Response.End（）之后没有生命 - https://msdn.microsoft.com/en-us/library/system.web.httpresponse.end.aspx [ ^ ]

在您的情况下，唯一发回客户端的是包含excel文件的数据...至于你的按钮，它保持以前的状态......

There is no life after Response.End() - https://msdn.microsoft.com/en-us/library/system.web.httpresponse.end.aspx[^]
In your case the only thing sent back to the client is the data containing the excel file...As for your button, it keeps its previous state...