C# 所有标题都有500个错误

我只是想ping谷歌或一些网站，看看我是否可以让这个代码工作。我是C#的新手，所以我不知道为什么这是错误的。我有什么遗漏吗

 System.Net.WebClient myWebClient = new System.Net.WebClient();

 myWebClient.Proxy = new System.Net.WebProxy("--mywebproxy--");

 myWebClient.Headers["User-Agent"] = "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.2.6) Gecko/20100625 Firefox/3.6.6 (.NET CLR 3.5.30729)"; 
 myWebClient.Headers["Accept"] = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"; 
 myWebClient.Headers["Accept-Language"] = "en-us,en;q=0.5"; 
 myWebClient.Headers["Accept-Encoding"] = "    gzip,deflate"; 
 myWebClient.Headers["Accept-Charset"] = "ISO-8859-1,utf-8;q=0.7,*;q=0.7"; 

 myWebClient.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;


 myWebClient.DownloadData("http://www.google.com");

---

我希望您使用的是实际的URI

像

如果仍然无法工作，请安装所有IIS并重试

你知道，整个代码都是

        var myWebClient = new System.Net.WebClient { Proxy = new System.Net.WebProxy("http://127.0.0.1") };


        myWebClient.Headers["User-Agent"] = "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.2.6) Gecko/20100625 Firefox/3.6.6 (.NET CLR 3.5.30729)";
        myWebClient.Headers["Accept"] = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
        myWebClient.Headers["Accept-Language"] = "en-us,en;q=0.5";
        myWebClient.Headers["Accept-Encoding"] = "    gzip,deflate";
        myWebClient.Headers["Accept-Charset"] = "ISO-8859-1,utf-8;q=0.7,*;q=0.7";

        myWebClient.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;


        var x = myWebClient.DownloadData("http://www.google.com");

---

在Try{}Catch{}处包装代码，并报告实际出现的错误。。

        var myWebClient = new System.Net.WebClient { Proxy = new System.Net.WebProxy("http://127.0.0.1") };


        myWebClient.Headers["User-Agent"] = "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.2.6) Gecko/20100625 Firefox/3.6.6 (.NET CLR 3.5.30729)";
        myWebClient.Headers["Accept"] = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
        myWebClient.Headers["Accept-Language"] = "en-us,en;q=0.5";
        myWebClient.Headers["Accept-Encoding"] = "    gzip,deflate";
        myWebClient.Headers["Accept-Charset"] = "ISO-8859-1,utf-8;q=0.7,*;q=0.7";

        myWebClient.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;


        var x = myWebClient.DownloadData("http://www.google.com");