Question

Working in WPF, writing a custom user control. I am trying to change the background property of the Border element when I change the value of a property of the class. Right now I am working on simply binding it to a DP, though if there is a better way I am open to suggestions.

Here is the XAML for the UserControl

<UserControl x:Class="MyProject.MyControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:js="clr-namespace:MyProject"
             mc:Ignorable="d" 
             x:Name="MyControlRootLayout"
             Background="Transparent"
             d:DesignHeight="300" d:DesignWidth="300" Cursor="Hand">
    <Border x:Name="RootBorder" 
            Background="{Binding Path=CoreBackground, ElementName=MyControlRootLayout}"
    >
    </Border>
</UserControl>

And the code…

public partial class MyControl : UserControl
{
    public static DependencyProperty IsSelectedProperty = DependencyProperty.Register("IsSelected", typeof(bool), typeof(MyControl));
    public static DependencyProperty CoreBackgroundProperty = DependencyProperty.Register("CoreBackground", typeof(Brush), typeof(MyControl));

    public MyControl()
    {
        CoreBackground = new SolidColorBrush(Color.FromArgb(0, 255, 245, 104));

        InitializeComponent();

        Margin = new Thickness(5);
    }

    public Brush CoreBackground
    {
        get { return (Brush)GetValue(CoreBackgroundProperty); }
        set { SetValue(CoreBackgroundProperty, value); }
    }

    public bool IsSelected
    {
        get { return (bool)GetValue(IsSelectedProperty); }
        private set { SetValue(IsSelectedProperty, value); }
    }
}

Instead, the background comes out as transparent.

Answer 1

Your ‘alpha’ channel on the ARGB is 0.
think of the alpha channel as the Opacity… set it to 255 and the Background will appear 🙂