This is a migrated thread and some comments may be shown as answers.

GridDropDownColumn error when using AllowAutomaticLoadOnDemand="true"

3 Answers 159 Views

Grid

This is a migrated thread and some comments may be shown as answers.

Josh asked on 09 Mar 2015, 03:09 PM

I reviewed this example: http://demos.telerik.com/aspnet-ajax/grid/examples/columns-rows/columns/column-types/defaultcs.aspx and cannot seem to replicate this in my application.

<telerik:GridDropDownColumn DataField="Item_Id" DataType="System.Int32" FilterControlAltText="Filter Item_Id column" HeaderText="Item" UniqueName="Item_Id" AutoPostBackOnFilter="true" DataSourceID="EntityDataSourceItem" ListValueField="Id" ListTextField="Model" AllowVirtualScrolling="true" ShowMoreResultsBox="true" ItemsPerRequest="10" SortExpression="Item_Id" EmptyListItemText="Select" AllowAutomaticLoadOnDemand="true" DropDownControlType="RadComboBox" >

</telerik:GridDropDownColumn>

<asp:EntityDataSource ID="EntityDataSourceItem" runat="server" ConnectionString="name=autocalEntities" DefaultContainerName="autocalEntities" EnableDelete="True" EnableFlattening="False" EnableInsert="True" EnableUpdate="True" EntitySetName="items"></asp:EntityDataSource

>



Everything populates correctly on load but when I attempt to edit and retrieve a filtered list from the gridview i get the object reference not set to an instance of an object exception. Any idea what I am missing? 



Thanks,

Josh

3 Answers, 1 is accepted

answered on 13 Mar 2015, 12:13 AM

example.png

Certainly,

Here is the mark up attached. I have nothing going on in the code behind. So that shouldn't be necessary. Also I attached a screen shot of exactly what I mean. This only happens when I put the grid in edit mode.

<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>

<telerik:RadGrid ID="RadGrid1" runat="server" DataSourceID="EntityDataSourceAsset" GroupPanelPosition="Top" AllowAutomaticDeletes="True" AllowAutomaticInserts="True" AllowAutomaticUpdates="True" AutoGenerateEditColumn="True">

<MasterTableView AutoGenerateColumns="False" DataKeyNames="Id" DataSourceID="EntityDataSourceAsset">

<Columns>

<telerik:GridBoundColumn DataField="Id" DataType="System.Int32" FilterControlAltText="Filter Id column" HeaderText="Id" ReadOnly="True" SortExpression="Id" UniqueName="Id">

</telerik:GridBoundColumn>

<telerik:GridBoundColumn DataField="CustAsset" FilterControlAltText="Filter CustAsset column" HeaderText="CustAsset" SortExpression="CustAsset" UniqueName="CustAsset">

</telerik:GridBoundColumn>

<telerik:GridBoundColumn DataField="Customer_Id" DataType="System.Int32" FilterControlAltText="Filter Customer_Id column" HeaderText="Customer_Id" SortExpression="Customer_Id" UniqueName="Customer_Id">

</telerik:GridBoundColumn>

<telerik:GridDropDownColumn DataField="Item_Id" ListTextField="MakeModel" ListValueField="Id" DataSourceID="EntityDataSourceMakeModel" AllowAutomaticLoadOnDemand="true" DataType="System.Int32" FilterControlAltText="Filter MakeModel column" HeaderText="Item" SortExpression="MakeModel" UniqueName="Item_Id">

</telerik:GridDropDownColumn>

<telerik:GridBoundColumn DataField="DateCreated" DataType="System.DateTime" FilterControlAltText="Filter DateCreated column" HeaderText="DateCreated" SortExpression="DateCreated" UniqueName="DateCreated">

</telerik:GridBoundColumn>

<telerik:GridBoundColumn DataField="Serial_Number" FilterControlAltText="Filter Serial_Number column" HeaderText="Serial_Number" SortExpression="Serial_Number" UniqueName="Serial_Number">

</telerik:GridBoundColumn>

<telerik:GridBoundColumn DataField="CycleLength" DataType="System.Int32" FilterControlAltText="Filter CycleLength column" HeaderText="CycleLength" SortExpression="CycleLength" UniqueName="CycleLength">

</telerik:GridBoundColumn>

<telerik:GridBoundColumn DataField="LastCalDate" DataType="System.DateTime" FilterControlAltText="Filter LastCalDate column" HeaderText="LastCalDate" SortExpression="LastCalDate" UniqueName="LastCalDate">

</telerik:GridBoundColumn>

<telerik:GridBoundColumn DataField="CalDueDate" DataType="System.DateTime" FilterControlAltText="Filter CalDueDate column" HeaderText="CalDueDate" SortExpression="CalDueDate" UniqueName="CalDueDate">

</telerik:GridBoundColumn>

<telerik:GridBoundColumn DataField="Status" FilterControlAltText="Filter Status column" HeaderText="Status" SortExpression="Status" UniqueName="Status">

</telerik:GridBoundColumn>

<telerik:GridCheckBoxColumn DataField="Standard" DataType="System.Boolean" FilterControlAltText="Filter Standard column" HeaderText="Standard" SortExpression="Standard" UniqueName="Standard">

</telerik:GridCheckBoxColumn>

</Columns>

</MasterTableView>

</telerik:RadGrid>

<asp:EntityDataSource ID="EntityDataSourceAsset" runat="server" ConnectionString="name=autocalEntities" DefaultContainerName="autocalEntities" EnableDelete="True" EnableFlattening="False" EnableInsert="True" EnableUpdate="True" EntitySetName="assets"></asp:EntityDataSource>

<asp:EntityDataSource ID="EntityDataSourceMakeModel" runat="server" ConnectionString="name=autocalEntities" DefaultContainerName="autocalEntities" EnableFlattening="False" EntitySetName="makeandmodels"></asp:EntityDataSource>

answered on 17 Mar 2015, 12:51 PM

Hello Josh,

Can you please try to set the same filed as "DataField" and "ListValueField" like this:

<telerik:GridDropDownColumn DataField="Item_Id" ListTextField="MakeModel" ListValueField="Item_Id" DataSourceID="EntityDataSourceMakeModel" AllowAutomaticLoadOnDemand="true" DataType="System.Int32" FilterControlAltText="Filter MakeModel column" HeaderText="Item" SortExpression="MakeModel" UniqueName="Item_Id">

</telerik:GridDropDownColumn>

and see if this makes any difference.

Regards,
Maria Ilieva
Telerik

Check out the Telerik Platform - the only platform that combines a rich set of UI tools with powerful cloud services to develop web, hybrid and native mobile apps.