给图片加上水印

using System;
using System.Text;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;

namespace Baolee.GeneralMethod
{
 /// <summary>
 /// CropImage 的摘要说明。
 /// </summary>
 public class CropImage
 {
  /// <summary>
  /// 构造函数
  /// </summary>
  public CropImage()
  {
   //
   // TODO: 在此处添加构造函数逻辑
   //
  }
  /// <summary>
  /// 生成缩略图
  /// </summary>
  /// <param name="originalImagePath">源图路径（物理路径）</param>
  /// <param name="thumbnailPath">缩略图路径（物理路径）</param>
  /// <param name="width">缩略图宽度</param>
  /// <param name="height">缩略图高度</param>
  /// <param name="mode">生成缩略图的方式 HW|W|H|Cut </param>
  public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
  {
   Image image = Image.FromFile(originalImagePath);
   int num = width;
   int num2 = height;
   int x = 0;
   int y = 0;
   int num5 = image.Width;
   int num6 = image.Height;
   string str = mode;
   if (str != null)
   {
    str = string.IsInterned(str);
    if (str != "HW")
    {
     if (str == "W")
     {
      num2 = (image.Height * width) / image.Width;
     }
     else if (str == "H")
     {
      num = (image.Width * height) / image.Height;
     }
     else if (str == "Cut")
     {
      if ((((double) image.Width) / ((double) image.Height)) > (((double) num) / ((double) num2)))
      {
       num6 = image.Height;
       num5 = (image.Height * num) / num2;
       y = 0;
       x = (image.Width - num5) / 2;
      }
      else
      {
       num5 = image.Width;
       num6 = (image.Width * height) / num;
       x = 0;
       y = (image.Height - num6) / 2;
      }
     }
    }
   }
   Image image2 = new Bitmap(num, num2);
   Graphics graphics = Graphics.FromImage(image2);
   graphics.InterpolationMode = InterpolationMode.High;
   graphics.SmoothingMode = SmoothingMode.HighQuality;
   graphics.Clear(Color.Transparent);
   graphics.DrawImage(image, new Rectangle(0, 0, num, num2), new Rectangle(x, y, num5, num6), GraphicsUnit.Pixel);
   try
   {
    image2.Save(thumbnailPath, ImageFormat.Jpeg);
   }
   catch (Exception exception)
   {
    throw exception;
   }
   finally
   {
    image.Dispose();
    image2.Dispose();
    graphics.Dispose();
   }
  }
 

 }
}