使用FileUpload控件上传图片并自动生成缩略图

1、using System;using System.Data;using System.Configuration;using System.Collections;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;public partial class upfile_upfi

2、le : System.Web.UI.Pageprotected void Page_Load(object sender, EventArgs e protected void Button1_Click(object sender, EventArgs eif (FileUpload1.HasFilestring fileContentType = FileUpload1.PostedFile.ContentType;if (fileContentType = image/bmp | fileContentType = image/gif | fileContentType = image

3、/pjpegstring name = FileUpload1.PostedFile.FileName; / 客户端文件路径FileInfo file = new FileInfo(name;string fileName = file.Name; / 文件名称string fileName_s = s_ + file.Name; / 缩略图文件名称string fileName_sy = sy_ + file.Name; / 水印图文件名称（文字）string fileName_syp = syp_ + file.Name; / 水印图文件名称（图片）string webFilePath =

4、 Server.MapPath(file/ + fileName; / 服务器端文件路径string webFilePath_s = Server.MapPath(file/ + fileName_s;/ 服务器端缩略图路径string webFilePath_sy = Server.MapPath(file/ + fileName_sy;/ 服务器端带水印图路径(文字string webFilePath_syp = Server.MapPath(file/ + fileName_syp;/ 服务器端带水印图路径(图片string webFilePath_sypf = Server.MapPa

5、th(file/shuiyin.jpg;/ 服务器端水印图路径(图片if (!File.Exists(webFilePathtryFileUpload1.SaveAs(webFilePath; / 使用 SaveAs 方法保存文件AddShuiYinWord(webFilePath, webFilePath_sy;AddShuiYinPic(webFilePath, webFilePath_syp, webFilePath_sypf;MakeThumbnail(webFilePath, webFilePath_s, 130, 130, Cut; / 生成缩略图方法Label1.Text = 提

6、示：文件“ + fileName + ”成功上传，并生成“ + fileName_s + ”缩略图，文件类型为： + FileUpload1.PostedFile.ContentType + ，文件大小为： + FileUpload1.PostedFile.ContentLength + B;catch (Exception exLabel1.Text = 提示：文件上传失败，失败原因： + ex.Message;elseLabel1.Text = 提示：文件已经存在，请重命名后上传;elseLabel1.Text = 提示：文件类型不符;/ / 生成缩略图/ / 源图路径（物理路径）/ 缩略

7、图路径（物理路径）/ 缩略图宽度/ 缩略图高度/ 生成缩略图的方式 public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string modeSystem.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath;int towidth = width;int toheight = height;int x = 0;int y = 0;int

8、ow = originalImage.Width;int oh = originalImage.Height;switch (modecase HW:/指定高宽缩放（可能变形） break;case W:/指定宽，高按比例 toheight = originalImage.Height * width / originalImage.Width;break;case H:/指定高，宽按比例towidth = originalImage.Width * height / originalImage.Height;break;case Cut:/指定高宽裁减（不变形） if (doubleorig

9、inalImage.Width / (doubleoriginalImage.Height (doubletowidth / (doubletoheightoh = originalImage.Height;ow = originalImage.Height * towidth / toheight;y = 0;x = (originalImage.Width - ow / 2;elseow = originalImage.Width;oh = originalImage.Width * height / towidth;x = 0;y = (originalImage.Height - oh

10、 / 2;break;default:break;/新建一个bmp图片System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight;/新建一个画板System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap;/设置高质量插值法g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;/设置高质量,低速度呈现平滑程度g.SmoothingMode = Sy

11、stem.Drawing.Drawing2D.SmoothingMode.HighQuality;/清空画布并以透明背景色填充g.Clear(System.Drawing.Color.Transparent;/在指定位置并且按指定大小绘制原图片的指定部分g.DrawImage(originalImage, new System.Drawing.Rectangle(0, 0, towidth, toheight,new System.Drawing.Rectangle(x, y, ow, oh,System.Drawing.GraphicsUnit.Pixel;try/以jpg格式保存缩略图bi

12、tmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg;catch (System.Exception ethrow e;finallyoriginalImage.Dispose(;bitmap.Dispose(;g.Dispose(;/ / 在图片上增加文字水印/ / 原服务器图片路径/ 生成的带文字水印的图片路径protected void AddShuiYinWord(string Path, string Path_systring addText = 测试水印;System.Drawing.Image imag

13、e = System.Drawing.Image.FromFile(Path;System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image;g.DrawImage(image, 0, 0, image.Width, image.Height;System.Drawing.Font f = new System.Drawing.Font(Verdana, 16;System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Blue;g

14、.DrawString(addText, f, b, 15, 15;g.Dispose(;image.Save(Path_sy;image.Dispose(;/*/ / 在图片上生成图片水印/ / 原服务器图片路径/ 生成的带图片水印的图片路径/ 水印图片路径protected void AddShuiYinPic(string Path, string Path_syp, string Path_sypfSystem.Drawing.Image image = System.Drawing.Image.FromFile(Path;System.Drawing.Image copyImage = System.Drawing.Image.FromFile(Path_sypf;System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image;g.DrawImage(copyImage, new System.Drawing.R