遠程服務器返回錯誤：（401）我嘗試通過Web客戶端下載文件時發生未授權錯誤

Question

我在Windows窗體應用程序中運行以下代碼：

WebClient client = new WebClient();
WebProxy wp = new WebProxy("http://50.35.125.91:81/");
client.UseDefaultCredentials = true;
wp.Credentials = CredentialCache.DefaultCredentials;
wp.Credentials = new NetworkCredential("matif", "yyy", "xyz");


client.Proxy = wp;
client.DownloadFile("http://50.35.125.91:81/abc/AppUpdate.xml", @"D:\abc.xml");

每次，我得到以下異常

遠程服務器返回錯誤：（401）未經授權。

我知道憑證是有效的，

Answer 1

提供代理和客戶端的憑據：

using (WebClient client = new WebClient())
{
    WebProxy wp = new WebProxy("http://50.35.125.91:81/");
    wp.Credentials = new NetworkCredential("matif", "yyy", "xyz");

    client.UseDefaultCredentials = false;
    client.Credentials = wp.Credentials;
    client.Proxy = wp;
    client.DownloadFile("http://50.35.125.91:81/abc/AppUpdate.xml", @"D:\abc.xml");
}

Answer 2

您正在使用默認憑據。 UseDefaultCredentials應該設置為false而不是true：

client.UseDefaultCredentials = false; 

另外，您根本不需要此行：

wp.Credentials = CredentialCache.DefaultCredentials;

Answer 3

嘗試這個：

using (var Client = new WebClient())
{            
   Client.Credentials = new NetworkCredential("matif", "yyy", "xyz");
   Client.DownloadFile("http://50.35.125.91:81/abc/AppUpdate.xml", @"D:\abc.xml");
}