Question

我在OnSelectedIndexChanging上遇到错误

我的aspx文件

<asp:GridView CssClass="table table-striped table-hover" ID="product_all_detail_list" runat="server" OnSelectedIndexChanging="product_detail_list_SelectedIndexChanging" OnSelectedIndexChanged="product_all_detail_list_SelectedIndexChanged" >
       <Columns>
            <asp:CommandField ShowSelectButton="True" />
            <asp:TemplateField HeaderText="ID" Visible="false">
                 <ItemTemplate>
                      <asp:Label ID="lb_id" runat="server" Text='<%#Eval("Id") %>'></asp:Label>
                 </ItemTemplate>
            </asp:TemplateField>                           
       </Columns>
</asp:GridView>

背后的代码

 protected void product_detail_list_SelectedIndexChanging(object sender, GridViewSelectEventArgs e)
{
    Button btn = sender as Button;
 //   GridViewRow row = btn.NamingContainer as GridViewRow;

    GridViewRow row = (GridViewRow)(((Control)sender).NamingContainer);

    all_details.Visible = true;
    Label id = (Label)row.FindControl("lb_id");
    dal.Fillgrid(product_all_detail_list, q);
}

代码是否正确？我也尝试过GridViewRow row = btn.NamingContainer as GridViewRow;

但出现类似Object reference not set to an instance of an object.

的错误

Answer 1

当您调用btn.NamingContainer时，您的btn不在GridView中，它将提供ContentPlaceHolder对象。

将ContentPlaceHolder投射到GridViewRow时会出现异常

尝试使用如下所示的SelectedIndex获取所选行。

GridViewRow row = product_all_detail_list.Rows[product_all_detail_list.SelectedIndex];

有关更多信息，请查看此url

无法将类型为“ System.Web.UI.WebControls.ContentPlaceHolder”的对象转换为类型为“ System.Web.UI.WebControls.GridViewRow”的对象

1 个答案: