WebClient.DownloadData不能下载文件？

Question

webClient  请求期间的ex，没有ex的详细信息？对比以前的server 重新设置iis

Answer 1

ex输出的错误就是An exception occurred during a WebClient request

Answer 2

ex输出的错误就是An exception occurred during a WebClient request
FileDownload:Status:UnknownErrorFileDownload:error:An exception occurred during a WebClient request.FileDownload:error:System.Configuration.ConfigurationErrorsException: Error creating the Web Proxy specified in the 'system.net/defaultProxy' configuration section. ---> System.DllNotFoundException: Unable to load DLL 'rasapi32.dll': 动态链接库(DLL)初始化例程失败。 (Exception from HRESULT: 0x8007045A)
   at System.Net.UnsafeNclNativeMethods.RasHelper.RasEnumConnections(RASCONN[] lprasconn, UInt32& lpcb, UInt32& lpcConnections)
   at System.Net.UnsafeNclNativeMethods.RasHelper.GetCurrentConnectoid()
   at System.Net.AutoWebProxyScriptEngine.AutoDetector.Initialize()
   at System.Net.AutoWebProxyScriptEngine.AutoDetector.get_CurrentAutoDetector()
   at System.Net.AutoWebProxyScriptEngine..ctor(WebProxy proxy, Boolean useRegistry)
   at System.Net.WebProxy.UnsafeUpdateFromRegistry()
   at System.Net.WebProxy..ctor(Boolean enableAutoproxy)
   at System.Net.Configuration.DefaultProxySectionInternal..ctor(DefaultProxySection section)
   at System.Net.Configuration.DefaultProxySectionInternal.GetSection()
   --- End of inner exception stack trace ---
   at System.Net.Configuration.DefaultProxySectionInternal.GetSection()
   at System.Net.WebRequest.get_InternalDefaultWebProxy()
   at System.Net.HttpWebRequest..ctor(Uri uri, ServicePoint servicePoint)
   at System.Net.HttpRequestCreator.Create(Uri Uri)
   at System.Net.WebRequest.Create(Uri requestUri, Boolean useUriBase)
   at System.Net.WebRequest.Create(Uri requestUri)
   at System.Net.WebClient.GetWebRequest(Uri address)
   at System.Net.WebClient.DownloadDataInternal(Uri address, WebRequest& request)

Answer 3

是不是需要IIS上设置允许下载.zip格式的文件。右击“默认网站”，属性，http头、MIME类型，新建，...

Answer 4

FileDownload:error:System.Configuration.ConfigurationErrorsException: Error creating the Web Proxy specified in the 'system.net/defaultProxy' configuration section.
创建代理时出错，检查web.config  system.net/defaultProxy配置节
<system.net>
    <defaultProxy useDefaultCredentials="false">
      <proxy usesystemdefault="True" bypassonlocal="True" autoDetect="True" />
    </defaultProxy>
  </system.net>如果有特定的代理服务器，设置
<proxy usesystemdefault="False" bypassonlocal="True" autoDetect="True" proxyaddress="IP:port"  />

Answer 5

终于解决了，web.config里面加
<system.net>
    <defaultProxy useDefaultCredentials="false">
      <proxy usesystemdefault="False"/>
    </defaultProxy>
  </system.net>