Never use control.CreateGraphics
! Either draw into a Bitmap bmp
using a Graphics g = Graphics.FromImage(bmp)
or in the Paint
event of a control, using the e.Graphics
parameter..
Here is a cropping code that draws into a new Bitmap and that makes use of your controls etc but changes a few things:
- It uses a
Graphics
object that is created from a new Bitmap
- It make use of
using
clauses to make sure it won't leak
- It takes the size of the
pictureBox3.ClientSize
so it won't include any borders..
private void crop_bttn_Click(object sender, EventArgs e)
{
Image crop = GetCopyImage("grayScale.jpg");
pictureBox2.Image = crop;
Bitmap targetBitmap = new Bitmap(pictureBox3.ClientSize.Width,
pictureBox3.ClientSize.Height);
using (Bitmap sourceBitmap = new Bitmap(pictureBox2.Image,
pictureBox2.ClientSize.Width, pictureBox2.ClientSize.Height))
{
using (Graphics g = Graphics.FromImage(targetBitmap))
{
g.DrawImage(sourceBitmap, new Rectangle(0, 0,
pictureBox3.ClientSize.Width, pictureBox3.ClientSize.Height),
rectCropArea, GraphicsUnit.Pixel);
}
}
if (pictureBox3.Image != null) pictureBox3.Image.Dispose();
pictureBox3.Image = targetBitmap;
targetBitmap.Save(somename, someFormat);
}
The alternative would be to..:
- move all your code to the
Paint
event
- replace the
Graphics g = pictureBox3.CreateGraphics();
be Graphics g = e.Graphics;
- insert these two lines to the click event:
Bitmap targetBitmap = new Bitmap(pictureBox3.ClientSize.Width,
pictureBox3.ClientSize.Height);
pictureBox3.DrawToBitmap(targetBitmap, pictureBox3.ClientRectangle);
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