.net生成缩略图类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;

namespace common
{
  public  class Thumbnail
  {
    private string _orgPath;
        private string _newPath;
        private double _width;
        private double _height;
        private double _orgWidth;
        private double _orgHeight;
        private Image image;
        /// <summary>
        /// 构造函数
        /// </summary>
        public  Thumbnail()
        {
        }
        /// <summary>
        /// 构造构数
        /// </summary>
        /// <param name="orgpath"></param>
        public Thumbnail(string orgpath)
        {
            this.OrgPath = orgpath;
            setWH();
        }
        /// <summary>
        /// 构造构数
        /// </summary>
        /// <param name="image"></param>
        public Thumbnail(Image image)
        {
            this.image = image;
            this.OrgHeight= image.Height;
            this.OrgWidth = image.Width;
        }
        /// <summary>
        ///
        /// </summary>
        /// <param name="orgpath">原路径</param>
        /// <param name="newpath">新路径</param>
        /// <param name="width">新宽度</param>
        /// <param name="height">新高度</param>
        /// <param name="orgwidth">原宽度</param>
        /// <param name="orgheight">原高度</param>
        public Thumbnail(string orgpath, string newpath, int width, int height, int orgwidth, int orgheight)
        {
            this.NewPath= newpath;
            this.OrgPath = orgpath;
            this.Width = width;
            this.Height= height;
            this.OrgWidth= orgwidth;
            this.OrgHeight = orgheight;
        }
        /// <summary>
        /// 原路径
        /// </summary>
        public string OrgPath
        {
            get
            {
                return _orgPath;
            }
            set
            {
                _orgPath = value;
            }
        }
        /// <summary>
        /// 新路径
        /// </summary>
        public string NewPath
        {
            get
            {
                return _newPath;
            }
            set
            {
                _newPath = value;
            }
        }
        /// <summary>
        /// 新高度
        /// </summary>
        public int Width
        {
            set
            {
                _width = value;
            }
        }
        /// <summary>
        /// 新宽度
        /// </summary>
        public int Height
        {
            set { _height = value; }
        }
        /// <summary>
        /// 原宽度
        /// </summary>
        public int OrgWidth
        {
            set
            {
                _orgWidth = value;
            }
        }
        /// <summary>
        /// 原高度
        /// </summary>
        public int OrgHeight
        {
            set
            {
                _orgHeight = value;
            }
        }
        /// <summary>
        /// 产生缩略图
        /// </summary>
        public void Make()
        {
            if (!string.IsNullOrEmpty(_orgPath))
            {
                image = Image.FromFile(_orgPath);
            }
            double w = _width;
            double h = _height;
         
            if (image.Width > w)
            {
                CreateThumbnail(_newPath, w, h);
            }
            else
            {
                image.Save(_newPath);

            }

        }
        /// <summary>
        /// 建立缩略图
        /// </summary>
        /// <param name="sFileDstPath">目标路径</param>
        /// <param name="LimitW">限制宽</param>
        /// <param name="LimitH">限制高</param>
        private void CreateThumbnail(string sFileDstPath, double LimitW, double LimitH)
        {
            if (this.image != null)
            {
                System.Drawing.Image image = this.image as System.Drawing.Bitmap;
                byte[] data;
                ImageCodecInfo myImageCodecInfo;
                System.Drawing.Imaging.Encoder myEncoder;
                EncoderParameter myEncoderParameter;
                EncoderParameters myEncoderParameters;
                myImageCodecInfo = ImageCodecInfo.GetImageEncoders()[0];
                myEncoder = System.Drawing.Imaging.Encoder.Quality;
                myEncoderParameters = new EncoderParameters(1);
                myEncoderParameter = new EncoderParameter(myEncoder, 100L);
                myEncoderParameters.Param[0] = myEncoderParameter;
                MemoryStream ms = new MemoryStream();
                image.Save(ms, myImageCodecInfo, myEncoderParameters);
                CreateThumbnail(ms.ToArray(), out data, LimitW, LimitH);
                image = System.Drawing.Image.FromStream(new MemoryStream(data)) as System.Drawing.Bitmap;
                image.Save(sFileDstPath);
            }
        }
        /// <summary>
        /// 生成缩略图纯数据
        /// </summary>
        /// <param name="data1">数据1</param>
        /// <param name="data2">数据2</param>
        /// <param name="LimitW">限宽</param>
        /// <param name="LimitH">限高</param>
        static public void CreateThumbnail(byte[] data1, out byte[] data2, double LimitW, double LimitH)
        {
            System.Drawing.Image image = System.Drawing.Image.FromStream(new MemoryStream(data1)) as System.Drawing.Bitmap;
            System.Drawing.SizeF size = new System.Drawing.SizeF(image.Width, image.Height);
            size.Width = (float)LimitW;
            size.Height = (float)LimitH;
            if (size.Height <= 0)
            {
                size.Height = image.Height * size.Width / image.Width;
            }
            if (size.Width <= 0)
            {
                size.Width = image.Width * size.Height / image.Height;
            }
            System.Drawing.Image bitmap = new System.Drawing.Bitmap(Convert.ToInt16(size.Width), Convert.ToInt16(size.Height));
            System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            g.Clear(Color.Transparent);
            Rectangle rect = new Rectangle(0, 0, bitmap.Width, bitmap.Height);
            g.DrawImage(image, rect, new System.Drawing.Rectangle(0, 0, image.Width, image.Height), System.Drawing.GraphicsUnit.Pixel);
            ImageCodecInfo myImageCodecInfo;
            System.Drawing.Imaging.Encoder myEncoder;
            EncoderParameter myEncoderParameter;
            EncoderParameters myEncoderParameters;
            myImageCodecInfo = ImageCodecInfo.GetImageEncoders()[0];
            myEncoder = System.Drawing.Imaging.Encoder.Quality;
            myEncoderParameters = new EncoderParameters(1);
            myEncoderParameter = new EncoderParameter(myEncoder, 100L);
            myEncoderParameters.Param[0] = myEncoderParameter;
            MemoryStream ms = new MemoryStream();
            bitmap.Save(ms, myImageCodecInfo, myEncoderParameters);
            data2 = ms.ToArray();
            myEncoderParameter.Dispose();
            myEncoderParameters.Dispose();
            image.Dispose();
            bitmap.Dispose();
            g.Dispose();
            ms.Dispose();
        }
        /// <summary>
        /// 根据图片路径获取图片大小并设置
        /// </summary>
        private void setWH()
        {
            Bitmap bitmap = new Bitmap(_orgPath);
            this.OrgWidth = bitmap.Width;
            this.OrgHeight = bitmap.Height;
        }
    }
}