I have draw vertical line, two line have one pixel distance.
Line 1 (9,10)----(9,200)
Line 2 (11,10)----(11,200)
Clip Region---- Rectangle(10,10,1,190)
I set the one pixel width clip rectangle in graphics, just like the following code.
public void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
Region vRegion = new Region(new Rectangle(new Point(10,10),new Size(1,300)));
Region oldRegion = e.Graphics.Clip;
Pen pen = new Pen(Color.Black,1);
e.Graphics.SetClip(vRegion,CombineMode.Exclude);
e.Graphics.DrawLine(pen,new Point(9,10),new Point(9,200));
e.Graphics.DrawLine(pen,new Point(11,10),new Point(11,200));
e.Graphics.Clip = oldRegion;
vRegion.Dispose();
pen.Dispose();
}
Because the clip region only have one pixel width, so the right vertical line may be shown.
But when I execute the code in .Net 2003, the right vertical line are clipped, only the left
vertical line exists.
If I set one pixel height clip rectangle and draw the two horizontal line just like previous
code, the bottom and top horizontal line will been shown. So I can't find the reason.