How do I set CommandParameter in XAML?

Question

I have the following XAML:

   <dxg:GridControl Name="theGrid" DataSource="{Binding Path=Groupings}">
       <dxg:GridControl.ContextMenu>
           <ContextMenu>
               <MenuItem x:Name="gridprint" Command="{Binding Path=GridPrintCommand}"/>
           </ContextMenu>
       </dxg:GridControl.ContextMenu>
   </dxg:GridControl>

When GridPrintCommand executes, its parameter to the GridPrintCommand.Execute(param) method is null. I want to set the parameter to the grid control. I can do that in the code-behind like this:

gridprint.CommandParameter = theGrid;

This works fine. But I'm trying to set the same thing (CommandParameter) in the XAML, and I just can't get it right! Everything I put results in a BindingExpressionError or a null parameter. What am I missing?

score 11 · Accepted Answer · answered Mar 08 '11 at 18:32

11

Try using this:

<MenuItem x:Name="gridprint"
    CommandParameter="{Binding PlacementTarget, RelativeSource=
         {RelativeSource FindAncestor, AncestorType={x:Type ContextMenu}}}" />

ContextMenus are not part of the WPF's normal VisualTree, so you have to bind using the PlacementTarget to get the object the ContextMenu is attached to

answered Mar 08 '11 at 18:32

Rachel

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Thanks, after three days searching I find that **ContextMenus are not part of the WPF's normal VisualTree, so you have to bind using the PlacementTarget to get the object the ContextMenu is attached to** – ganchito55 Apr 01 '16 at 23:42

score 0 · Answer 2 · answered Mar 08 '11 at 17:17

0

I believe it should be this

<dxg:GridControl Name="theGrid" DataSource="{Binding Path=Groupings}">
  <dxg:GridControl.ContextMenu>
    <ContextMenu>
      <MenuItem x:Name="gridprint"
        Command="{Binding Path=GridPrintCommand}"
        CommandParameter="{Binding ElementName=theGrid}"
      />
    </ContextMenu>
  </dxg:GridControl.ContextMenu>

answered Mar 08 '11 at 17:17

Austin Lamb

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13

If I try that, I get this error message: `System.Windows.Data Error: 4 : Cannot find source for binding with reference 'ElementName=theGrid'. BindingExpression:(no path); DataItem=null; target element is 'MenuItem' (Name='gridprint'); target property is 'CommandParameter' (type 'Object')` – Matt Mar 08 '11 at 17:21
if not mistaken, is something related to the namespaces between the ContextMeny and the GridControl. – Marcote Mar 08 '11 at 17:27

How do I set CommandParameter in XAML?

2 Answers2

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