我无法在上述设备中使用 DownloadManager 下载文件。相同的代码适用于所有其他设备。问题是为什么它不能只在这个设备上工作。如果这是三星特有的问题，是否有解决方法？我已经尝试更改应该进行下载的目录，但这也不起作用。
安卓操作系统：4.1.2
崩溃日志：
09-24 15:48:34.298: E/ActivityThread(19843): Failed to find provider info for downloads
09-24 15:48:34.306: D/AndroidRuntime(19843): Shutting down VM
09-24 15:48:34.337: E/AndroidRuntime(19843): FATAL EXCEPTION: main
09-24 15:48:34.337: E/AndroidRuntime(19843): java.lang.IllegalArgumentException: Unknown URL content://downloads/my_downloads
09-24 15:48:34.337: E/AndroidRuntime(19843): at android.content.ContentResolver.insert(ContentResolver.java:860)
09-24 15:48:34.337: E/AndroidRuntime(19843): at android.app.DownloadManager.enqueue(DownloadManager.java:1252)
09-24 15:48:34.337: E/AndroidRuntime(19843): at com.example.ws.appcatalog.exampleDownloadManager.startDownload(exampleDownloadManager.java:59)
09-24 15:48:34.337: E/AndroidRuntime(19843): at com.example.ws.wsUtil$GetEulaOrApkUrlTask.onPostExecute(wsUtil.java:340)
09-24 15:48:34.337: E/AndroidRuntime(19843): at com.example.ws.wsUtil$GetEulaOrApkUrlTask.onPostExecute(wsUtil.java:1)
09-24 15:48:34.337: E/AndroidRuntime(19843): at android.os.AsyncTask.finish(AsyncTask.java:631)
09-24 15:48:34.337: E/AndroidRuntime(19843): at android.os.AsyncTask.access$600(AsyncTask.java:177)
09-24 15:48:34.337: E/AndroidRuntime(19843): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
09-24 15:48:34.337: E/AndroidRuntime(19843): at android.os.Handler.dispatchMessage(Handler.java:99)
09-24 15:48:34.337: E/AndroidRuntime(19843): at android.os.Looper.loop(Looper.java:137)
09-24 15:48:34.337: E/AndroidRuntime(19843): at android.app.ActivityThread.main(ActivityThread.java:4895)
09-24 15:48:34.337: E/AndroidRuntime(19843): at java.lang.reflect.Method.invokeNative(Native Method)
09-24 15:48:34.337: E/AndroidRuntime(19843): at java.lang.reflect.Method.invoke(Method.java:511)
09-24 15:48:34.337: E/AndroidRuntime(19843): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:994)
09-24 15:48:34.337: E/AndroidRuntime(19843): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:761)
09-24 15:48:34.337: E/AndroidRuntime(19843): at dalvik.system.NativeStart.main(Native Method)
我的代码：
public void startDownload(String apkUrl, String appName){
DownloadManager.Request request = buildRequest(apkUrl, appName);
long lastDownloadId = mDownloadManager.enqueue(request);
Logger.d("In XYZDownloadManager, " + "AppName: " + appName + " with ID: " + lastDownloadId);
}
private DownloadManager.Request buildRequest(String apkUrl, String appName){
Uri uri = Uri.parse(apkUrl);
DownloadManager.Request appDownloadRequest = new DownloadManager.Request(uri);
appDownloadRequest.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI
| DownloadManager.Request.NETWORK_MOBILE)
.setAllowedOverRoaming(false)
.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE)
.setTitle(appName)
.setDescription(WorkspaceApp.getAppContext().getResources().getString(R.string.app_download_description))
.setMimeType("application/vnd.android.package-archive")
.setDestinationInExternalFilesDir(mContext, Environment.DIRECTORY_DOWNLOADS, appName + ".apk");
return appDownloadRequest;
}