Question

I have several buttons that does operations on an image. I need to put these buttons on top of the image. Buttons should be images themselves.

• Button should be semi-transparent.

• The image/color should be changed on a click, so that user can know which control is active.

• On hovering over the button, the opacity should increase.

How can I do these. Any guideline on what way to proceed to create a custom control or what controls to use would be very helpful.

Answer 1

If I understand your requirements correctly, I think a ToggleButton should give you what you want.

Basically you need to create one semi-transparent Border for mouse over visual and another semi-transparent Border for unchecked visual. Then in the VisualStateManger, when the MouseOver state is active, you show the MouseOverVisual; when the Unchecked state is active, you show the UncheckedVisual.

I quickly mocked up a style for you in Expression Blend. It’s not perfect but at leasat will give you some ideas. 🙂

    <Style x:Key="SemiTransparentImageToggleButtonStyle" TargetType="ToggleButton">
        <Setter Property="HorizontalAlignment" Value="Center"/>
        <Setter Property="VerticalAlignment" Value="Center"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="ToggleButton">
                    <Grid HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="CommonStates">
                                <VisualState x:Name="Normal"/>
                                <VisualState x:Name="MouseOver">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)" Storyboard.TargetName="MouseOverVisual">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Visible</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                        <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="UncheckedVisual" d:IsOptimized="True"/>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Pressed"/>
                                <VisualState x:Name="Disabled"/>
                            </VisualStateGroup>
                            <VisualStateGroup x:Name="CheckStates">
                                <VisualState x:Name="Checked"/>
                                <VisualState x:Name="Unchecked">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)" Storyboard.TargetName="UncheckedVisual">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Visible</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                            <VisualStateGroup x:Name="FocusStates">
                                <VisualState x:Name="Focused"/>
                                <VisualState x:Name="Unfocused"/>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <ContentPresenter x:Name="contentPresenter" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                        <Border x:Name="MouseOverVisual" Background="White" Opacity="0.5" Visibility="Collapsed" OpacityMask="Black"/>
                        <Border x:Name="UncheckedVisual" Background="White" Opacity="0.7" Visibility="Collapsed"/>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>