How to bind a ICommand into a Button out of DataContext? - wpf

Question

i have a Button into a DataGrid with a DataContext (KeyValuePair).
I want to implementing a Command into this Button.
But if i use the Command="{Binding CommandoTest}" it didnt work.
I tested the ICommand into a Grid without DataContext and it works well.
<DataGrid DataContext="{Binding PersonList.Keys}">
<DataGrid.Columns>
<DataGridTemplateColumn>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Grid>
<Button Command="{Binding CommandoTest}" Content="CommandoTest"></Button>
</Grid>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
The Command Code:
Public ReadOnly Property CommandoTest As ICommand
Get
Return CommandTest_exp
End Get
End Property
Public Sub CommandTest_exp()
MessageBox.Show("Test", "Test")
End Sub

Answer 1

I imagine that the DataGrid is inside of some element whose DataContext is the one with the CommandoTest property on it.
If that is the case, using the example of a Grid as the parent, you could use:
<Grid x:Name="parent_grid">
<DataGrid DataContext="{Binding PersonList.Keys}">
<DataGrid.Columns>
<DataGridTemplateColumn>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Grid>
<Button Command="{Binding DataContext.CommandoTest, ElementName=parent_grid}" Content="CommandoTest"></Button>
</Grid>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
</Grid>
Another approach, in which you don't have to name any controls, would be (this wouldn't work for the Grid in the previous example, as it would first find the Grid which is the parent of your Button, so I've added another parent element of type Border):
<Border>
<Grid>
<DataGrid DataContext="{Binding PersonList.Keys}">
<DataGrid.Columns>
<DataGridTemplateColumn>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Grid>
<Button Command="{Binding DataContext.CommandoTest, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Border}}}" Content="CommandoTest"></Button>
</Grid>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Border>