GridView里删除会报错？
GridView里删除会报错，

Must declare the scalar variable "@SnoGonggao".
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异常详细信息: System.Data.SqlClient.SqlException: Must declare the scalar variable "@SnoGonggao".

我的SnoGonggao是表的主键，但是DeleteParameters里已经定义了Name="SnoGonggao"了啊，怎么回事啊？

<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:GDSSConnectionString %>"
SelectCommand="SELECT [SnoGonggao], [datetime], [gonggao] FROM [gonggao]"
DeleteCommand="DELETE FROM [gonggao] WHERE [SnoGonggao] = @SnoGonggao" InsertCommand="INSERT INTO [gonggao] ([datetime], [gonggao]) VALUES (@datetime, @gonggao)"
UpdateCommand="UPDATE [gonggao] SET [datetime] = @datetime, [gonggao] = @gonggao WHERE [SnoGonggao] = @SnoGonggao">
<DeleteParameters>
<asp:Parameter Name="SnoGonggao" Type="Int32" />
</DeleteParameters>

------解决方案--------------------
GridView里加 DataKeyNames="SnoGonggao"