Can I put the textbox in the datatemplate directly?

See more:

.NET

WPF

Say I have the code.

<telerik:GridViewDataColumn Header="Contact">
    <telerik:GridViewDataColumn.CellTemplate>
         <DataTemplate>
               <TextBox Text="{Binding SomeText, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}" />
         </DataTemplate>
   </telerik:GridViewDataColumn.CellTemplate>
</telerik:GridViewDataColumn>

The thing is the validation is not firing. However if I put the TextBox into StackPanel.

<telerik:GridViewDataColumn Header="Contact">
    <telerik:GridViewDataColumn.CellTemplate>
         <DataTemplate>
             <StackPanel>
               <TextBox Text="{Binding SomeText, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}" />
             </StackPanel>
         </DataTemplate>
   </telerik:GridViewDataColumn.CellTemplate>
</telerik:GridViewDataColumn>

Then it works, I don't know why? Sorry for the silly question. I just want to understand the concept well.

What I have tried:

A StackPanel contains a collection of UIElement objects, which are in the Children property.