using system;

using system.data;

using system.configuration;

using system.web;

using system.web.security;

using system.web.ui;

using system.web.ui.webcontrols;

using system.web.ui.webcontrols.webparts;

using system.web.ui.htmlcontrols;

using system.io;

using system.drawing;

using system.drawing.imaging;

///

/// 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

///

public class imageclass

{

public system.drawing.image resourceimage;

private int imagewidth;

private int imageheight;

public string errmessage;

///

/// 类的构造函数

///

/// 图片文件的全路径名称

public imageclass(string imagefilename)

{

resourceimage = system.drawing.image.fromfile(imagefilename);

errmessage = ;

}

public bool thumbnailcallback()

{

return false;

}

///

/// 生成缩略图重载方法1，返回缩略图的image对象

///

/// 缩略图的宽度

/// 缩略图的高度

/// 缩略图的image对象

public system.drawing.image getreducedimage(int width, int height)

{

try

{

system.drawing.image reducedimage;

system.drawing.image.getthumbnailimageabort callb = new system.drawing.image.getthumbnailimageabort(thumbnailcallback);

reducedimage = resourceimage.getthumbnailimage(width, height, callb, intptr.zero);

return reducedimage;

}

catch (exception e)

{

errmessage = e.message;

return null;

}

}

///

/// 生成缩略图重载方法2，将缩略图文件保存到指定的路径

///

/// 缩略图的宽度

/// 缩略图的高度

/// 缩略图保存的全文件名，(带路径)，参数格式：d:images ilename.jpg

/// 成功返回true，否则返回false

public bool getreducedimage(int width, int height, string targetfilepath)

{

try

{

system.drawing.image reducedimage;

system.drawing.image.getthumbnailimageabort callb = new system.drawing.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;

}

}

///

/// 生成缩略图重载方法3，返回缩略图的image对象

///

/// 缩略图的宽度百分比 如：需要百分之80，就填0.8

/// 缩略图的image对象

public system.drawing.image getreducedimage(double percent)

{

try

{

system.drawing.image reducedimage;

system.drawing.image.getthumbnailimageabort callb = new system.drawing.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;

}

}

///

/// 生成缩略图重载方法4，返回缩略图的image对象

///

/// 缩略图的宽度百分比 如：需要百分之80，就填0.8

/// 缩略图保存的全文件名，(带路径)，参数格式：d:images ilename.jpg

/// 成功返回true,否则返回false

public bool getreducedimage(double percent, string targetfilepath)

{

try

{

system.drawing.image reducedimage;

system.drawing.image.getthumbnailimageabort callb = new system.drawing.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;

}

}

}

更多信息请查看IT技术专栏