asp.net实现生成缩略图及给原始图加水印的方法示例

本文实例讲述了asp.net实现生成缩略图及给原始图加水印的方法。分享给大家供大家参考，具体如下：

using System.IO;
using System.Drawing.Imaging;
private void Button1_ServerClick(object sender,System.EventArgs e) 
{
  Graphics g=null;
  System.Drawing.Image upimage=null;
  System.Drawing.Image thumimg=null;
  System.Drawing.Image simage=null;
  Bitmap outputfile=null;
  try 
  {
    string extension = Path.GetExtension(File1.PostedFile.FileName).ToUpper();
    string filename = DateTime.Now.ToString("yyyyMMddhhmmss");
    string smallpath = Server.MapPath(".")+"/smallimg/";
    string bigpath = Server.MapPath(".")+"/bigimg/";
    int width,height,newwidth,newheight;
    System.Drawing.Image.GetThumbnailImageAbort callb =new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
    if(!Directory.Exists(smallpath))
    Directory.CreateDirectory(smallpath);
    if(!Directory.Exists(bigpath))
    Directory.CreateDirectory(bigpath);
    Stream upimgfile = File1.PostedFile.InputStream;
    string simagefile = Server.MapPath("a8logo.jpg"); //要加水印的文件
    simage=System.Drawing.Image.FromFile(simagefile);
    upimage= System.Drawing.Image.FromStream(upimgfile); //上传的图片
    width = upimage.Width;
    height = upimage.Height;
    if(width>height) 
    {
      newwidth=200;
      newheight =(int)((double)height/(double)width * (double)newwidth);
    } else 
    {
      newheight=200;
      newwidth=(int)((double)width/(double)height * (double)newheight);
    }
    thumimg = upimage.GetThumbnailImage(newwidth,newheight,callb,IntPtr.Zero);
    outputfile=new Bitmap(upimage);
    g=Graphics.FromImage(outputfile);
    g.DrawImage(simage,new Rectangle(upimage.Width-simage.Width,upimage.Height-simage.Height,upimage.Width,upimage.Height),upimage.Height,GraphicsUnit.Pixel);
    string newpath = bigpath + filename + extension; //原始图路径
    string thumpath = smallpath + filename + extension; //缩略图路径
    outputfile.Save(newpath);
    thumimg.Save(thumpath);
    outputfile.Dispose();
  }
  catch(Exception ex) 
  {
    throw ex;
  }
  finally 
  {
    if(g!=null)
    g.Dispose();
    if(thumimg!=null)
    thumimg.Dispose();
    if(upimage!=null)
    upimage.Dispose();
    if(simage!=null)
    simage.Dispose();
  }
}
public bool ThumbnailCallback() 
{
  return false;
}

更多关于asp.net相关内容感兴趣的读者可查看本站专题：《asp.net字符串操作技巧汇总》、《asp.net操作XML技巧总结》、《asp.net操作json技巧总结》、《asp.net文件操作技巧汇总》、《asp.net ajax技巧总结专题》及《asp.net缓存操作技巧总结》。

希望本文所述对大家asp.net程序设计有所帮助。

（编辑：哈尔滨站长网）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!