一个定义在类中的上传图片函数

using System;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls; 

 

 

/**//// <summary>
  /// 上传图片后并把图片处理成适当大小,是横图片则处理成宽为maxSize,
  /// 是竖图片的处理成高为maxHSize,比例小于maxSize或maxHSize则不作处理
  /// </summary>
  /// <param name="page">页面对象,为了在方法中可以使用Page对象</param>
  /// <param name="FilePic">上传文件框,用于选择图片</param>
  /// <param name="imgLogo">image控件,用于显示上传后的图片</param>
  /// <param name="txtPath">text文本框,用来保存上传图片的路径</param>
  /// <param name="maxSize">最大图片宽度</param>
  /// <param name="maxHSize">最大图片高度</param>
  /// <param name="srcpath">图片的保存路径</param>
public static void UploadImage(System.Web.UI.Page page,ref System.Web.UI.HtmlControls.HtmlInputFile FilePic,ref System.Web.UI.WebControls.Image imgLogo,ref System.Web.UI.WebControls.TextBox txtPath,int maxSize,int maxHSize,string srcpath)
  {
   if(FilePic.PostedFile.FileName!=null)
   {
    try
    {
     string dtime=DateTime.Now.ToString("yyMMddHHmmss");
     if(!(FilePic.PostedFile.ContentLength>0))
     {
      page.Response.Write("<script> {alert(\'请选择要上传的图片!\');}<"+"/script>");
      page.Response.Write("<script>history.go(-1)<"+"/script>");
     }
     else
     {
      //int maxSize=150;//图片的长宽最大像素
      string strtype=FilePic.PostedFile.FileName.Substring(FilePic.PostedFile.FileName.LastIndexOf('.'));
      //string srcpath="UploadFiles/";//存储图片的文件夹路径
      string path=page.Server.MapPath(srcpath+dtime+strtype);
      string imgname=dtime+strtype;
      System.Drawing.Image bigimage=System.Drawing.Image.FromStream(FilePic.PostedFile.InputStream);
      System.Drawing.Bitmap output=new System.Drawing.Bitmap(bigimage);
      decimal width=bigimage.Width;
      decimal height=bigimage.Height;
      int newwidth,newheight;
      if(width>=height)
      {
       if(width>maxSize)
       {
        newwidth=maxSize;
        newheight=(int)(height/width*maxSize);
       }
       else
       {
        newwidth=(int)width;
        newheight=(int)height;
       }
      }
      else
      {
       if(height>maxHSize)
       {
        newheight=maxHSize;
        newwidth=(int)(width/height*maxHSize);
       }
       else
       {
        newwidth=(int)width;
        newheight=(int)height;
       }
      }
      System.Drawing.Image smallimage=output.GetThumbnailImage(newwidth,newheight,null, IntPtr.Zero);
      switch(strtype)
      {
       case ".jpg":
        smallimage.Save(path,System.Drawing.Imaging.ImageFormat.Jpeg);
        break;
       case ".gif":
        smallimage.Save(path,System.Drawing.Imaging.ImageFormat.Gif);
        break;
       case ".ico":
        smallimage.Save(path,System.Drawing.Imaging.ImageFormat.Icon);
        break;
       case ".bmp":
        smallimage.Save(path,System.Drawing.Imaging.ImageFormat.MemoryBmp);
        break;
       case ".png":
        smallimage.Save(path,System.Drawing.Imaging.ImageFormat.Png);
        break;
       case ".tif":
        smallimage.Save(path,System.Drawing.Imaging.ImageFormat.Tiff);
        break;
      }
      imgLogo.Visible=true;
      imgLogo.ImageUrl=srcpath+dtime+strtype;
      txtPath.Text=srcpath+dtime+strtype;
     }
    }
    catch(Exception ex)
    {
     page.Response.Redirect("~/Manage/ErrorPage.aspx?ErrorUrl="
      + YLWeb.Class.WebSystem.RedirectErrorUrl(page.Request.RawUrl)
      + "&ErrorMessage=" + ex.Message.Replace("\n"," "));
    }
   }
  }