代码如下：

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Drawing.Drawing2D;
using System.Drawing;
using System.Drawing.Imaging;
namespace MyWaterMark
{
    ///  
    /// WaterMark 的摘要说明 
    ///  
    /// edit by www.
    /// 要加入的文字  
    /// 要加入的文字颜色  
    /// 水印图片路径  
    /// 要加水印的图片路径  
    /// 处理后的图片路径  
    /// 水印在修改图片中距左边的宽度  
    /// 水印在修改图片中距底部的高度  
    /// 水印图片的透明度  
    /// 文字  
    /// 文字  
    /// 文字  
    /// 是否显示文字  
    /// 是否显示水印图片 
    public class WaterMark
    {
        #region param
        private string strCopyright, strMarkPath, strPhotoPath, strSavePath;
        private int iMarkRightSpace, iMarkButtomSpace, iDiaphaneity;
        private int iFontRightSpace = 0, iFontButtomSpace = 0, iFontDiaphaneity = 80;
        private int iFontSize = 10;
        private bool bShowCopyright = true, bShowMarkImage = true;
        private int red = 0, greed = 0, blue = 0;
        Image imageBit=null;

        #endregion
        #region WaterMark
        public WaterMark()
        {
            this.strCopyright = "";
            this.strMarkPath = null;
            this.strPhotoPath = null;
            this.strSavePath = null;
            this.iDiaphaneity = 70;
            this.iMarkRightSpace = 0;
            this.iMarkButtomSpace = 0;
        }
        ///  
        /// 主要用两样都加的 
        ///  
        public WaterMark(string copyright, string copyrightColor, string markPath, string photoPath,Image imageBitT, string savePath,int apha)
        {
            this.strCopyright = copyright;
            this.strMarkPath = markPath;
            this.strPhotoPath = photoPath;
            this.strSavePath = savePath;
            this.iDiaphaneity = apha;
            this.iMarkRightSpace = 0;
            this.iMarkButtomSpace = 0;
            this.imageBit = imageBitT;
            try
            {
                Color my = new Color();
                if (copyrightColor.IndexOf("#") >= 0)
                {
                    my = ColorTranslator.FromHtml(copyrightColor);
                }
                else
                {
                    my = Color.FromName(copyrightColor);
                }
                this.red = my.R;
                this.greed = my.G;
                this.blue = my.B;
            }
            catch (Exception) { }
        }
        #endregion
        #region property
        ///  
        /// 设置是否显示水印文字 
        ///  
        public bool ShowCopyright
        {
            set { this.bShowCopyright = value; }
        }
        ///  
        /// 设置是否显示水印图片 
        ///  
        public bool ShowMarkImage
        {
            set { this.bShowMarkImage = value; }
        }
        ///  
        /// 获取或设置要加入的文字 
        ///  
        public string Copyright
        {
            set { this.strCopyright = value; }
        }
        ///  
        /// 设置要加入的文字颜色
        ///  
        public bool strCopyrightColor
        {
            set
            {
                Color my = new Color();
                if (value.ToString().IndexOf("#") >= 0)
                {
                    my = ColorTranslator.FromHtml(value.ToString());
                }
                else
                {
                    my = Color.FromName(value.ToString());
                }
                this.red = my.R;
                this.greed = my.G;
                this.blue = my.B;
            }
        }
        ///  
        /// 获取或设置加水印后的图片路径 
        ///  
        public string SavePath
        {
            get { return this.strSavePath; }
            set { this.strSavePath = value; }
        }
        ///  
        /// 获取或设置水印图片路径 
        ///  
        public string MarkPath
        {
            get { return this.strMarkPath; }
            set { this.strMarkPath = value; }
        }
        ///  
        /// 获取或设置要加水印图片的路径 
        ///  
        public string PhotoPath
        {
            get { return this.strPhotoPath; }
            set { this.strPhotoPath = value; }
        }
        ///  
        /// 设置水印图片的透明度 
        ///  
        public int Diaphaneity
        {
            set
            {
                if (value > 0 && value = 0 && value