如何将图形转换为图像或位图？

Question

How to convert Graphics into Image or Bitmap?

I have this code and it successfully crops my image in a picturebox but when I try to save it into a database.. it's empty.

Bitmap sourceBitmap = new Bitmap(pctImage.Image, pctImage.Width, pctImage.Height);
Graphics g = frmAdd.pctImage.CreateGraphics();

Rectangle rectCropArea;
rectCropArea = new Rectangle(50, 3, 230, 240);

g.DrawImage(sourceBitmap, new Rectangle(0, 0, frmAdd.pctImage.Width, frmAdd.pctImage.Height), rectCropArea, GraphicsUnit.Pixel);
sourceBitmap.Dispose();

What should I do with this one? Thanks.

Answer 1

像这样：

  Bitmap bmp = new Bitmap(100,100,graphics);

Answer 2

Use a structure like this:

using (Bitmap bitmap = new Bitmap(rectangle.Width, rectangle.Height))
        {
            using (Graphics graphics = Graphics.FromImage(bitmap))
            {
               //draw image..
            }
            return bitmap;
        }