XAML, binding Width and Height properties to the s

2019-04-06 23:59发布

问题:

I'm trying to create a reflection effect and it's working great except that I have to hard-code some values. This is my XAML:

 <Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="60"/>
        <RowDefinition />
        <RowDefinition Height="80"/>
    </Grid.RowDefinitions>
    <StackPanel Grid.Row="1" VerticalAlignment="Center">
        <UserControl x:Name="CurrentPresenter" />
        <Border Width="500" Height="200" >
            <Border.Background>
                <VisualBrush Visual="{Binding ElementName=CurrentPresenter}" >
                    <VisualBrush.Transform>
                        <TransformGroup>
                            <ScaleTransform ScaleX="1" ScaleY="-1" CenterX="500" CenterY="99" />
                        </TransformGroup>
                    </VisualBrush.Transform>
                </VisualBrush>
            </Border.Background>
            <Border.OpacityMask>
                    <LinearGradientBrush StartPoint="0,0" EndPoint="0,0.6">
                        <GradientStop Offset="-0.6" Color="Black"></GradientStop>
                        <GradientStop Offset="0.6" Color="Transparent"></GradientStop>
                    </LinearGradientBrush>
                </Border.OpacityMask>
        </Border>
    </StackPanel>
</Grid>

I've tried to replace Border's Width="500" and Height="200" by Width="{Binding ElementName=CurrentPresenter, Path=Width}" and Height="{Binding ElementName=CurrentPresenter, Path=Height}" but it doesn't seem to work.

Wha's wrong with this code?

UPDATE: If I set Width and Height here:

<UserControl x:Name="CurrentPresenter" Height="200" Width="500" />

It works as expected. However it doesn't work if I set those values in the UserControl XAML. Any ideas?

回答1:

Rather than bind to the Height and Width properties of the UserControl, have you tried binding the Height and Width properties of the Border to the ActualHeight and ActualWidth properties of the UserControl?

<Border 
 Width="{Binding ElementName=CurrentPresenter, Path=ActualWidth}"
 Height="{Binding ElementName=CurrentPresenter, Path=ActualHeight}" >


回答2:

change path to ViewportWidth! its work for me