PictureBox not redrawing after RotateFlipType but it works with a breakpoint

Question

I have simplified this to make sure nothing else is going on. So I have a windows form application, 1 form, 1 button and 1 picturebox. The following is the only code I have added.

    private void button1_Click(object sender, EventArgs e)
    {
        pictureBox1.Image.RotateFlip(RotateFlipType.Rotate90FlipNone);
        Application.DoEvents();
    }

When I have a breakpoint in this routine the picture is shown as rotated. If Idon't have a breakpoint the picture does not rotate.

Any ideas? The code can't get more simple.

Answer 1

You need to call either Refresh() or Invalidate() function on PictureBox control to Update it after Rotating.

From MSDN:Invalidate

Invalidates the entire surface of the control and causes the control to be redrawn.

Try : using Invalidate()

 private void button1_Click(object sender, EventArgs e)
        {
            pictureBox1.Image.RotateFlip(RotateFlipType.Rotate90FlipNone);
            pictureBox1.Invalidate();
            Application.DoEvents();
        }

Answer 2

Try this :

 pictureBox1.Image.RotateFlip(RotateFlipType.Rotate90FlipNone);
 pictureBox1.Refresh();
 Application.DoEvents();