如何在DataBound事件和插入事件中从Telerik RadGrid的UserControl中获取值

Question

我使用的是telerik grid，这里我把RadGrid的UserControl放在了GridTemplateColumn里面，类似这样

    <telerik:GridTemplateColumn UniqueName="HardCoded" HeaderText="HardCoded" AllowFiltering="true"
                DataField="AccountDesc">
                <ItemTemplate>
                    <asp:Label ID="HardCoded" runat="server" Text='<%# Bind("HardCoded") %>'></asp:Label>
                </ItemTemplate>
                <EditItemTemplate>
                    <UserCtrl:UserCtrl runat="server" ID="lbl" />
                </EditItemTemplate>
                <InsertItemTemplate>
                  <UserCtrl:UserCtrl runat="server" ID="lbl" />                        
                </InsertItemTemplate>
                </telerik:GridTemplateColumn>

这里

这是我的UserControl组合代码

<telerik:RadComboBox runat="server" ID="HardCoded" >
    <Items>
        <telerik:RadComboBoxItem Value="1" Text="Member" Selected="true" />
        <telerik:RadComboBoxItem Value="2" Text="Employee" />
        <telerik:RadComboBoxItem Value="3" Text="All" />
    </Items>
</telerik:RadComboBox>

在数据绑定事件中，如果我按下网格上的编辑按钮，我只想设置选定的值。以下是我的DataBound事件代码

  protected void RadGrid1_OnItemDataBound(object sender, Telerik.Web.UI.GridItemEventArgs e)
        {
            if (e.Item.IsInEditMode)
            {
                   GridEditableItem editableItem = e.Item as GridEditableItem;
                    RadComboBox HardCoded = editableItem["HardCoded"].Controls[0] as RadComboBox;
                  // I've also tried 
 RadComboBox HardCoded = (RadComboBox)e.Item.FindControl("HardCoded");//it also didn't work

            }
    }

在这里，我总是得到object reference not set to a instance of a object的错误，因为它无法找到我的UserControl RadCombo

类似地，如果我想在插入事件中获得值，我无法找到我的组合框，这是我的代码

    protected void RadGrid1_InsertCommand(object sender, Telerik.Web.UI.GridCommandEventArgs e)
    {
  string HardCoded = ((RadComboBox)ii["HardCoded"].FindControl("HardCoded")).SelectedValue;
   }

未设置对象引用的类似异常

Answer 1

在OnItemDataBound事件处理程序中使用GridEditFormItem，而不是使用GridEditableItem，如下所示：

protected void RadGrid1_OnItemDataBound(object sender, GridItemEventArgs e)
{
    if (e.Item is GridEditFormItem && e.Item.IsInEditMode)//the grid is about to Edit.
    {
        GridEditFormItem item = (GridEditFormItem)e.Item;
        RadComboBox combo = (RadComboBox)item.FindControl("HardCoded");
        combo.SelectedValue = "Something";
    }
}