Drawing on picture box images





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Drawing on picture box images
You can draw an Ellipse on the pictureBox image using the following code:
public void drawEllipse(PictureBox pb, int x, int y, int w, int h, float Bwidth,Color col)
{
//refresh the picture box
pb.Refresh();
//create a graphics object
Graphics g = pb.CreateGraphics();
//create a pen object
Pen p = new Pen(col, Bwidth);
//draw Ellipse
g.DrawEllipse(p, x, y, w, h);
//dispose pen and graphics object
p.Dispose();
g.Dispose();
}
In here, I grab the picturebox
graphics using pb.CreateGraphics()
so that I can draw on its surface. But drawing on the PictureBox
only affects the pixels on the screen, not the pixels in the image. You can however, obtain the Graphics for the image. You can see that in the next example.
You can draw a line on the pictureBox
image using the following code:
public void drawline(PictureBox pb, Point p1, Point p2, float Bwidth,Color c1)
{
//refresh the picture box
pb.Refresh();
//create a new Bitmap object
Bitmap map=(Bitmap)pb.Image;
//create a graphics object
Graphics g = Graphics.FromImage(map);
//create a pen object and setting the color and width for the pen
Pen p = new Pen(c1, Bwidth);
//draw line between point p1 and p2
g.DrawLine(p, p1, p2);
pb.Image = map;
//dispose pen and graphics object
p.Dispose();
g.Dispose();
}
After creating the graphics object(g
), there are several predefined methods you can use to draw objects. Some are listed below:
g.DrawArc g.DrawCurve g.DrawBezier g.DrawIcon g.DrawImage g.DrawPath g.DrawRectangle