如何阅读ASP。NET内部服务器错误描述?

Behold the code:

看代码:

using (var client = new WebClient())
{
    try
    {
        var bytesReceived = client.UploadData("https://localhost", bytesToPost);
        var response = client.Encoding.GetString(bytesReceived);
    }
    catch (Exception ex)
    {
    }
}
using (var client = n