How to use code-behind to create StackPanel -> Border -> Background

Question

I'm trying to set properties of a TreeViewItem -> StackPanel in c# like this question. It seems to make a lot of sense until I get to the part where I try to edit the Background in my Border. Borders have Background objects in them, but for the life of me I can't set a color or anything. It seems to be inconsistent because I can add Content to a Label by simply saying, Content = "Title".

Anyway, this is my code:

public static TreeViewItem childNode = new TreeViewItem() //Child Node 
{
     Header = new StackPanel
     {
         Orientation = Orientation.Horizontal,
         Children =
         {
             new Border {
                 Width = 12,
                 Height = 14,
                 Background = ? //How do I set the background?
             },
             new Label {
                 Content = "Child1"
             }
         }
     }
}; 

PS - I have the same problem when trying to add a BorderBrush

Thank you!

Answer 1

Background property accepts an Brush. Therefore, the code can set the color as follows:

MyLabel.Background = Brushes.Aquamarine;

Or this:

SolidColorBrush myBrush = new SolidColorBrush(Colors.Red);
MyLabel.Background = myBrush;

To set any color, you can use BrushConverter:

BrushConverter MyBrush = new BrushConverter();

MyLabel.Background = (Brush)MyBrush.ConvertFrom("#ABABAB");

Setting the property to the LinearGradientBrush in code:

LinearGradientBrush myBrush = new LinearGradientBrush();

myBrush.GradientStops.Add(new GradientStop(Colors.Yellow, 0.0));
myBrush.GradientStops.Add(new GradientStop(Colors.Green, 0.5));
myBrush.GradientStops.Add(new GradientStop(Colors.Red, 1.0));

MyLabel.Background = myBrush;

For you it would look like this:

private void Window_ContentRendered(object sender, EventArgs e)
{
    TreeViewItem childNode = new TreeViewItem()
    {
        Header = new StackPanel
        {
            Orientation = Orientation.Horizontal,

             Children =
             {
                 new Border
                 {
                     Width = 12,
                     Height = 14,
                     Background = Brushes.Yellow, // Set background here
                 },

                 new Label 
                 {
                     Content = "Child1", 
                     Background = Brushes.Pink, // Set background here
                 }
             }
        }
    };

    MyTreeView.Items.Add(childNode);
}