A first chance exception of type 'System.ArgumentException' occurred in System.Drawing.dll

Question

I'm trying to make a fullscreen screencapture and load it into an pictureBox, but it's giving me this error: A first chance exception of type 'System.ArgumentException' occurred in System.Drawing.dll Additional information: Ongeldige parameter.

Code:

    using (Bitmap bmpScreenCapture = new Bitmap(Screen.PrimaryScreen.Bounds.Width,
                                                Screen.PrimaryScreen.Bounds.Height))
    {
        using (Graphics g = Graphics.FromImage(bmpScreenCapture))
        {
            g.CopyFromScreen(Screen.PrimaryScreen.Bounds.X,
                             Screen.PrimaryScreen.Bounds.Y,
                             0, 0,
                             bmpScreenCapture.Size,
                             CopyPixelOperation.SourceCopy);
        }

        pictureBox1.Image = bmpScreenCapture;
    }

Joery.

Answer 1

The exception occurs because the using statement disposes of the Bitmap after it's assigned to pictureBox1.Image, so the PictureBox is unable to display the bitmap when it's time to repaint itself:

using (Bitmap bmpScreenCapture = new Bitmap(Screen.PrimaryScreen.Bounds.Width,
                                            Screen.PrimaryScreen.Bounds.Height))
{
    // ...

    pictureBox1.Image = bmpScreenCapture;
} // <== bmpScreenCapture.Dispose() gets called here.

// Now pictureBox1.Image references an invalid Bitmap.

To fix the problem, keep the Bitmap variable declaration and initializer, but remove the using:

Bitmap bmpScreenCapture = new Bitmap(Screen.PrimaryScreen.Bounds.Width,
                                     Screen.PrimaryScreen.Bounds.Height);

// ...

pictureBox1.Image = bmpScreenCapture;

You should still make sure the Bitmap gets disposed eventually, but only when you truly don't need it anymore (for example, if you replace pictureBox1.Image by another bitmap later).