Question

I am attempting to render some Image objects in a canvas (Layout) on the main form of my application which is called Main. I am using C# and WPF to create the application but am unable to get the images to render from within another class but works without problems in the Main form partial class.

public static void renderStarscape(int density = 200)
    {
        Main main = new Main();
        Random random = new Random();
        for (int x = 0; x < density; x++)
        {
            int starSize = random.Next(1, 10);
            int starOpacity = random.Next(10, 30);
            int starX = random.Next(0, 800);
            int starY = random.Next(0, 500);
            Image Star = new Image();
            Star.Name = (x < 10) ? "star_0" + x : "star_" + x;
            Star.Source = streamImage("star_background.png");
            Star.Height = starSize;
            Star.Width = starSize;
            Star.Opacity = (double)starOpacity / 100;
            main.Layout.Children.Add(Star);
            Canvas.SetLeft(Star, starX);
            Canvas.SetTop(Star, starY);
            Canvas.SetZIndex(Star, 0);
        }
    }

Any help would be great, thanks

Answer 1

You are creating an all new instance of Main in the method which is not same as the one shown on UI.

Instead pass on the instance of the Canvas to the method and draw on that something like this –

public static void renderStarscape( Canvas layout, int density = 200)
{
    // Use layout and remove the Main object initialization from the method.
    layout.Children.Add(Star);
}

The reason its working in partial declaration of class is that you are using the same instance and not creating the new one for Main().