CODEWITHSUNDEEP
wpfxamlmvvmbindingdatatemplate
dotNET
dotNET

Reputation: 35400

Modifying TabControl's header

So I'm adding my views directly to the TabControl's Items collection at runtime (instead of creating TabItems around them and addings those TabItems to TabControl). The views expose a property (wrapper around a ViewModel property of the same name) named HasChanges that I want to bind to TabItem's Header to show a Asterisk (*) sign to identify tabs with unsaved changes, just like VS does. I have already tried using DataTemplates but am having trouble accessing the view object in the DataTemplate. What's the correct way of doing this? Here's one of my several attempts:

<TabControl.ItemTemplate>
    <DataTemplate DataType="UserControl">
        <StackPanel Orientation="Horizontal" Margin="0" Height="22">
            <TextBlock VerticalAlignment="Center" Text="{Binding HeaderText, RelativeSource={RelativeSource AncestorType=UserControl}}" />
            <TextBlock Text="*" Visibility="{Binding HasChanges, RelativeSource={RelativeSource Mode=TemplatedParent}, Converter={StaticResource B2VConverter}}" />
        </StackPanel>
    </DataTemplate>
</TabControl.ItemTemplate>

Note that I'm trying two different binding methods for the two TextBlocks, none of which is working. My views inherit from UserControl and expose properties HasChanges and HeaderText.

Upvotes: 3

Views: 4603

Answers (1)

dotNET
dotNET

Reputation: 35400

OK. I solved it myself. For anyone else trying to implement a VS-like Close button and unsaved changes asterisk, here's the template:

<TabControl.ItemContainerStyle>
    <Style TargetType="{x:Type TabItem}">
        <Setter Property="HeaderTemplate" >
            <Setter.Value>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal" Margin="0" Height="22">
                        <TextBlock VerticalAlignment="Center" Text="{Binding RelativeSource={RelativeSource AncestorType=TabItem}, Path=Content.HeaderText}" />
                        <TextBlock Text=" *" ToolTip="Has unsaved changes" Visibility="{Binding Content.DataContext.HasChanges, RelativeSource={RelativeSource AncestorType=TabItem}, Converter={StaticResource B2VConverter}}" />
                        <Button Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}" Width="18" Height="18" 
                                Margin="6,0,0,0" Padding="0" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" HorizontalAlignment="Center" 
                                Command="{Binding DataContext.TabClosingCommand, RelativeSource={RelativeSource AncestorType={x:Type Window}}}"
                                CommandParameter="{Binding RelativeSource={RelativeSource AncestorType=UserControl}}"
                                VerticalAlignment="Center" Focusable="False">
                            <Grid Margin="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                                <Line StrokeThickness="3" StrokeStartLineCap="Round"  StrokeEndLineCap="Round" Stroke="Gray" X1="1" Y1="1" X2="9" Y2="9" HorizontalAlignment="Center" VerticalAlignment="Center" />
                                <Line StrokeThickness="3" StrokeStartLineCap="Round" StrokeEndLineCap="Round" Stroke="Gray" X1="1" Y1="9" X2="9" Y2="1" HorizontalAlignment="Center" VerticalAlignment="Center" />
                            </Grid>
                        </Button>
                    </StackPanel>
                </DataTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</TabControl.ItemContainerStyle>

Results in an elegant drawing-based button with a flat-look. Your View must implement Boolean HasChanges and HeaderText properties, plus you need to define a BooleanToVisibilityConverter in your resources section, named B2VConverter.

Upvotes: 6

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