There's an issue with the RadMultiColumnComboBox in that the inner text field is left aligned so if the user doesn't click exactly in the text box, then they can't type anything.

In the attached image, I set the border of the inner textbox to red just for a visual aid. If the user clicks anywhere inside the red border, then the field gets focus and they can type and everything works as expected. However, if they're not focused on that field and they try to click to the right of the red border, it does nothing and to the user, it feels buggy.

I tried setting the horizontal alignment of the text box to stretch, but that had no effect. Is there a fix for this?

I'm having an issue with the RadMultiColumnComboBox where it accepts returns, so it grows the field when it shouldn't. I tried this but it had no effect:

private void MultiColumnComboBox_Loaded(object sender, RoutedEventArgs e)
{
    var textBox = MultiColumnComboBox.FindChildByType<TextBox>();
            
    if (textBox != null)
    {
        textBox.AcceptsReturn = false;
        textBox.AcceptsTab = false;
    }
}

I've been working with the Telerik WPF controls for the last couple of months and appreciating them.

<rant>

However, I have a major gripe as well:  most of the examples are FAR too complex.  Here's a perfect example.  I'm trying to get a ComboBox to work with a GridView.  There is an example that does pretty much exactly what I want at https://github.com/telerik/xaml-sdk/tree/master/ComboBox/DropDownWithHeaders.  However,

1. A simple clone from the repository won't run.  That seems fundamental to me.  When I look into it, the problem is themes.  A simple example should not even include themes!  I would suggest a proper example would allow me to clone and run, with nothing else on my machine but Visual Studio.
2. When I look into the actual example, it is anything but simple!  The control template is 155 lines of code!?!?!  How do I sort through that quickly and figure out what I need and don't need?  I don't need all kinds of animation or fancy styles.  For the purposes of learning the controls, I need the absolute minimum to make it work!

There is also an example of this at https://www.telerik.com/forums/radcombobox-with-radgridview, but it suffers from the same problems.

This kind of thing seriously makes me ponder going back to our old controls provider.

</rant>

Now, can someone please provide me with a simple example of a ComboBox that uses a GridView for the drop-down?

Of course perhaps I'm using the wrong control.  Maybe I should be using the MultiColumnComboBox, but the end results shown in the examples make it look nothing like a traditional ComboBox.  (Again, that may be owing to a lack of a good, simple example.)

Help?

Hi,

I'm using a RadMultiColumnComboBox and can't seem to be able to set the validation error template to Tooltip using:

telerik:ValidationErrorTemplateHelper.DisplayMode="ToolTip"

It always set the validation message on the right of the control, and in my case it's being clipped by the windows limits.

This usually works great on all other controls.

Thank you for your help

I have the following XAML code:

<telerik:RadMultiColumnComboBox 
    VerticalAlignment="Top" 
    Width="250" 
    DisplayMemberPath="Name" 
    IsReadOnly="True" 
    SelectionMode="Single" 
    SelectionBoxesVisibility="Hidden" 
    CloseDropDownAfterSelectionInput="True"                   
    DropDownWidth="320"
    SelectedItem="{Binding SelectedMandant}">
    <telerik:RadMultiColumnComboBox.ItemsSourceProvider>
        <telerik:GridViewItemsSourceProvider ItemsSource="{Binding MandantCollection}" AutoGenerateColumns="False" RowIndicatorVisibility="Hidden"> 
            <telerik:GridViewItemsSourceProvider.Columns>
                <telerik:GridViewDataColumn Header="Mandant" DataMemberBinding="{Binding Path=Name}"/>
                <telerik:GridViewDataColumn 
                    Header="Letzter Abschluss" 
                    DataMemberBinding="{Binding Path=FibuAbschluss}" 
                    DataFormatString="{} {0:dd.MM.yyyy}" 
                    TextAlignment="Center" 
                    HeaderTextAlignment="Center"/>
            </telerik:GridViewItemsSourceProvider.Columns>
        </telerik:GridViewItemsSourceProvider>
    </telerik:RadMultiColumnComboBox.ItemsSourceProvider>
    <telerik:EventToCommandBehavior.EventBindings>
        <telerik:EventBinding EventName="SelectionChanged" Command="{Binding SelectedMandantChangedCmd}" RaiseOnHandledEvents="True" PassEventArgsToCommand="True"/>
    </telerik:EventToCommandBehavior.EventBindings>
</telerik:RadMultiColumnComboBox>

Now everything works fine beside that the first time when the UI is rendered, the RadMultiColumnComboBox Input does not show the current selected item.

I set the SelectedItem in the constructor of my view model:

private Mandant? _selectedMandant;
public Mandant? SelectedMandant
{
    get => _selectedMandant;
    set
    {
        _selectedMandant = value;
        OnPropertyChanged();
    }
}

public KontoViewModel(CommonDbContext commonDbContext, StruebyWinBContext winBContext)
 {
     ......
     if(MandantCollection.Count > 0)
     {
         SelectedMandant = MandantCollection[0];
         ......
     }
     .......
 }

I see that the SelectedMandat has a value and also it works fine after i select another item, then the item shows.

But the first time after loading, the RadMultiColumnComboBox Input does not show any value, its empty.

It should show the selected item that i set in the constructor of my view model.

Can anyone help me here, thanks

Hello,

I am having an issue with RadMultiColumnComboBox. I am having to set to a large width for them to not line wrap. When I select an item it is doing this:

How can I prevent it from doing this? The width is more than twice the size of the largest element, and it is set to single select so there is no reason to wrap the text.

Hi Team,

I joined the project attaching Telerik.2020.2.617.45 version.

but I can download only 2023.xx version.

So How can i download 2020.2.617.45 version.

Hello,

I am dealing with a minor bug on my pages that have a hidden panel that I show when adding new items. It shows the selected item, but also includes the text afterwards. It only happens when the dropdown visibility is collapsed. When I am populating the dropdowns I have tried setting  AutoCompleteProvider.SearchText = string.Empty and AutoCompleteProvider.MatchText = string.Empty and setting the panel to visible and then populating the value, but I cannot figure out how to clear out the text. What is a good work around for this bug. 

I have a RadMultiColumnComboBox with AutoCompleteMode="Search". If I type "asdf" into the combo box, close the dropdown without actually selecting an item, and then refresh the page I want to clear "asdf", but I cannot figure out how to clear this text. I have tried setting the selected Item to null, setting AutoCompleteProvider.SearchText to an empty string, and setting the selected index to -1. 

What am I doing wrong?