配置上传文件大小
<system.web>
<httpRuntime requestValidationMode="2.0" maxRequestLength="10485760"></httpRuntime>
</system.web>
<system.web>
<httpRuntime requestValidationMode="2.0" maxRequestLength="10485760"></httpRuntime>
</system.web>
上传功能代码是否会发生异常
发生异常就try{}catch{}
在catch中跳转把
http://dotnet.aspx.cc/file/Catch-maxRequestLength-Exceptions-When-Uploading-File-in-ASPNET.aspx