//截取全屏图象        private void btnFullScreen_Click(object sender, EventArgs e)        {            //创建图象，保存将来截取的图象            Bitmap image = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);            Graphics imgGraphics = Graphics.FromImage(image);            //设置截屏区域            imgGraphics.CopyFromScreen(0, 0, 0, 0, new Size(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height));            //保存            SaveImage(image);        }//保存图象文件        private void SaveImage(Image image)        {            if (saveFileDialog.ShowDialog(this) == DialogResult.OK)            {                string fileName = saveFileDialog.FileName;                string extension = Path.GetExtension(fileName);                if (extension == ".jpg")                {                    image.Save(fileName, ImageFormat.Jpeg);                }                else                {                    image.Save(fileName, ImageFormat.Bmp);                }            }        }