How to zoom in on a image with Zoom button?

[mrcw]

Hi, Im trying to zoom in on an image. First I make a .bmp from the picturebox.imag e the make the.bmp bigger the put the new .bmp back into the picturebox. All this does is make my image disappear.Why?

  private void btnZoomIn_Click(object sender, EventArgs e)
        {
            Bitmap a = new Bitmap(pictureBox1.Image.Height * 2, pictureBox1.Image.Width * 2);  
            pictureBox1.Image = a; 
           
        }

[hype261]

The reason that your Bitmap disappears is because you just constructed a blank Bitmap with a specific size. None of the data in the original bitmap is being used. The constructor you want to use is.

Size newSize = new Size(pictureBox1.Image,Width *2,pictureBox1.Image.Height *2 );
Bitmap a = new Bitmap(pictureBox1.Image,newSize);

This will scale your original bitmap up to that size

[mrcw]

thanks for that. Why doesn't it work when scalar = 50 instead of 2?