Editing gridviewcomboboxcolumn

[josephine shirley]

Hi,

I am having a scenario that I need to enter a new value to the field or select a existing value in the combo box. On change of the cell selection I need to insert or update the value in the database.

The issue is

Im able to enter new value to the combobox ,But when I selecting the adjacent cell of the same edited row after editing, the entered value disappears.But When I selecting a cell other than the edited row  then Im able to get the changes as required.


Thank you in advance

[Pavel Pavlov]

Hi josephine shirley,

I am attaching a small sample application which I believe resembles your scenario .
The relevant code is in the mainpage.xaml and mainpage.xaml.cs

*It is a Silverlight application , but exactly the same approach may be used in WPF as RadGridView for SL and RadGridView for WPF share a common API and codebase. If you find troubles with the project adn need it converted for WPF , just let me know.

In case this is not exactly what you are looking for , I will be glad to have a look at your code and check what is wrong.

Best wishes,
Pavel Pavlov
the Telerik team

[josephine shirley]

Hi

Thanks for the reply.But my scenario is somewhat different from the one you've sent. PLease see the following

<telerikGrid:RadGridView x:Name="lstFieldDetails"   Grid.Row="1"   ShowGroupPanel="False"  SelectionMode="Single"   IsFilteringAllowed="False"  AutoGenerateColumns="false" CellEditEnded="lstFieldDetails_CellEditEnded">

                        <telerikGrid:RadGridView.Columns>

                                <telerikGrid:GridViewComboBoxColumn  IsComboBoxEditable="True" x:Name="cmbCategoryName" DataMemberBinding ="{Binding DBDCategoryID}" DisplayMemberPath = "Category Name" SelectedValueMemberPath = "Category ID" Header="Category Name"  />

                                <telerikGrid:GridViewDataColumn IsReadOnly="True"  IsEnabled="False"  x:Name="gvcDBDCategoryID" Width="Auto" IsVisible="false" Header="Category ID"  DataMemberBinding="{Binding DBDCategoryID}"/>

                                <telerikGrid:GridViewDataColumn  IsReadOnly="True"   IsEnabled="False"  x:Name="gvcFieldDescription" Width="Auto" Header="Field Description"  DataMemberBinding="{Binding FieldDescription}"/>

                            </telerikGrid:RadGridView.Columns>

  </telerikGrid:RadGridView>

    private void lstFieldDetails_CellEditEnded(object sender, Telerik.Windows.Controls.GridViewCellEditEndedEventArgs e)
        {


                string sCategoryName = ((Telerik.Windows.Controls.RadComboBox)e.EditingElement).Text;
 //updating db using new value
 //repopulating both the grid and combobox 
                string layerTableID = ((DataRowView)lstLayerDetails.SelectedItem)["LayerTableID"].ToString();
                if (!string.IsNullOrEmpty(layerTableID))
                {
                    DataTable dt;
                    dbParam = new DbParameter[1];
                    dbParam[0] = Trimble.UFS.Database.Helper.Parameter;
                    dbParam[0].ParameterName = "@LayerTableID";
                    dbParam[0].Value = layerTableID;
                    dt = new DataTable();
                    dt = Trimble.UFS.Database.Helper.ExecuteDT(_schemaName, "sp_ListAllFieldDetails", dbParam);
                    lstFieldDetails.ItemsSource = dt.DefaultView;
                    ///To repopulate the Comboboxcolumn

                    dt = new DataTable();
                    dt = Trimble.UFS.Database.Helper.ExecuteDT(_schemaName, "sp_ListAllCategoryIDs", null);
                    cmbCategoryName.ItemsSource = dt.DefaultView;
                }
            }

        }

The above scenario is very similar to the example given by the telerik documnetation (see following link).

http://www.telerik.com/help/wpf/radgridview-columns-column-types-combobox-column.html

We are having relationship between the radgridvew itemsource and the comboboxitem source.As per my requirement I need to have editing option for comboboxcolumn.In this case in the cell edit end event after changing the database I tried to repopulate both radgridview and combox altogether and leads to the following error.

After the event execution it leads to the following error:

{"Object reference not set to an instance of an object."}

 The related stack trace is as follows.

   at Telerik.Windows.Controls.GridView.GridViewCell.RaiseCellEditEndedEvent(GridViewEditAction editAction) in c:\Builds\WPF_Scrum\Release_WPF_2010_Q2\Sources\Development\Controls\GridView\GridView\GridView\Cells\GridViewCell.cs:line 910
   at Telerik.Windows.Controls.GridView.GridViewDataControl.PerformCellEditEnded(GridViewCell currentCell) in c:\Builds\WPF_Scrum\Release_WPF_2010_Q2\Sources\Development\Controls\GridView\GridView\GridView\GridViewDataControl.Editing.cs:line 98
   at Telerik.Windows.Controls.GridView.GridViewDataControl.CommitCellEdit(GridViewCell currentCell, Boolean isLeavingRow) in c:\Builds\WPF_Scrum\Release_WPF_2010_Q2\Sources\Development\Controls\GridView\GridView\GridView\GridViewDataControl.Editing.cs:line 65
   at Telerik.Windows.Controls.GridView.GridViewDataControl.OnCurrentCellInfoChanging(GridViewCellInfo oldCell, GridViewCellInfo newCell) in c:\Builds\WPF_Scrum\Release_WPF_2010_Q2\Sources\Development\Controls\GridView\GridView\GridView\GridViewDataControl.cs:line 787
   at Telerik.Windows.Controls.GridView.GridViewDataControl.set_CurrentCellInfo(GridViewCellInfo value) in c:\Builds\WPF_Scrum\Release_WPF_2010_Q2\Sources\Development\Controls\GridView\GridView\GridView\GridViewDataControl.cs:line 729
   at Telerik.Windows.Controls.GridView.GridViewDataControl.BeginEdit(GridViewCell gridViewCell, RoutedEventArgs editingEventArgs) in c:\Builds\WPF_Scrum\Release_WPF_2010_Q2\Sources\Development\Controls\GridView\GridView\GridView\GridViewDataControl.Editing.cs:line 467
   at Telerik.Windows.Controls.GridView.GridViewDataControl.BeginEdit(GridViewCell gridViewCell) in c:\Builds\WPF_Scrum\Release_WPF_2010_Q2\Sources\Development\Controls\GridView\GridView\GridView\GridViewDataControl.Editing.cs:line 462
   at Telerik.Windows.Controls.GridView.GridViewDataControl.OnCellMouseDown(GridViewCell cell) in c:\Builds\WPF_Scrum\Release_WPF_2010_Q2\Sources\Development\Controls\GridView\GridView\GridView\GridViewDataControl.Editing.cs:line 268
   at Telerik.Windows.Controls.GridView.GridViewCell.OnMouseLeftButtonDown(MouseButtonEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF_2010_Q2\Sources\Development\Controls\GridView\GridView\GridView\Cells\GridViewCell.cs:line 383
   at System.Windows.UIElement.OnMouseLeftButtonDownThunk(Object sender, MouseButtonEventArgs e)
   at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
   at System.Windows.UIElement.OnMouseDownThunk(Object sender, MouseButtonEventArgs e)
   at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
   at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
   at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
   at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.Run()
   at System.Windows.Application.RunDispatcher(Object ignore)
   at System.Windows.Application.RunInternal(Window window)
   at System.Windows.Application.Run(Window window)
   at System.Windows.Application.Run()
   at Shell.App.Main() in C:\Shire\Shire\Toolbox\Shell\obj\x86\Debug\App.g.cs:line 0

[josephine shirley]

Can you let me know whether you able to replicate the error?

[Pavel Pavlov]

Hello josephine shirley,

Can you please try execute the code which repopulates the grid and the column with Dispatcher.BeginInvoke() . In case this does not help we will look for another solution.


All the best,
Pavel Pavlov
the Telerik team

[josephine shirley]

Ive used the Dispatcher.BeginInvoke() also.But it is not solving my problem.

[Nedyalko Nikolov]

Hello josephine shirley,

Could you send me a sample project that simulates this issue, since I cannot reproduce the described error? After a detailed review of the stack trace I have a guess what could cause the null reference exception, unfortunately I cannot confirm that without a project.
Thank you in advance.

P.S. You have to open a separate support ticket in order to be able to attach a project. If you cannot open a support ticket send me a link to any public location.

Regards,
Nedyalko Nikolov
the Telerik team