asp.net 生成缩略图代码


            复制代码 代码如下: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; /// <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 System.Drawing.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 = System.Drawing.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 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; } } /// <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 { 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; } } /// <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 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; } } /// <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 { 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; } } }