How do I create a WPF Rounded Corner container? - wpf

Question

We are creating an XBAP application that we need to have rounded corners in various locations in a single page and we would like to have a WPF Rounded Corner container to place a bunch of other elements within. Does anyone have some suggestions or sample code on how we can best accomplish this? Either with styles on a or with creating a custom control?

Answer 1

You don't need a custom control, just put your container in a border element:
<Border BorderBrush="#FF000000" BorderThickness="1" CornerRadius="8">
<Grid/>
</Border>
You can replace the <Grid/> with any of the layout containers...

Answer 2

I know that this isn't an answer to the initial question ... but you often want to clip the inner content of that rounded corner border you just created.
Chris Cavanagh has come up with an excellent way to do just this.
I have tried a couple different approaches to this ... and I think this one rocks.
Here is the xaml below:
<Page
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Background="Black"
>
<!-- Rounded yellow border -->
<Border
HorizontalAlignment="Center"
VerticalAlignment="Center"
BorderBrush="Yellow"
BorderThickness="3"
CornerRadius="10"
Padding="2"
>
<Grid>
<!-- Rounded mask (stretches to fill Grid) -->
<Border
Name="mask"
Background="White"
CornerRadius="7"
/>
<!-- Main content container -->
<StackPanel>
<!-- Use a VisualBrush of 'mask' as the opacity mask -->
<StackPanel.OpacityMask>
<VisualBrush Visual="{Binding ElementName=mask}"/>
</StackPanel.OpacityMask>
<!-- Any content -->
<Image Source="http://chriscavanagh.files.wordpress.com/2006/12/chriss-blog-banner.jpg"/>
<Rectangle
Height="50"
Fill="Red"/>
<Rectangle
Height="50"
Fill="White"/>
<Rectangle
Height="50"
Fill="Blue"/>
</StackPanel>
</Grid>
</Border>
</Page>

Answer 3

I just had to do this myself, so I thought I would post another answer here.
Here is another way to create a rounded corner border and clip its inner content. This is the straightforward way by using the Clip property. It's nice if you want to avoid a VisualBrush.
The xaml:
<Border
Width="200"
Height="25"
CornerRadius="11"
Background="#FF919194"
>
<Border.Clip>
<RectangleGeometry
RadiusX="{Binding CornerRadius.TopLeft, RelativeSource={RelativeSource AncestorType={x:Type Border}}}"
RadiusY="{Binding RadiusX, RelativeSource={RelativeSource Self}}"
>
<RectangleGeometry.Rect>
<MultiBinding
Converter="{StaticResource widthAndHeightToRectConverter}"
>
<Binding
Path="ActualWidth"
RelativeSource="{RelativeSource AncestorType={x:Type Border}}"
/>
<Binding
Path="ActualHeight"
RelativeSource="{RelativeSource AncestorType={x:Type Border}}"
/>
</MultiBinding>
</RectangleGeometry.Rect>
</RectangleGeometry>
</Border.Clip>
<Rectangle
Width="100"
Height="100"
Fill="Blue"
HorizontalAlignment="Left"
VerticalAlignment="Center"
/>
</Border>
The code for the converter:
public class WidthAndHeightToRectConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
double width = (double)values[0];
double height = (double)values[1];
return new Rect(0, 0, width, height);
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}

Answer 4

VB.Net code based implementation of kobusb's Border control solution. I used it to populate a ListBox of Button controls. The Button controls are created from MEF extensions. Each extension uses MEF's ExportMetaData attribute for a Description of the extension. The extensions are VisiFire charting objects. The user pushes a button, selected from the list of buttons, to execute the desired chart.
' Create a ListBox of Buttons, one button for each MEF charting component.
For Each c As Lazy(Of ICharts, IDictionary(Of String, Object)) In ext.ChartDescriptions
Dim brdr As New Border
brdr.BorderBrush = Brushes.Black
brdr.BorderThickness = New Thickness(2, 2, 2, 2)
brdr.CornerRadius = New CornerRadius(8, 8, 8, 8)
Dim btn As New Button
AddHandler btn.Click, AddressOf GenericButtonClick
brdr.Child = btn
brdr.Background = btn.Background
btn.Margin = brdr.BorderThickness
btn.Width = ChartsLBx.ActualWidth - 22
btn.BorderThickness = New Thickness(0, 0, 0, 0)
btn.Height = 22
btn.Content = c.Metadata("Description")
btn.Tag = c
btn.ToolTip = "Push button to see " & c.Metadata("Description").ToString & " chart"
Dim lbi As New ListBoxItem
lbi.Content = brdr
ChartsLBx.Items.Add(lbi)
Next
Public Event Click As RoutedEventHandler
Private Sub GenericButtonClick(sender As Object, e As RoutedEventArgs)
Dim btn As Button = DirectCast(sender, Button)
Dim c As Lazy(Of ICharts, IDictionary(Of String, Object)) = DirectCast(btn.Tag, Lazy(Of ICharts, IDictionary(Of String, Object)))
Dim w As Window = DirectCast(c.Value, Window)
Dim cc As ICharts = DirectCast(c.Value, ICharts)
c.Value.CreateChart()
w.Show()
End Sub
<System.ComponentModel.Composition.Export(GetType(ICharts))> _
<System.ComponentModel.Composition.ExportMetadata("Description", "Data vs. Time")> _
Public Class DataTimeChart
Implements ICharts
Public Sub CreateChart() Implements ICharts.CreateChart
End Sub
End Class
Public Interface ICharts
Sub CreateChart()
End Interface
Public Class Extensibility
Public Sub New()
Dim catalog As New AggregateCatalog()
catalog.Catalogs.Add(New AssemblyCatalog(GetType(Extensibility).Assembly))
'Create the CompositionContainer with the parts in the catalog
ChartContainer = New CompositionContainer(catalog)
Try
ChartContainer.ComposeParts(Me)
Catch ex As Exception
Console.WriteLine(ex.ToString)
End Try
End Sub
' must use Lazy otherwise instantiation of Window will hold open app. Otherwise must specify Shutdown Mode of "Shutdown on Main Window".
<ImportMany()> _
Public Property ChartDescriptions As IEnumerable(Of Lazy(Of ICharts, IDictionary(Of String, Object)))
End Class

Answer 5

If you're trying to put a button in a rounded-rectangle border, you should check out msdn's example. I found this by googling for images of the problem (instead of text). Their bulky outer rectangle is (thankfully) easy to remove.
Note that you will have to redefine the button's behavior (since you've changed the ControlTemplate). That is, you will need to define the button's behavior when clicked using a Trigger tag (Property="IsPressed" Value="true") in the ControlTemplate.Triggers tag. Hope this saves someone else the time I lost :)