(System.Web.UI.HtmlControls.HtmlIframe) is not compatible with the type of control (System.Web.UI.Ht

從Framework 2.0-3.5 更新到Framework 4.5時遇到 Iframe 轉換為伺服器控件遇到不相容問題

錯誤資訊：

     but its type (System.Web.UI.HtmlControls.HtmlIframe) is not compatible with the type of control (System.Web.UI.HtmlControls.HtmlGenericControl).

原因分析：

     在.NET Framework 4.5 中， iframe的HTML 标記不再向HtmlGenericControl類的映射，需映射到System.Web.UI.HtmlControls.HtmlIframe

參考文檔：

https://briancaos.wordpress.com/2013/08/07/system-web-ui-htmlcontrols-htmliframe-is-not-compatible-with-the-type-of-control-system-web-ui-htmlcontrols-htmlgenericcontrol/

https://support.microsoft.com/zh-cn/help/941824/error-message-when-you-build-an-asp.net-2.0-web-application-in-visual