[Solved] Overlaying a RadComboBox over a grid cell

[Terry]

Hi:

I have a RadGridView that lists properties.  The names of the properties are in column 1 and the values of the properties are in column 2.

Most of the property values are text and can be edited in the normal way, but a few of them require a selection via a RadComboBox.  How can I position a RadComboBox over the cell in the BeginningEdit event?

Thanks,

Terry

[Maya]

Hi Terry,

You may take a look at this forum thread for a reference and a sample project. 

Regards,
Maya
the Telerik team

[Terry]

Thanks, Maya, this works great as far as it goes.  One issue, though is setting the combobox to the current underlying PropertyValue when the edit starts.

Thanks,

Terry

[Terry]

As I have received no response to this, I might need to clarify.

Using the SL_RadGridView_Template sample code, the initial selected value is 1.  When I click on the cell and enter edit mode, the combobox has no selected value.  it should be initialized to 1.  

Also if I select one of the choices, this is correctly reflected in the underlying textblock, but when I go back and edit a second time, I am given a combobox with no item selected again.  It should be initialized to the underlying current value.

How do I accomplish this?  Even though the binding mode is two way, it looks like the binding is only working one way.

Thanks,

Terry

[Maya]

Hi Terry,

You may try to use a RadComboBox instead of a regular ComboBox:

<DataTemplate x:Key="EnumPropertyValueEditTemplate">
    <telerik:RadComboBox
    SelectedValue="{Binding PropertyValue, Mode=TwoWay}"
   ItemsSource="{Binding EnumNames}"   />
</DataTemplate>

 

Greetings,
Maya
the Telerik team

[Terry]

That solves the initialization problem.

Thanks for your help, Maya!

[Terry]

It turns out this technique is causing another problem for me.  Previously, I was using the grid's BeginningEdit event to determine whether the cell was editable and the CellValidating event to validate the results and store them away.  After adding a template selector, this still works for cells where I use the enumerator with a RadComboBox, but it does not work for the non-enumeration cells which use a TextBox for editing.  I'm uncertain how I can hook in events for text cells to allow/disallow editing and for validating and saving results after the edit.

Stated another way, cell events ARE NOT working when a textbox template is selected, but they ARE working when a RadComboBox enumerator is selected.

Can you help me with this?

Thanks,

Terry

Here's the grid XAML:

<radGridView:RadGridView x:Name="gvProperties" VerticalAlignment="Stretch" AutoGenerateColumns="False"
    ScrollViewer.HorizontalScrollBarVisibility="Auto" ShowColumnHeaders="False" SelectionMode="Single" CanUserSelect="True"
    GridLinesVisibility="Both"  ShowGroupPanel="False"
    ScrollViewer.VerticalScrollBarVisibility="Auto" ScrollMode="Deferred"  RowIndicatorVisibility="Collapsed"
    CanUserDeleteRows="False" CanUserInsertRows="False" RowLoaded="gvProperties_RowLoaded"
    BeginningEdit="gvProperties_BeginningEdit"  CellEditEnded="gvProperties_CellEditEnded"
    SelectionChanged="gvProperties_SelectionChanged" CellValidating="gvProperties_CellValidating" >
    <radGridView:RadGridView.Columns>
        <radGridView:GridViewDataColumn UniqueName="PropAlias" Width="1*"/>
        <radGridView:GridViewDataColumn UniqueName="PropValue" Width="1*"
            CellTemplateSelector="{StaticResource PropertyValueTemplateSelector}"
            CellEditTemplateSelector="{StaticResource PropertyValueEditTemplateSelector}" />
    </radGridView:RadGridView.Columns>
</radGridView:RadGridView>

and here's the template XAML:

<DataTemplate x:Key="TextPropertyValueEditTemplate">
    <TextBox Text="{Binding PropValue, Mode=TwoWay}"/>
</DataTemplate>

<DataTemplate x:Key="TextPropertyValueDisplayTemplate">
    <TextBlock Text="{Binding PropValue}" />
</DataTemplate>


<DataTemplate x:Key="EnumPropertyValueEditTemplate">
            <radinput:RadComboBox
            SelectedValue="{Binding PropValue, Mode=TwoWay}"
            ItemsSource="{Binding EnumNames}"   />
</DataTemplate>

<local:PropertyValueDataTemplateSelector x:Key="PropertyValueEditTemplateSelector"
         TextTemplate="{StaticResource TextPropertyValueEditTemplate}"
         EnumTemplate="{StaticResource EnumPropertyValueEditTemplate}"  />

<local:PropertyValueDataTemplateSelector x:Key="PropertyValueTemplateSelector"
        TextTemplate="{StaticResource TextPropertyValueEditTemplate}"
        EnumTemplate="{StaticResource TextPropertyValueDisplayTemplate}"/>

and here's the C#:

using System.Windows;
using Telerik.Windows.Controls;

namespace WireframeEditor
{
    public class PropertyValueDataTemplateSelector : DataTemplateSelector
    {
        public override System.Windows.DataTemplate SelectTemplate(object item, System.Windows.DependencyObject container)
        {
            if ( ( (MainPage.ElementProperty) item ).PropName == "Type" )
            {
                return this.EnumTemplate;
            }
            else
            {
                return this.TextTemplate;
            }
        }

        public DataTemplate TextTemplate { get; set; }
        public DataTemplate EnumTemplate { get; set; }
    }
}

[Maya]

Hi Terry,

You need to make a slight change to the definition of the  PropertyValueTemplateSelector:

<local:PropertyValueDataTemplateSelector x:Key="PropertyValueTemplateSelector" 
              TextTemplate="{StaticResource TextPropertyValueDisplayTemplate}"                                                EnumTemplate="{StaticResource TextPropertyValueDisplayTemplate}"/>

All the best,
Maya
the Telerik team

[Terry]

With your change, everything is working perfectly. 

Thanks for your quick response!

Terry