windows xp .net framework 4.0 HttpWebRequest 報The underlying connection was closed,基礎鏈接已關閉

windows xp .net framework 4.0 HttpWebRequest 報The underlying connection was closed,基礎鏈接已關閉,錯誤的解決方法

在 HttpWebRequest 請求的上方加入如下代碼

ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;