Question

Trigger on an Inner property

<Button BorderBrush="Black" BorderThickness="2" x:Name="TimeButton" ClickMode="Press" Click="SetTime_Click" Height="26" HorizontalAlignment="Left" Margin="15, 0, 0, 0" Style="{StaticResource ImageButtonStyle}" ToolTip="Set Time" Width="26">
    <Button.Background>
        <ImageBrush x:Name="TimeImageBrush" ImageSource="/YCS;component/Images/Clock.png" Stretch="Uniform" TileMode="None" />                                        
    </Button.Background>  
</Button>

I need to make a trigger to set the ImageBrush in the Button.Background property to something different according to a boolean named HasHours which I can bind easily from my itemssource, any one knows how I can achieve this, I could not find any examples linking to this property….

I tried something like this

<Button.Triggers>
    <DataTrigger Binding="{Binding HasHours}" Value="false">
        <Setter TargetName="TimeImageBrush" Property="ImageSource" Value="/YCS;component/Images/ClockRed.png"/>
    </DataTrigger>
</Button.Triggers>

but it gives me this error:

Cannot find the static member ‘ImageSourceProperty’ on the type ‘ContentPresenter’.

Any help is much appreciated

Answer 1

This is perhaps not exactly an answer to your question.

First, i guess you won’t be able to add a DataTrigger to the Triggers collection, since that only supports EventTriggers.

But, you could define the DataTrigger in the Button’s Style. Here, instead of setting the ImageBrush’s ImageSource property, simply set a new ImageBrush as Background.

<Button ...>
    <Button.Style>
        <Style TargetType="Button">
            <Style.Triggers>
                <DataTrigger Binding="{Binding HasHours}" Value="False">
                    <Setter Property="Background">
                        <Setter.Value>
                            <ImageBrush ImageSource="/YCS;component/Images/ClockRed.png"/>
                        </Setter.Value>
                    </Setter>
                </DataTrigger>
            </Style.Triggers>                    
        </Style>
    </Button.Style>
</Button>