private void ImageDrawingRepeat(ImageDrawing id) { Action <int> iAction = (i) => { for (int j = 0; j < 100; j++) { id.DrawCircle(Color.Lime, j, i, 1, false); id.DrawSquare(Color.Lime, j, i, 1, false); id.DrawCross(Color.Lime, j, i, 1, false); id.DrawPlus(Color.Lime, j, i, 1, false); id.DrawCircle(Color.Lime, j, i, 8, true); id.DrawSquare(Color.Lime, j, i, 8, true); id.DrawCross(Color.Lime, j, i, 8, true); id.DrawPlus(Color.Lime, j, i, 8, true); } }; if (chkDrawingRepeatParallel.Checked) { Parallel.For(0, 100, iAction); } else { for (int i = 0; i < 100; i++) { iAction(i); } } }