CODEWITHSUNDEEP
silverlightrounded-corners
K Mehta
K Mehta

Reputation: 10553

Rounded rectangle in Silverlight

I'm trying to create a rectangle in Silverlight where the corners are rounded. However, I do not explicitly specify the width and the height of the rectangle, which means it adapts to the size of the Grid which contains it (the size of the grid depends on the screen resolution amongst other things, and is not known before hand).

I'd like the RadiusX and RadiusY properties to be percentages of the rectangle's width and height respectively. What would be the cleanest way of doing this? Is there a XAML-only way of doing it (without resorting to code-behind)?

Upvotes: 0

Views: 999

Answers (2)

K Mehta
K Mehta

Reputation: 10553

While Justin King's answer works if the Width and Height are known before hand, it doesn't work if they're not set, and the parent control dynamically lays the rectangle out. Unfortunately, in Silverlight, you cannot use Binding with Converters on ActualWidth and ActualHeight, as they are calculated properties. What this means is that when ActualWidth and ActualHeight change, a property changed event is not raised internally, so the binding wouldn't propagate the changes to the source.

Essentially, at this point, the only option is to subscribe to the LayoutUpdated event and calculate and set the RadiusX and RadiusY properties in code-behind.

Upvotes: 0

Justin King
Justin King

Reputation: 1428

Two files below to download I used for testing this http://dl.dropbox.com/u/8679840/SilverlightApplication1.zip

Best way for reuse is to create a Type converter like

<Grid x:Name="LayoutRoot" Background="White">
    <Rectangle x:Name="rectangle" 
    Width="200" Height="200"
    RadiusX="{Binding Width, ElementName=rectangle, Converter={StaticResource myConverter}, ConverterParameter=.1}" 
    RadiusY="{Binding Height, ElementName=rectangle, Converter={StaticResource myConverter}, ConverterParameter=.1}"
    />
</Grid>

and the code behind

namespace SilverlightApplication1
{
      public class PercentConverter : IValueConverter 
    { 
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 
        { 
            return System.Convert.ToDouble(value) * System.Convert.ToDouble(parameter); 
        } 

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 
        { 
            throw new NotImplementedException(); 
        } 
    }
}

Upvotes: 2

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