c# bitmap的拷贝及一个图像工具类

                 using (Bitmap bmp = new Bitmap(scanImgPath))
                 {
                     Bitmap bitmap = new Bitmap(bmp.Width, bmp.Height, PixelFormat.Format16bppRgb555);
                     using (Graphics draw = Graphics.FromImage(bitmap))
                     {
                         draw.DrawImage(bmp, , , bitmap.Width, bitmap.Height);
                         picScanImg.Image = bitmap as Image;
                     }
                 }

 using System;
 using System.Collections.Generic;
 using System.Drawing;
 using System.Text;

 namespace TJCFinanceWriteOff.BizLogic.Common
 {
     public class ImageUtil
     {
         /// <summary>
         /// 图片镜像翻转
         /// </summary>
         /// <param name="imagePath">图片路径</param>
         /// <param name="isCover">是否覆盖</param>
         /// <returns></returns>
         public static Image ImageFlip(string imagePath,bool isCover = false)
         {
             Bitmap bitmap = Bitmap.FromFile(imagePath) as Bitmap;
             bitmap.RotateFlip(RotateFlipType.Rotate180FlipY);  //图片镜像翻转
             if (isCover is true) bitmap.Save(imagePath,System.Drawing.Imaging.ImageFormat.Jpeg);
             return bitmap;
         }

         /// <summary>
         /// 图片顺时针旋转180度
         /// </summary>
         /// <param name="imagePath">图片路径</param>
         /// <param name="isCover">是否覆盖</param>
         /// <returns></returns>
         public static Image ImageRotate(string imagePath,bool isCover = false)
         {
             Bitmap bitmap = Bitmap.FromFile(imagePath) as Bitmap;
             bitmap.RotateFlip(RotateFlipType.Rotate180FlipNone);  //图片顺时针180度
             if (isCover is true) bitmap.Save(imagePath,System.Drawing.Imaging.ImageFormat.Jpeg);
             return bitmap;
         }

         /// <summary>
         /// 图片等比缩放
         /// </summary>
         /// <param name="imagePath"></param>
         /// <returns></returns>
         public static Image ImageScaleZoom(string imagePath, double process)
         {
             Bitmap bitmap = Bitmap.FromFile(imagePath) as Bitmap;
             double width = bitmap.Width * process; ;//图片最终的宽
             double height = bitmap.Height * process;//图片最终的高
             return bitmap.GetThumbnailImage((int)width, (int)height, () => { return false; }, IntPtr.Zero);
         }

         public static Image ImageScaleZoom(Image sourceImage, double process)
         {
             double width = sourceImage.Width * process; ;//图片最终的宽
             double height = sourceImage.Height * process;//图片最终的高
             try
             {
                 System.Drawing.Imaging.ImageFormat format = sourceImage.RawFormat;
                 Bitmap targetPicture = new Bitmap((int)width, (int)height);
                 Graphics g = Graphics.FromImage(targetPicture);
                 g.DrawImage(sourceImage, , , (int)width, (int)height);
                 sourceImage.Dispose();
                 return targetPicture;
             }
             catch (Exception ex)
             {

             }
             return null;
         }

         public static Image ImageAssignZoom(Image sourceImage, int targetWidth, int targetHeight)
         {
             int width;//图片最终的宽
             int height;//图片最终的高
             try
             {
                 System.Drawing.Imaging.ImageFormat format = sourceImage.RawFormat;
                 Bitmap targetPicture = new Bitmap(targetWidth, targetHeight);
                 Graphics g = Graphics.FromImage(targetPicture);

                 if (sourceImage.Width > targetWidth && sourceImage.Height <= targetHeight)
                 {
                     width = targetWidth;
                     height = (width * sourceImage.Height) / sourceImage.Width;  //噶
                 }
                 else if (sourceImage.Width <= targetWidth && sourceImage.Height > targetHeight)
                 {
                     height = targetHeight;
                     width = (height * sourceImage.Width) / sourceImage.Height;
                 }
                 else if (sourceImage.Width <= targetWidth && sourceImage.Height <= targetHeight)
                 {
                     width = sourceImage.Width;
                     height = sourceImage.Height;
                 }
                 else
                 {
                     width = targetWidth;
                     height = (width * sourceImage.Height) / sourceImage.Width;
                     if (height > targetHeight)
                     {
                         height = targetHeight;
                         width = (height * sourceImage.Width) / sourceImage.Height;
                     }
                 }
                 g.DrawImage(sourceImage, , , width, height);
                 sourceImage.Dispose();

                 return targetPicture;
             }
             catch (Exception ex)
             {

             }
             return null;
         }
     }
 }