关于生成缩略图:c#

里面有4个重载方法,有直接返回Image对象的,有生成缩略图,并且保存到指定目录的!
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;

/// <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 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);
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/filename.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/filename.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;
}
}

}