Databinding to Selected Cells collection

[Andy]

Hi,

I have a RadGridView from which I have set up an EventTrigger using the MVVMLight EventToCommand object in order to trap the SelectionChanged event in my ViewModel. This works fine when I pass in the DataGrid as an object to the ViewModel. Below is my Trigger:
 

<i:Interaction.Triggers>
    <i:EventTrigger EventName="SelectionChanged">
        <cmd:EventToCommand  CommandParameter="{Binding ElementName=RadGrid}" Command="{Binding SelectPriotityCommand}"  PassEventArgsToCommand="False"/>
    </i:EventTrigger>
</i:Interaction.Triggers>

 

 

However when I use this pattern I then have to derive the object I am interested in from the SelectedCells collection of the Grid. Also I would rather not access the RadGridView from the ViewModel at all as this is difficult to Unit test. Therefore I would prefer to get a handle on the selected item in the collection from XAML. Should be simple! However if I substitute the CommandParemeter above with the following:

 

Binding ElementName='RadGrid', Path='SelectedCells[0].Item'}

 

Then I get the error

System.Windows.Data Error: Failed to connect to index '0' in object 'Telerik.Windows.Controls.GridView.Selection.CellInfoCollection' (type 'Telerik.Windows.Controls.GridView.Selection.CellInfoCollection'). BindingExpression: Path='SelectedCells[0].Item'

This seems to happen as soon as the page is loaded, am I simply getting this error as the collection is empty? How do I get this to work? I feel I must be missing something rather simple?

Regards,

Andy

[Vlad]

Hi,

Maybe cells collection is empty (you do not have item at index 0) in your case?

Greetings,
Vlad 
the Telerik team