c# - WebClient异常，不支持并发I/O操作

Question

我有一个返回 webclient 新实例的静态类

public static class WebAccess
{
    public static WebClient GetWebClient()
    {
        return new WebClient();
    }
}

然后我就用这个类来打页面了

WebAccess.GetWebClient().DownloadString(new Uri("http://" + WLCDomainUrl + ConfigurationManager.AppSettings["urlClearCache"].ToString() + "/?id=" + Request.QueryString["id"] + "&Type=RC"));

我不想捕捉响应

但大多数时候它会抛出异常

WebClient does not support concurrent I/O operations.

Stack Trace:

   at System.Net.WebClient.ClearWebClientState()
   at System.Net.WebClient.DownloadString(Uri address)
   at UpdateCache.ProcessLocationCacheRequest(String locId, Boolean isChain) in 

WebClient does not support concurrent I/O operations.

Stack Trace:

   at System.Net.WebClient.ClearWebClientState()
   at System.Net.WebClient.UploadString(Uri address, String method, String data)
   at System.Net.WebClient.UploadString(String address, String data)
   at CacheClassLibrary.ServerClass.APIServer.Create(String Id, String MobileWLCUrl) in 

有什么帮助吗？我无法想象它是我们的，因为我正在为每个请求提供新的 Web 客户端实例:/

应用程序同时收到多个请求。

Answer 1

试试这个

public static class WebAccess
{
    WebClient instance;
    public static WebClient GetWebClient()
    {
        if (instance == null)
           instance = new WebClient();

        return instance;
    }
}

那么你只有一个 WebClient 类的实例