求asp．net 图片上传压缩图片大小代码 就是减小图片的分辨率存储图片到服务器

c#生成缩略图的类

using SystemIO;

using SystemDrawing;

using SystemDrawingImaging;

/// <summary>

/// 处理类

/// 1、生成缩略或按照比例改变的大小和画质

/// 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">文件的全路径名称</param>

public ImageClass(string ImageFileName)

{

ResourceImage=ImageFromFile(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;

ImageGetThumbnailImageAbort callb=new ImageGetThumbnailImageAbort(ThumbnailCallback);

ReducedImage=ResourceImageGetThumbnailImage(Width,Height,callb,IntPtrZero);

return ReducedImage;

}

catch(Exception e)

{

ErrMessage=eMessage;

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 ilenamejpg</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;

ImageGetThumbnailImageAbort callb=new ImageGetThumbnailImageAbort(ThumbnailCallback);

ReducedImage=ResourceImageGetThumbnailImage(Width,Height,callb,IntPtrZero);

ReducedImageSave(@targetFilePath,ImageFormatJpeg);

ReducedImageDispose();

return true;

}

catch(Exception e)

{

ErrMessage=eMessage;

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08</param>

/// <returns>缩略图的Image对象</returns>

public Image GetReducedImage(double Percent)

{

try

{

Image ReducedImage;

ImageGetThumbnailImageAbort callb=new ImageGetThumbnailImageAbort(ThumbnailCallback);

ImageWidth=ConvertToInt32(ResourceImageWidthPercent);

ImageHeight=ConvertToInt32(ResourceImageWidthPercent);

ReducedImage=ResourceImageGetThumbnailImage(ImageWidth,ImageHeight,callb,IntPtrZero);

return ReducedImage;

}

catch(Exception e)

{

ErrMessage=eMessage;

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08</param>

/// <param name="targetFilePath">缩略图保存的全文件名，(带路径)，参数格式：D:Images ilenamejpg</param>

/// <returns>成功返回true,否则返回false</returns>

public bool GetReducedImage(double Percent,string targetFilePath)

{

try

{

Image ReducedImage;

ImageGetThumbnailImageAbort callb=new ImageGetThumbnailImageAbort(ThumbnailCallback);

ImageWidth=ConvertToInt32(ResourceImageWidthPercent);

ImageHeight=ConvertToInt32(ResourceImageWidthPercent);

ReducedImage=ResourceImageGetThumbnailImage(ImageWidth,ImageHeight,callb,IntPtrZero);

ReducedImageSave(@targetFilePath,ImageFormatJpeg);

ReducedImageDispose();

return true;

}

catch(Exception e)

{

ErrMessage=eMessage;

return false;

}

}

}

本篇文章来源于：开发学院 http://educodepubcom 原文链接：http://educodepubcom/2011/0118/28884php

数据库存储，其实是存储在服务器上的路径或的绝对地址 。它是一个字符串，所以数据库字段的类型可使用varchar可变的，长度不超过255。在前台调用时，需要将路径放置在img标签的src属性中，即可显示