Why doesn't this work?

[Ranger49]

protected override void OnRender(DrawingContext drawCtx)
{
  // Do parent rendering.
  base.OnRender(drawCtx);

  // Add our custom rendering.
  Rect rect = new Rect();
  rect.Width = rectWidth;
  rect.Height = rectHeight;
  drawCtx.DrawRectangle(Brushes.LightBlue, new Pen(Brushes.Blue, 5), rect);

  Random rnd = new Random();
  SolidColorBrush brush = new SolidColorBrush();
  Pen p = new Pen();
  byte red, green, blue;
  Point start = new Point();
  Point end = new Point();

  for (int i = 0; i < 100; i++)
  {
      red = (byte)rnd.Next(0, 255);
      green = (byte)rnd.Next(0, 255);
      blue = (byte)rnd.Next(0, 255);
      brush.Color = Color.FromArgb(255, red, green, blue);
      start.X = rnd.Next(0, 200);
      start.Y = rnd.Next(0, 200);
      end.X = rnd.Next(0, 200);
      end.Y = rnd.Next(0, 200);
      
      drawCtx.DrawLine(new Pen(brush, 3), start, end);
      //Color.FromArgb(255, red, green, blue), 5.0
  }
}

When I try this, I get 100 random lines on my screen like I wanted, but the colors of the lines are all the same instead of a new color for every line, so for some reason my code doesn't change the color of the brush. I wouldn't have a clue what could be the reason for this. The rectangle is drawn fine, I added the code for the lines later myself. Would someone be able to help me? Thankyou, Ranger.

[Gideon Engelberth]

The problem probably comes from the fact that you are using the same brush instance for all the pens you create in the for loop. This:

brush.Color = Color.FromArgb(255, red, green, blue);

will change the color, but you have the same brush each time through the loop. So this:

drawCtx.DrawLine(new Pen(brush, 3), start, end);

will create 100 pens that all use the same brush.

[Ranger49]

Thankyou, It works now. A Brush isn't like a class which you have to distruct first before you can create a new instance. Thanks again, Ranger.