C# 保存窗口为图片（保存纵断面图）

源代码例如以下：

     #region 保存纵断面截图

        private void button_save_Click(object sender , EventArgs e)
        {
            SaveFileDialog saveImageDialog = new SaveFileDialog();
            saveImageDialog.Title = "保存纵断面图";
            saveImageDialog.DefaultExt = ".png";
            saveImageDialog.FileName = Linefeaturelayer.Name + "纵断面图";
            saveImageDialog.InitialDirectory = "C:\";

            DialogResult dr = saveImageDialog.ShowDialog();
            if (dr==DialogResult.OK)
            {
                CaptureImage(saveImageDialog.FileName);
                MessageBox.Show("保存成功。");
            }

        }

        private void CaptureImage(string path)
        {
            try
            {
                //获得当前屏幕的大小
                Rectangle rect = new Rectangle();
                rect = Screen.GetWorkingArea(this);
                //创建一个以当前屏幕为模板的图象
                Graphics g1 = this.CreateGraphics();
                //创建以屏幕大小为标准的位图 
                Image MyImage = new Bitmap(rect.Width , rect.Height , g1);
                Graphics g2 = Graphics.FromImage(MyImage);
                //得到屏幕的DC
                IntPtr dc1 = g1.GetHdc();
                //得到Bitmap的DC 
                IntPtr dc2 = g2.GetHdc();
                //调用此API函数。实现屏幕捕获
                BitBlt(dc2 , 0 , 0 , rect.Width , rect.Height , dc1 , 0 , 0 , 13369376);
                //释放掉屏幕的DC
                g1.ReleaseHdc(dc1);
                //释放掉Bitmap的DC 
                g2.ReleaseHdc(dc2);
                //以JPG文件格式来保存
                MyImage.Save(path , ImageFormat.Png);
            }
            catch (System.Exception ex)
            {
                MessageBox.Show(ex.Message + " 保存图片失败。"); 
            }
        }

        //声明一个API函数
        [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]
     
        private static extern bool BitBlt(
            
            IntPtr hdcDest , // 目标 DC的句柄
            int nXDest ,
            int nYDest ,
            int nWidth ,
            int nHeight ,
            IntPtr hdcSrc ,  // 源DC的句柄
            int nXSrc ,
            int nYSrc ,
            System.Int32 dwRop  // 光栅的处理数值
            
            );

        #endregion

效果图：