DataGridComboBoxColumn绑定

Question

I have seen a few posts on here with people getting confused on how to bind to a DataGridComboBoxColumn,

I have

<DataGridComboBoxColumn SelectedItemBinding="{Binding Collection}"  DisplayMemberPath="Name" Header="Name" Width="70">

which didnt work..

So I used

<DataGridComboBoxColumn ItemBinding="{Binding Collection}" DisplayMemberPath="Name"> Header="Name" Width="70">

Which again didn't work, why is binding to a datagridcombo different to a original combo box.

<ComboBox ItemsSource="{Binding Collection}" DisplayMemberPath="Name" HorizontalAlignment="Left">

which does work

What is the correct method of binding to a combo box inside a DataGrid?

---Edit---

I might have found the problem, I have a DataGrid binding to a ItemSource, however, I want the ComboBoxColumn to be bounded to a different Itemsource, is this possible?

Cheers

Answer 1

You need to bind to ItemsSource property. Set it in EditingElementStyle .

<DataGridComboBoxColumn>
    <DataGridComboBoxColumn.EditingElementStyle>
        <Style TargetType="ComboBox">
            <Setter Property="ItemsSource" Value="{Binding Collection}"/>
            <Setter Property="DisplayMemberPath" Value="Name"/>
        </Style>
    </DataGridComboBoxColumn.EditingElementStyle>
</DataGridComboBoxColumn>

---

In case you want ItemsSource to bind to collection which is outside of DataGrid underlying source object, you can do that as well.

Say you have collection AnotherCollection residing in ViewModel of Window/UserControl, you can bind with it using RelativeSource markup extension.

Also, you have to set SelectedItemBinding to the property where you want to set the value selected from ComboBox and declare same style under ElementStyle of DataGridComboBoxColumn. Suppose property name is Name to which you want to bind.

<DataGridComboBoxColumn SelectedItemBinding="{Binding Name}">
    <DataGridComboBoxColumn.EditingElementStyle>
        <Style TargetType="ComboBox">
            <Setter Property="ItemsSource"
                    Value="{Binding DataContext.AnotherCollection,
                               RelativeSource={RelativeSource Mode=FindAncestor, 
                                                         AncestorType=Window}}"/>
            <Setter Property="DisplayMemberPath" Value="Name"/>
        </Style>
    </DataGridComboBoxColumn.EditingElementStyle>
    <DataGridComboBoxColumn.ElementStyle>
        <Style TargetType="ComboBox">
            <Setter Property="ItemsSource"
                    Value="{Binding DataContext.AnotherCollection,
                              RelativeSource={RelativeSource Mode=FindAncestor, 
                                                         AncestorType=Window}}"/>
            <Setter Property="DisplayMemberPath" Value="Name"/>
        </Style>
    </DataGridComboBoxColumn.ElementStyle>
</DataGridComboBoxColumn>