图片处理类(ImageClass)

using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using System;

namespace LiTianPing.Web.Controls
{
 /// <summary>
 /// 图片处理类
 /// 1、生成缩略图片或按照比例改变图片的大小和画质
 /// 2、将生成的缩略图放到指定的目录下
 /// </summary>
 public class ImageClass
 {
  public Image ResourceImage;
  private int ImageWidth;
  private int ImageHeight;
  public int imgWidth;

  public string ErrMessage;

  /// <summary>
  /// 类的构造函数
  /// </summary>
  /// <param name="ImageFileName">图片文件的全路径名称</param>
  public ImageClass(string ImageFileName)
  {
   ResourceImage=Image.FromFile(ImageFileName);
   imgWidth=ResourceImage.Width;
   ErrMessage="";
  }

  public bool ThumbnailCallback()
  {
   return false;
  }

  /// <summary>
  /// 生成缩略图重载方法1，返回缩略图的Image对象
  /// </summary>
  /// <param name="Width">缩略图的宽度</param>
  /// <param name="Height">缩略图的高度</param>
  /// <returns>缩略图的Image对象</returns>
  public Image GetReducedImage(int Width,int Height)
  {
   try
   {
    Image ReducedImage;

    Image.GetThumbnailImageAbort callb=new Image.GetThumbnailImageAbort(ThumbnailCallback);
    
    ReducedImage=ResourceImage.GetThumbnailImage(Width,Height,callb,IntPtr.Zero);
 
    return ReducedImage;
   }
   catch(Exception e)
   {
    ErrMessage=e.Message;
    return null;
   }
  }

  /// <summary>
  /// 生成缩略图重载方法2，将缩略图文件保存到指定的路径
  /// </summary>
  /// <param name="Width">缩略图的宽度</param>
  /// <param name="Height">缩略图的高度</param>
  /// <param name="targetFilePath">缩略图保存的全文件名，(带路径)，参数格式：D:Images ilename.jpg</param>
  /// <returns>成功返回true，否则返回false</returns>
  public bool GetReducedImage(int Width,int Height,string targetFilePath)
  {
   try
   {
    Image ReducedImage;

    Image.GetThumbnailImageAbort callb=new Image.GetThumbnailImageAbort(ThumbnailCallback);
    
    ReducedImage=ResourceImage.GetThumbnailImage(Width,Height,callb,IntPtr.Zero);
    ReducedImage.Save(@targetFilePath,ImageFormat.Jpeg);

    ReducedImage.Dispose();
 
    return true;
   }
   catch(Exception e)
   {
    ErrMessage=e.Message;
    return false;
   }
  }

  /// <summary>
  /// 生成缩略图重载方法3，返回缩略图的Image对象
  /// </summary>
  /// <param name="Percent">缩略图的宽度百分比 如：需要百分之80，就填0.8</param> 
  /// <returns>缩略图的Image对象</returns>
  public Image GetReducedImage(double Percent)
  {
   try
   {
    Image ReducedImage;

    Image.GetThumbnailImageAbort callb=new Image.GetThumbnailImageAbort(ThumbnailCallback);

    ImageWidth=Convert.ToInt32(ResourceImage.Width*Percent);
    ImageHeight=Convert.ToInt32(ResourceImage.Width*Percent);
    
    ReducedImage=ResourceImage.GetThumbnailImage(ImageWidth,ImageHeight,callb,IntPtr.Zero);
 
    return ReducedImage;
   }
   catch(Exception e)
   {
    ErrMessage=e.Message;
    return null;
   }
  }

  /// <summary>
  /// 生成缩略图重载方法4，返回缩略图的Image对象
  /// </summary>
  /// <param name="Percent">缩略图的宽度百分比 如：需要百分之80，就填0.8</param> 
  /// <param name="targetFilePath">缩略图保存的全文件名，(带路径)，参数格式：D:Images ilename.jpg</param>
  /// <returns>成功返回true,否则返回false</returns>
  public bool GetReducedImage(double Percent,string targetFilePath)
  {
   try
   {
    Image ReducedImage;

    Image.GetThumbnailImageAbort callb=new Image.GetThumbnailImageAbort(ThumbnailCallback);

    ImageWidth=Convert.ToInt32(ResourceImage.Width*Percent);
    ImageHeight=Convert.ToInt32(ResourceImage.Width*Percent);
    
    ReducedImage=ResourceImage.GetThumbnailImage(ImageWidth,ImageHeight,callb,IntPtr.Zero);

    ReducedImage.Save(@targetFilePath,ImageFormat.Jpeg);

    ReducedImage.Dispose();
 
    return true;
   }
   catch(Exception e)
   {
    ErrMessage=e.Message;
    return false;
   }
  }
  
  /// <summary>
  /// 生成缩略图重载方法5，返回缩略图的Image对象
  /// </summary>
  /// <param name="Width">缩略图的宽度</param>
  /// <param name="targetFilePath">>缩略图保存的全文件名，(带路径)，参数格式：D:Images ilename.jpg</param>
  /// <returns></returns>
  public bool GetReducedImage(int Width,string targetFilePath)
  {
   try
   {
    Image ReducedImage;

    Image.GetThumbnailImageAbort callb=new Image.GetThumbnailImageAbort(ThumbnailCallback);

    
    double Percent=Convert.ToDouble(Width)/Convert.ToDouble(ResourceImage.Width);
    Percent=Convert.ToDouble(Percent.ToString("#0.0"));
    //ImageWidth=Convert.ToInt32(ResourceImage.Width*Percent);
    ImageWidth=Width;
    ImageHeight=Convert.ToInt32(ResourceImage.Height*Percent);
    
    ReducedImage=ResourceImage.GetThumbnailImage(ImageWidth,ImageHeight,callb,IntPtr.Zero);

    ReducedImage.Save(@targetFilePath,ImageFormat.Jpeg);

    ReducedImage.Dispose();
 
    return true;
   }
   catch(Exception e)
   {
    ErrMessage=e.Message;
    return false;
   }
  }
 }
}