，创建DownloadManager并开始下载文件：

private long downloadId;
private DownloadManager downloadManager;

private void startDownload() {
    // 创建DownloadManager
    downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);

    // 创建下载请求
    DownloadManager.Request request = new DownloadManager.Request(Uri.parse("Your download URL"));
    request.setTitle("File Download");
    request.setDescription("Downloading file...");
    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
    request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "file_name.ext");

    // 将下载请求提交给DownloadManager
    downloadId = downloadManager.enqueue(request);
}

接下来，在同一个Activity或Fragment中，创建一个广播接收器来监听下载完成的广播，并在下载完成后删除文件：

public class DownloadCompleteReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        long id = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);
        if (id == downloadId) {
            // 下载完成，获取下载文件的URI
            DownloadManager.Query query = new DownloadManager.Query();
            query.setFilterById(id);
            Cursor cursor = downloadManager.query(query);
            if (cursor.moveToFirst()) {
                int status = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS));
                if (status == DownloadManager.STATUS_SUCCESSFUL) {
                    // 下载成功，获取下载文件的URI
                    String uriString = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));
                    Uri fileUri = Uri.parse(uriString);

                    // 删除下载文件
                    File file = new File(fileUri.getPath());
                    if (file.exists()) {
                        file.delete();
                    }
                }
            }
            cursor.close();
        }
    }
}

记得在Activity或Fragment的onResume()方法中注册广播接收器，在onPause()方法中注销广播接收器：

private DownloadCompleteReceiver downloadCompleteReceiver;

@Override
protected void onResume() {
    super.onResume();
    downloadCompleteReceiver = new DownloadCompleteReceiver();
    registerReceiver(downloadCompleteReceiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
}

@Override
protected void onPause() {
    super.onPause();
    unregisterReceiver(downloadCompleteReceiver);
}

这样，当DownloadManager下载文件完成后，会触发广播接收器的onReceive()方法，然后可以在该方法中删除下载的文件。