Telerik Treelist NeedDataSource不加载数据

Question

我正在尝试加载treelist，一切正常，但我总是看到“没有记录显示”。

下面是控件：

<telerik:RadTreeList ID="trlProductGroups" runat="server" AllowPaging="true" PageSize="5"
        DataKeyNames="ID" ParentDataKeyNames="PARENT_ID" AutoGenerateColumns="false"
        OnInsertCommand="trlProductGroups_InsertCommand" OnNeedDataSource="trlProductGroups_NeedDataSource"
        OnUpdateCommand="trlProductGroups_UpdateCommand" OnDeleteCommand="trlProductGroups_DeleteCommand">
        <Columns>
            <telerik:TreeListEditCommandColumn UniqueName="InsertCommandColumn" ButtonType="ImageButton"
                HeaderStyle-Width="60px" ItemStyle-HorizontalAlign="Center" />
            <telerik:TreeListEditCommandColumn UniqueName="EditCommandColumn" ButtonType="ImageButton">
                <ItemStyle CssClass="MyImageButton" />
            </telerik:TreeListEditCommandColumn>
            <telerik:TreeListButtonColumn UniqueName="DeleteCommandColumn" Text="Delete" CommandName="Delete"
                ButtonType="ImageButton" />
            <telerik:TreeListBoundColumn DataField="ID" UniqueName="ID" HeaderText="Grup ID"
                ReadOnly="true" />
           <%-- <telerik:TreeListTemplateColumn DataField="GROUP_NAME" UniqueName="GROUP_NAME" HeaderText="Grup Adı">
                <EditItemTemplate>
                    <asp:TextBox ID="txtGroupName" runat="server"></asp:TextBox>
                </EditItemTemplate>
            </telerik:TreeListTemplateColumn>--%>
            <telerik:TreeListBoundColumn DataField="GROUP_NAME" UniqueName="GROUP_NAME" HeaderText="Grup Adı" />
            <telerik:TreeListBoundColumn DataField="PARENT_ID" UniqueName="PARENT_ID" HeaderText="Ana Grup ID"
                ReadOnly="true" />
        </Columns>
    </telerik:RadTreeList>

下面是NeedDataSource代码：

 protected void trlProductGroups_NeedDataSource(object sender, TreeListNeedDataSourceEventArgs e)
        {

            WebAppTest.Objects.ProductGroups pGroups = new WebAppTest.Objects.ProductGroups();
            DataTable dt = pGroups.SelectData(null, string.Empty);
            trlProductGroups.DataSource = dt;
        }

我可以在DataTable中看到数据，但是treelist不会加载数据。我是不是搞错了？

谢谢

Answer 1

它需要是，在数据源中至少有一个数据的id_parent值为空。也许这会有帮助。