Question

I want to make impossible checking checkbox in WPF (from C# code). Only unchecking would be allowed.

How can I do it?

PS.
Writing event handler on Click event which would immediately uncheck checkbox after checking it is not acceptable.

[edit]
Checkbox should always be enabled, so that user can think that checkbox can be checked. It’s strange but it’s specific programme.

Answer 1

<CheckBox Content="Checkbox"
          IsEnabled="{Binding RelativeSource={RelativeSource Self}, Path=IsChecked}" />

---

Edit after being informed that the checkbox always has to look to be in an checkable state, even when it’s not. Here is a working example:

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero" x:Class="WpfTest.MainWindow"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <ControlTemplate x:Key="DeceptiveCheckbox" TargetType="{x:Type CheckBox}">
            <BulletDecorator Background="Transparent" SnapsToDevicePixels="True">
                <BulletDecorator.Bullet>
                    <Microsoft_Windows_Themes:BulletChrome BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" IsChecked="{TemplateBinding IsChecked}" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderPressed="{TemplateBinding IsPressed}"/>
                </BulletDecorator.Bullet>
                <ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" ContentStringFormat="{TemplateBinding ContentStringFormat}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
            </BulletDecorator>
            <ControlTemplate.Triggers>
                <Trigger Property="HasContent" Value="True">
                    <Setter Property="FocusVisualStyle">
                        <Setter.Value>
                            <Style>
                                <Setter Property="Control.Template">
                                    <Setter.Value>
                                        <ControlTemplate>
                                            <Rectangle Margin="14,0,0,0" SnapsToDevicePixels="True" Stroke="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" StrokeThickness="1" StrokeDashArray="1 2"/>
                                        </ControlTemplate>
                                    </Setter.Value>
                                </Setter>
                            </Style>
                        </Setter.Value>
                    </Setter>
                    <Setter Property="Padding" Value="4,0,0,0"/>
                </Trigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>
    </Window.Resources>
    <Grid>
        <CheckBox Content="CheckBox"  IsEnabled="{Binding IsChecked, RelativeSource={RelativeSource Self}}" Template="{StaticResource DeceptiveCheckbox}" />
    </Grid>
</Window>

The fix was simple. I simply created a copy of the current checkbox template and removed:

<Trigger Property="IsEnabled" Value="False">
    <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>