Problem binding DataGridComboBoxColumn.ItemsSource

Question

I have 3 tables: Item - which is the DataContext - it has a navigation column Group Group - has a navigation column Category.

I want to have in the DataGrid both (Ca

Answer 1

The columns in the datagrid don't have a datacontext, as they are never added to the visual tree. sound a bit weird but have a look at vince's blog, its got a good example of the visual layout. once the grid is drawn the cells have a data context and you can set the combo boxes items source in them using normal bindings (not static resources..)

You can access the combo box items source as such:

<dg:DataGridComboBoxColumn>
   <dg:DataGridComboBoxColumn.EditingElementStyle>
      <Style TargetType="ComboBox">
         <Setter Property="ItemsSource" Value="{Binding Path=MyBindingPath}" />
      </Style>
   </dg:DataGridComboBoxColumn.EditingElementStyle>
</dg:DataGridComboBoxColumn>

Have a look here and also here for some code. You will also need to set the items source for the non edting element as in this post

Answer 2

I was using MVVM and I wanted to bind the ItemSource of the column to a collection of objects in the window data context. I must have tried 10 different ways and nothing worked until I found this answer.

The trick is to define a CollectionViewSource outside the grid and then reference it inside the grid using StaticResource. For example,

<Window.Resources>
    <CollectionViewSource x:Key="ItemsCVS" Source="{Binding MyItems}" />
</Window.Resources>
<!-- ... -->
<DataGrid ItemsSource="{Binding MyRecords}">
    <DataGridComboBoxColumn Header="Column With Predefined Values"
                            ItemsSource="{Binding Source={StaticResource ItemsCVS}}"
                            SelectedValueBinding="{Binding MyItemId}"
                            SelectedValuePath="Id"
                            DisplayMemberPath="StatusCode" />
</DataGrid>