Question

I have a WPF form with a DataGrid. This DG contains a DataGridTemplateColumn that contains a ComboBox. When I click on the new row of the DG and selected a value from the Combobox and then tab to the next column, the selected value does not stay visible in the combobox column.

However, when I tab back, the correct value shows in the combobox.

How do I keep the selected value showing in the combobox column when I tab off the column?

Here is my comboxbox column xaml:

<DataGridTemplateColumn Header="Type" Width="160">
<DataGridTemplateColumn.CellTemplate>
    <DataTemplate>
        <TextBlock Text="{Binding LocationType.Description, Mode=TwoWay}"/>
    </DataTemplate>
</DataGridTemplateColumn.CellTemplate>

<DataGridTemplateColumn.CellEditingTemplate>
    <DataTemplate>
        <StackPanel Orientation="Horizontal">
            <ComboBox Name="cboAddrtype"
                      ItemTemplate="{StaticResource dtAddrType}" IsSynchronizedWithCurrentItem="True"
                      ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}, AncestorLevel=1}, Path=DataContext.LocationTypesObject, Mode=OneTime}"
                      SelectedItem="{Binding Path=SelectedLocationType, UpdateSourceTrigger=PropertyChanged, Mode=OneWay}"
                      SelectedValue="{Binding Path=LocationTypeKey, Mode=TwoWay}"
                      SelectedValuePath="InternalKey"
                      Width="100" />

        </StackPanel>

    </DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>

Answer 1

In CellTemplate you’re binding LocationType.Description and in CellEditingTemplate you’re binding SelectedLocationType and LocationTypeKey. I’m not sure that your binding from ComboBox won’t somehow affect LocationType.Description.

Furthermore, SelectedLocationType and LocationTypeKey are not in the context of DataTemplate. You should add a Source binding property to get your ViewModel.