批量生成缩略图

.net实现批量生成多种格式缩略图，自动根据宽高做判断，固定宽或高，高或宽按比例生成

1.实现代码：

　1.1.调用方法：

http://localhost/Default.aspx?year=2010&month=8&day=8

1.2.web.config配置

1.3.default.aspx.cs

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using System; 

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using System.Collections; 

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using System.Configuration; 

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using System.Data; 

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using System.Web; 

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using System.Web.Security; 

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using System.Web.UI; 

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using System.Web.UI.HtmlControls; 

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using System.Web.UI.WebControls; 

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using System.Web.UI.WebControls.WebParts; 

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using System.IO; 

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using System.Net; 

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using System.Text.RegularExpressions; 

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public partial class _Default : System.Web.UI.Page 

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{ 

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    protected void Page_Load(object sender, EventArgs e) 

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    { 

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        if (!Page.IsPostBack) 

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        { 

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            //调用方法：http://localhost/Default.aspx?year=2010&month=8&day=8 

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            string year = HttpContext.Current.Request.QueryString["year"]; 

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            string month = HttpContext.Current.Request.QueryString["month"]; 

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            string day = HttpContext.Current.Request.QueryString["day"]; 

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            OpratePic(year, month, day); 

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        } 

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    } 

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    protected void OpratePic(string year, string month, string day) 

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    { 

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        string treePath = HttpContext.Current.Server.MapPath("") + "\\pic\\"; 

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        string otherPath = HttpContext.Current.Server.MapPath("")+ "\\slt\\"; 

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        if (!string.IsNullOrEmpty(year) && !string.IsNullOrEmpty(month) && !string.IsNullOrEmpty(day)) 

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        { 

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            string treePath1 = treePath + year.ToString() + "\\" + month.ToString() + "\\" + day.ToString() + "\\"; 

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            string otherPath1 = otherPath + year.ToString() + "\\" + month.ToString() + "\\" + day.ToString() + "\\"; 

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            GeneratePic(treePath1, otherPath1); 

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            Response.Write("生成成功<br/>"); 

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        } 

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        else if (!string.IsNullOrEmpty(year) && !string.IsNullOrEmpty(month)) 

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        { 

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            treePath = treePath + year.ToString() + "\\" + month.ToString() + "\\"; 

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            otherPath = otherPath + year.ToString() + "\\" + month.ToString() + "\\"; 

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            for (int c = 1; c < 32; c++) 

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            { 

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                string treePath1 = treePath + c.ToString() + "\\"; 

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                string otherPath1 = otherPath + c.ToString() + "\\"; 

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                GeneratePic(treePath1, otherPath1); 

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            } 

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            Response.Write("生成成功<br/>"); 

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        } 

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        else if (!string.IsNullOrEmpty(year)) 

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        { 

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            treePath = treePath + year.ToString() + "\\"; 

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            otherPath = otherPath + year.ToString() + "\\"; 

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            for (int b = 1; b < 13; b++) 

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            { 

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                for (int c = 1; c < 32; c++) 

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                { 

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                    string treePath1 = treePath +  "\\" + b.ToString() + "\\" + c.ToString() + "\\"; 

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                    string otherPath1 = otherPath  + "\\" + b.ToString() + "\\" + c.ToString() + "\\"; 

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                    GeneratePic(treePath1, otherPath1); 

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                } 

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            } 

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            Response.Write("生成成功<br/>"); 

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        } 

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        else

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        { 

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            Response.Write("输入参数有误！<br/>"); 

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            Response.Write("缩略图格式如下：<br/>"); 

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            Response.Write("http://photo.jmw.com.cn/default.aspx?year=2008&month=12&day=20<br/>"); 

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        } 

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    } 

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    protected void GeneratePic(string treePath, string otherPath) 

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    { 

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        if (Directory.Exists(treePath)) 

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        { 

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            string[] stringFiles = Directory.GetFiles(treePath); 

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            foreach (string stringFile in stringFiles) 

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            { 

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                FileInfo file = new FileInfo(stringFile); 

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                if (file.Length > 0) 

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                { 

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                    //(||)jpgbmpgif 

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                    if (Regex.IsMatch(file.Name, @".*\.(?:jpg|gif|jpeg|bmp|png)$", RegexOptions.IgnoreCase)) 

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                    { 

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                        string webFilePath = treePath + file.Name;          // 服务器端文件路径 

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                        string webFilePath_s1 = otherPath + "S1_" + file.Name;　　  // 服务器端缩略图路径 

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                        string webFilePath_s2 = otherPath + "S2_" + file.Name; 

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                        string webFilePath_s3 = otherPath + "S3_" + file.Name; 

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                        string webFilePath_s11 = otherPath + "S1_1_" + file.Name; 

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                        string webFilePath_s22 = otherPath + "S2_2_" + file.Name; 

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                        string webFilePath_s33 = otherPath + "S3_3_" + file.Name; 

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                        if (!Directory.Exists(otherPath)) //如果目录不存在则创建 

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                        { 

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                            Directory.CreateDirectory(otherPath); 

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                        } 

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                        MakeThumbnail(webFilePath, webFilePath_s22, 250, 188, "W");     // 生成缩略图方法W:指定宽，高按比例 

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                        MakeThumbnail(webFilePath_s22, webFilePath_s2, 250, 188, "Cut"); 

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                        MakeThumbnail(webFilePath, webFilePath_s11, 152, 114, "W");     // 生成缩略图方法W:指定宽，高按比例 

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                        MakeThumbnail(webFilePath_s11, webFilePath_s1, 152, 114, "Cut"); 

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                        MakeThumbnail(webFilePath, webFilePath_s33, 38, 29, "W");     // 生成缩略图方法W:指定宽，高按比例 

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                        MakeThumbnail(webFilePath_s33, webFilePath_s3, 38, 29, "Cut"); 

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                    } 

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                } 

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            } 

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        } 

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    } 

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    #region 生成缩略图 

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    /// 〈summary> 

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    /// 生成缩略图 

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    /// 〈/summary> 

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    /// 〈param name="originalImagePath">源图路径（物理路径）〈/param> 

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    /// 〈param name="thumbnailPath">缩略图路径（物理路径）〈/param> 

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    /// 〈param name="width">缩略图宽度〈/param> 

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    /// 〈param name="height">缩略图高度〈/param> 

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    /// 〈param name="mode">生成缩略图的方式〈/param>     

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    public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode) 

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    { 

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        try

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        { 

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            using (System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath)) 

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            { 

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                if (mode != "Cut") 

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                { 

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                    double d1 = double.Parse(width.ToString()) / double.Parse(height.ToString()); 

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                    //宽高比 

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                    double wd = double.Parse(originalImage.Width.ToString()) / double.Parse(originalImage.Height.ToString()); 

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                    //高宽比 

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                    double hd = double.Parse(originalImage.Height.ToString()) / double.Parse(originalImage.Width.ToString()); 

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                    double itsw = 0d; 

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                    double itsh = 0d; 

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                    int itsin = 0; 

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                    //与宽高比对比 

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                    if (d1 > wd) 

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                    { 

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                        itsw = d1 - wd; 

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                    } 

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                    else

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                    { 

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                        itsw = wd - d1; 

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                    } 

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                    //与高宽比对比 

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                    if (d1 > hd) 

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                    { 

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                        itsh = d1 - hd; 

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                    } 

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                    else

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                    { 

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                        itsh = hd - d1; 

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                    } 

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                    //如果高宽比更接近比例 

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                    if (itsw > itsh) 

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                    { 

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                        mode = "W"; 

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                    } 

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                    else

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                    { 

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                        mode = "H"; 

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                    } 

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                } 

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                int towidth = width; 

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                int toheight = height; 

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                int x = 0; 

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                int y = 0; 

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                int ow = originalImage.Width; 

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                int oh = originalImage.Height; 

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                switch (mode) 

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                { 

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                    case "HW"://指定高宽缩放（可能变形）                 

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                        break; 

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                    case "W"://指定宽，高按比例                     

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                        toheight = originalImage.Height * width / originalImage.Width; 

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                        break; 

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                    case "H"://指定高，宽按比例 

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                        towidth = originalImage.Width * height / originalImage.Height; 

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                        break; 

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                    case "Cut"://指定高宽裁减（不变形）                 

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                        if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight) 

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                        { 

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                            oh = originalImage.Height; 

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                            ow = originalImage.Height * towidth / toheight; 

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                            y = 0; 

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                            x = (originalImage.Width - ow) / 2; 

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                        } 

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                        else

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                        { 

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                            ow = originalImage.Width; 

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                            oh = originalImage.Width * height / towidth; 

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                            x = 0; 

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                            y = (originalImage.Height - oh) / 2; 

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                        } 

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                        break; 

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                    default: 

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                        break; 

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                } 

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                //新建一个bmp图片 

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                System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight); 

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                //新建一个画板 

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                System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap); 

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                //设置高质量插值法 

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                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; 

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                //设置高质量,低速度呈现平滑程度 

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                g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; 

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                //清空画布并以透明背景色填充 

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                g.Clear(System.Drawing.Color.Transparent); 

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                //在指定位置并且按指定大小绘制原图片的指定部分 

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                g.DrawImage(originalImage, new System.Drawing.Rectangle(0, 0, towidth, toheight), 

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                    new System.Drawing.Rectangle(x, y, ow, oh), 

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                    System.Drawing.GraphicsUnit.Pixel); 

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                try

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                { 

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                    //以jpg格式保存缩略图 

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                    bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg); 

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                } 

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                catch (System.Exception e) 

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                { 

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                    HttpContext.Current.Response.Write(e.ToString() + thumbnailPath); 

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                } 

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                finally

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                { 

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                    originalImage.Dispose(); 

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                    bitmap.Dispose(); 

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                    g.Dispose(); 

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                } 

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            } 

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        } 

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        catch

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        { 

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        } 

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    } 

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    #endregion 

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}

2.相关方法

01
//根据url获取文件名 

02
public static string GetUrlFileName(string url) 

03
    { 

04
        if (string.IsNullOrEmpty(url)) 

05
        { 

06
            return ""; 

07
        } 

08
        string[] strs1 = url.Split(new char[] { '/' }); 

09
        return strs1[strs1.Length - 1].Split(new char[] { '?' })[0]; 

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    }