Null reference exception when setting the DataSource of a ChildGridViewTemplate

[Ami Bar]

Hi,

I am using RadControls for WinForms Q3 2009 SP1

I created two UserControls each one has a RadGridView in it. i.e. AListControl and BListControl.
Each RadGridView is bounded to a DataSource which list objects of type A and B.
When I use the controls separately (as I should) it works fine.

Now I try to use the RadGridView of object B as a ChildGridViewTemplate of A.
To avoid recreating the whole grid definition I use the following in AListControl constructor:

public AListControl()
{
   InitializeComponent();

   // Create dummy BListControl
   BListControl bListControl = new BListControl();

   // Add the B's MasterGridViewTemplate to A as a ChildGridViewTemplates
   this.radGridViewA.MasterGridViewTemplate.ChildGridViewTemplates.Add(
      bListControl.radGridViewB.MasterGridViewTemplate);

   // Add the relation
   GridViewRelation relation = new GridViewRelation(this.radGridViewA.MasterGridViewTemplate);
   relation.ChildTemplate = bListControl.radGridViewB.MasterGridViewTemplate;
   relation.RelationName = "A2B";
   relation.ParentColumnNames.Add("Id");
   relation.ChildColumnNames.Add("B.AId");
   this.radGridViewA.Relations.Add(relation);
}

I also added a menu item in the context menu that sets the DataSource of bListControl.radGridViewB.MasterGridViewTemplate.
When I set the DataSource the application fails with the exception "Object reference not set to an instance of an object."

This is the callstack I got:

     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridTraverser.IsRowVisible(Telerik.WinControls.UI.GridViewRowInfo rowInfo) + 0x32 bytes   
     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridTraverser.MoveForward() + 0x95 bytes   
     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridTableElement.UpdateScrollbars(bool resetValue) + 0x165 bytes   
     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridTableElement.Update_OrderChanged(Telerik.WinControls.UI.GridUINotifyAction action, Telerik.WinControls.UI.GridViewRowInfo[] rowInfos) + 0x12c bytes   
     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridTableElement.UpdateCore(Telerik.WinControls.UI.GridUINotifyAction action, Telerik.WinControls.UI.GridViewRowInfo[] rowInfos) + 0x74 bytes   
     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridViewTemplate.UpdateUI(Telerik.WinControls.UI.GridUINotifyAction action = SortingChanged, Telerik.WinControls.UI.GridViewRowInfo[] rowInfos) + 0x33f bytes   
     Telerik.WinControls.GridView.dll!Telerik.WinControls.Data.DataAccessComponent.InitializeSorting() + 0x109 bytes   
     Telerik.WinControls.GridView.dll!Telerik.WinControls.Data.DataAccessComponent.InitDataGrid() + 0x14e bytes   
     Telerik.WinControls.GridView.dll!Telerik.WinControls.Data.DataAccessComponent.Bind(object dataSource, string dataMember) + 0x32c bytes   
     Telerik.WinControls.GridView.dll!Telerik.WinControls.Data.DataAccessComponent.DataSource.set(object value) + 0x65 bytes   
>   InspectSims.exe!Inspector.AListControl.ShowBsClicked(object sender = {Telerik.WinControls.UI.RadMenuItem}, System.EventArgs e = {System.EventArgs}) Line 62 + 0x2b bytes   C#

Can you tell me if this is the correct way to do this, or if there is another way to do this ?

Regards,
Ami

[Stefan]

Hello Ami Bar,

Thank you for writing. 

This exception is a result of setting the MasterGridViewTemplate from one grid to another, which is forbidden. Each grid has its own and only one MasterGridViewTemplate (this is why its called master). Please consider the following link, you might find it helpful.

 
Best wishes,
Stefan
the Telerik team