C# 上傳圖片

介面：

前台所用控制項：一個FileUpload用來瀏覽，一個Button用來上傳，一個Image用來顯示上傳的圖片

前台代碼：

<div>        <asp:FileUpload ID="FileUpimage" runat="server" />        <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="上傳" />        <asp:Image ID="Image1" runat="server" ImageUrl="~/image/save.png" Visible="False" /></div>

後台代碼：

        /// <summary>        /// 上傳        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        protected void Button1_Click(object sender, EventArgs e)        {            //判斷上傳控制項中是否有值              if (FileUpimage.HasFile == false)              {                  Response.Write("<script>alert('請指定上傳的頭像')</script>");            }              else              {                  string fType = FileUpimage.PostedFile.ContentType;//擷取映像的類型                  if (fType == "image/bmp" || fType == "image/gif" || fType == "image/pjpeg" || fType == "image/jpeg" || fType == "image/x-png" || fType == "image/png")                  {                      //擷取檔案資訊                      FileInfo file = new FileInfo(FileUpimage.PostedFile.FileName);                      ///隨機資料                      Guid guid = Guid.NewGuid();                      string stamp = guid.ToString("N");                      //產生隨機數                      Random aa=new Random();                      string  number=aa.Next(10000).ToString();                      //原始圖片儲存路徑                      string path = "~/Files/" + stamp + ".gif";                      //縮圖儲存路徑                      string spath = "~/Files/" + number + ".gif";                      try                      {                          //原始圖片儲存                          FileUpimage.SaveAs(Server.MapPath(path));                          //縮圖儲存                          MakeThumbImage(Server.MapPath(path), Server.MapPath(spath), 200, 100);                          //給隱藏的圖片控制項賦值並顯示                          Image1.Visible = true;                          Image1.ImageUrl = spath;                        Response.Write("<script>alert('上傳成功')</script>");                    }                      catch                      {                          Response.Write("<script>alert('上傳失敗')</script>");                    }                  }                  else                  {                       Response.Write("<script>alert('上傳頭像格式不正確')</script>");                }              }          }    ///<summary>      ///方法名稱：MakeThumbImage      ///內容摘要：產生縮圖      /// </summary>      /// <param name="sPath">源圖路徑（實體路徑）</param>      /// <param name="stPath">縮圖路徑（實體路徑）</param>      /// <param name="nWidth">縮圖寬度</param>      /// <param name="nHeight">縮圖高度</param>      private void MakeThumbImage(string sPath, string stPath, int nWidth, int nHeight)      {          System.Drawing.Image sImage = System.Drawing.Image.FromFile(sPath);          int tw = nWidth;          int th = nHeight;          //原始圖片的寬度和高度          int sw = sImage.Width;          int sh = sImage.Height;          if (sw > tw)          {              sw = tw;          }          if (sh > th)          {              sh = th;          }          System.Drawing.Bitmap objPic, objNewPic;  //映像對象        objPic = new System.Drawing.Bitmap(sPath);        objNewPic = new System.Drawing.Bitmap(objPic, sw, sh);  //使用指定的大小初始化objNewPic        objNewPic.Save(stPath);          sImage.Dispose();  //釋放資源        objPic.Dispose();          objNewPic.Dispose();      }