Hi,

it took me a while to find out the actual behavior of the GridView, but I think I got and now and would just like to point out a misleading example and ask if I've misunderstood something.

When attaching to the RadGridView.SelectedCellsChanged-event, I get the following behavior:

1.  When a complete row was selected and the grid is sorted/grouped, I receive a SelectedCellsChanged-event with the newly added cells (all cells of the row). However, the GridViewSelectedCellsChangedEventArgs do not contain the removed cells. Is this by design because the removed GridViewCellInfo-instances are no longer part of the updated grid?

2.  When only single cells were selected and the grid is sorted/grouped, the selection of these cells seem to be cleared. However, I do not receive a SelectedCellsChanged-event. This is okay for me, as I can still listen to

• the RadGridView.Sorted-event 
• the RadGridView.Grouped-event

and clean up my ViewModel-CellSelection there. But this leads to the misleading example "Grid View - Selection" in the WPF Controls Examples suite. Here, the SelectedCellsBindingBehavior.cs only listens to the SelectedCellsChanged-event, which results in cells still being listed in the "Selected cells:"-Listbox of the example after a sorting operation, although they are no longer selected.

Greetings,

Andree

Hi,

If a button is placed in a RadMenu that causes navigation (in a Frame/Page setup), then the button is not getting focus and hence any Bindings that are present where the focus is are not executed before navigation takes place.  I see https://www.telerik.com/forums/radmenu-problem-404186d89499 and https://www.telerik.com/forums/i-think-i-found-a-nasty-bug which look like the same problem.  Is there any solution for this problem aside from not using RadMenu that will work for the focus being in any control?  I note that in Silverlight RadMenu does not have this problem. 

Hi all 

I have a ListBox and its has Items to be Displayed. Additional i have added 

 <telerik:ListBoxDragDrop.Behavior> // for dragging operation
<telerik:ListBoxDragDropBehavior AllowReorder="True" telerik:TouchManager.DragStartTrigger="TapHoldAndMove" />
</telerik:ListBoxDragDrop.Behavior>
            
<telerik:ListBoxDragDrop.DragVisualProvider> //// for dragging Visual operation
<telerik:ScreenshotDragVisualProvider />
</telerik:ListBoxDragDrop.DragVisualProvider>

Any idea to Restrict the Dragging-Visual within the parent windows bounds.

Thanks In Advance

Hi,

I am using the RadSplashScreen and I would like to allow the following actions:

- Set splashscreen as not topmost

- Allow to move the splashscreen (no resize, or close, just move)

Thank you for your help

 I know grid performance has been discussed many times, but I could not derive a solution so far from those posts.

The scenario is very simple, we have to show 20 items in a grid. The data paging responsibility is ours, the grid sees only 20 rows.

When the ItemsSource changes, 1-2 sec is needed for the grid to display the new results.

The performance is bad regardless of Virtualization settings (and 20 rows do not need virtualization at all naturally).

Fixed Height and With do not help, I think this is not the usual infinite height MeasureOverride issue.

I have attached DotTrace and VS profiler traces, so you can see the problematic paths.
The profiler pinpoints MeasureOverride at the surface. Most posts about grid performance revolve around this.
However, when we dig deeper we see creating each datagrid row took about 50ms.
For 20 rows this is 1sec. This explains the perceived delay.
The attached dottrace images show that LoadContent is called many hundred times, this is what actually eats the time.

Now, it is your turn to explain what I can do to avoid this big performance overhead.

Tell me if you need more profiling data from me.

Thanks,
Zsolt

I have a RadTabControl and I want to enable the drop-down button "WhenNeeded" so that users can easily access the buttons in the tab control. I have three templates for the tab items (RadTabItem) which means I should have 3 templates as well for the drop-down buttons that appear in the drop-down list. 

There is a field called ItemDropDownContentTemplateSelector in RadTabControl and I created a template selector class like so:

    public class DropDownDisplayModeTemplateSelector: DataTemplateSelector
    {
        public override DataTemplate
            SelectTemplate(object item, DependencyObject container)
        {
            try
            {
                FrameworkElement element = container as FrameworkElement;
                Console.WriteLine("DropDownDisplayModeTemplateSelector: " + element.GetType().Name);
                if (element != null && item != null && item is TabItem)
                {
                    TabItem tabItem = item as TabItem;

                    switch (tabItem.TabItemStyle)
                    {
                        case TabItemStyle.Title:
                            return element.FindResource("TitleDropDownModeDataTemplate") as DataTemplate;

                        case TabItemStyle.Button:
                            return element.FindResource("ButtonDropDownModeDataTemplate") as DataTemplate;

                        case TabItemStyle.GroupOfButtons:
                            return element.FindResource("GroupOfButtonsDropDownModeDataTemplate") as DataTemplate;

                        default:
                            return element.FindResource("ButtonDropDownModeDataTemplate") as DataTemplate;
                    }
                }
                else
                    return null;
            }
            catch(Exception ex)
            {
                Console.WriteLine(ex.Message);
                return null;
            }
        }
    }

However, finding the DataTemplates with element.FindResource() method doesn't work because the container element is of type "DropDownMenuItem" which of course is not the element where my data templates are defined.

I have them defined in the top level Grid element like so:

<Grid>
        <Grid.Resources>
            <ResourceDictionary>

                <DataTemplate x:Key="TitleDropDownModeDataTemplate">
                    <TextBlock
                        HorizontalAlignment="Left"
                            VerticalAlignment="Center"
                            Margin="4"
                            Grid.Column="1"
                            Text="TitleDropDownModeDataTemplate" />
                </DataTemplate>

                <DataTemplate x:Key="ButtonDropDownModeDataTemplate">
                    <TextBlock
                        HorizontalAlignment="Left"
                            VerticalAlignment="Center"
                            Margin="4"
                            Grid.Column="1"
                            Text="ButtonDropDownModeDataTemplate" />
                </DataTemplate>

                <DataTemplate x:Key="GroupOfButtonsDropDownModeDataTemplate">
                    <TextBlock
                        HorizontalAlignment="Left"
                            VerticalAlignment="Center"
                            Margin="4"
                            Grid.Column="1"
                            Text="GroupOfButtonsDropDownModeDataTemplate" />
                </DataTemplate>

                <models:DropDownDisplayModeTemplateSelector x:Key="myDropDownDisplayModeTemplateSelector"/>
            </ResourceDictionary>
        </Grid.Resources>
        
        <telerik:RadTabControl

           ItemsSource="{Binding TabItems}"

           ItemDropDownContentTemplateSelector="{StaticResource myDropDownDisplayModeTemplateSelector}"
            DropDownDisplayMode="WhenNeeded">
</Grid>

In this case what should I do, hack the way top to the Grid's resources or I have done something wrong in defining my drop-down template selector?

Hi there,

very simple scenario - we have a RadRichTextBox and want to show a placeholder (ghost) when there is no content in it.
Same behavior like WatermarkTextBox

Found no simple solution for this... or I have overseen something..

Thank you, Andi

Hi,

I want to be able to receive the file and/or set the file for the radSpreadsheet.CommandDescriptors.SaveFile.Command  command. It appears that no event can be handled before or after the command is executed.

Thanks