Question

So, on my DataGrid, I have the below Style, set up, Binding the ReadOnly and Reordering variables to be triggered using the MultiDataTrigger, I know it works because it greys out and sets values to read-only. The only problem is that if for the ComboBoxs created with the DataGridTemplateColumn don’t have their IsReadOnly value being set. How can I get this working? I don’t know how I would go about finding how the Template Column should be bound.

DataGrid Style (which is wrapped in the <DataGrid></DataGrid> tag)

 <DataGrid.Style>
            <Style TargetType="{x:Type DataGrid}">
                <Style.Triggers>
                    <MultiDataTrigger>
                        <MultiDataTrigger.Conditions>
                            <Condition Binding="{Binding ReadOnly}" Value="True"/>
                            <Condition Binding="{Binding Reordering}" Value="False"/>
                        </MultiDataTrigger.Conditions>
                        <MultiDataTrigger.Setters>
                            <Setter Property="IsReadOnly" Value="True" />
                            <Setter Property="Foreground" Value="Gray" />
                        </MultiDataTrigger.Setters>
                    </MultiDataTrigger>
                    <MultiDataTrigger>
                        <MultiDataTrigger.Conditions>
                            <Condition Binding="{Binding ReadOnly}" Value="True"/>
                            <Condition Binding="{Binding Reordering}" Value="True"/>
                        </MultiDataTrigger.Conditions>
                        <MultiDataTrigger.Setters>
                            <Setter Property="IsReadOnly" Value="True" />
                        </MultiDataTrigger.Setters>
                    </MultiDataTrigger>
                    <MultiDataTrigger>
                        <MultiDataTrigger.Conditions>
                            <Condition Binding="{Binding ReadOnly}" Value="False"/>
                        </MultiDataTrigger.Conditions>
                        <MultiDataTrigger.Setters>
                            <Setter Property="IsReadOnly" Value="False" />
                        </MultiDataTrigger.Setters>
                    </MultiDataTrigger>
                </Style.Triggers>
            </Style>
        </DataGrid.Style>

Code for creating a a DataGridTemplateColumn

 DataTemplate comboDisplayTemplate = new DataTemplate();
 FrameworkElementFactory comboDisplayElement = new FrameworkElementFactory(typeof(ComboBox));
 Binding comboDisplayBinding = new Binding(f.ColumnName) { UpdateSourceTrigger = UpdateSourceTrigger.LostFocus };
 comboDisplayElement.SetBinding(ComboBox.SelectedValueProperty, comboDisplayBinding);
 comboDisplayElement.SetValue(ComboBox.DisplayMemberPathProperty, "Value");
 comboDisplayElement.SetValue(ComboBox.SelectedValuePathProperty, "Key");
 Binding comboDisplayListBinding = new Binding(f.ColumnName + "List");
 comboDisplayElement.SetValue(ComboBox.ItemsSourceProperty, comboDisplayListBinding);
 comboDisplayTemplate.VisualTree = comboDisplayElement;
 templateColumn.CellTemplate = comboDisplayTemplate;

  DataGridTemplateColumn templateColumn = new DataGridTemplateColumn() {
      Header = f.ShortDisplay,
 };

 DataTemplate comboboxTemplate = new DataTemplate();
 FrameworkElementFactory comboboxElement = new FrameworkElementFactory(typeof(ComboBox));
 Binding comboboxBinding = new Binding(f.ColumnName) { UpdateSourceTrigger = UpdateSourceTrigger.LostFocus };
 comboboxElement.SetBinding(ComboBox.SelectedValueProperty, comboboxBinding);
 comboboxElement.SetValue(ComboBox.DisplayMemberPathProperty, "Value");
 comboboxElement.SetValue(ComboBox.SelectedValuePathProperty, "Key");
 Binding comboboxListBinding = new Binding(f.ColumnName + "List");
 comboboxElement.SetValue(ComboBox.ItemsSourceProperty, comboboxListBinding);
 comboboxTemplate.VisualTree = comboboxElement;
 templateColumn.CellEditingTemplate = comboboxTemplate;

Answer 1

The IsReadOnly property is used for Controls to allow/disallow users to change the underlying text of a Control, however ComboBoxes do not have an underlying text to change by default. I had to use the IsHitTestVisible property of UIElement, from MSDN -> Gets or sets a value that declares whether this element can possibly be returned as a hit test result from some portion of its rendered content.

  <Setter Property="IsHitTestVisible" Value="False" />