c# - 使用 Xamarin 下载文件

Question

我正在尝试使用 Xamarin 下载文件，但收到错误消息:

An exception occurred during a WebClient request. I thing that the problem is with unhautorization, but I try to download imagen for multiple web, and have the same problem.

代码:

public void getFile() {

    var pathToNewFolder = Android.OS.Environment.ExternalStorageDirectory.AbsolutePath + "/CodeScanner";
    Directory.CreateDirectory(pathToNewFolder);

    try
    {                
        WebClient webClient = new WebClient();
        webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);               
        var folder = Android.OS.Environment.ExternalStorageDirectory.AbsolutePath + "/CodeScanner";
        webClient.DownloadFileAsync(new Uri("http://www.dada-data.net/uploads/image/hausmann_abcd.jpg"), folder);
    }
    catch (Exception ex)
    {
        Console.WriteLine("ERROR:"+ ex.Message);
    }            
}


private void Completed(object sender, AsyncCompletedEventArgs e)
{
    Console.WriteLine("ERROR: "+ e.Error.Message);
} 

错误消息出现在 Console.WriteLine( of Completed 方法中。 首先我创建一个文件夹并尝试将文件保存到其中。

当这个工作时，只需要从本地服务器下载文件。

谢谢。

Answer 1

你只创建了一个文件夹，没有创建下载文件的文件，你可以修改你的代码 webClient.DownloadFileAsync(new Uri("http://www.dada-data.net/uploads/image/hausmann_abcd.jpg"), folder); 例如:

webClient.DownloadFileAsync(new Uri("http://www.dada-data.net/uploads/image/hausmann_abcd.jpg"), folder + "/abc.jpg");