/// 

/// 从图片地址下载图片到本地磁盘
/// 
/// 图片本地磁盘地址
/// 图片网址
/// 
public  bool DownImage(string FileName, string Url)
{
    bool Value = false;
    WebResponse response = null;
    Stream stream = null;
 
    try
    {
       HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
 
       response = request.GetResponse();
       stream = response.GetResponseStream();
 
       if (!response.ContentType.ToLower().StartsWith("text/"))
       {
          Value = SaveBinaryFile(response, FileName);
 
       }
 
    }
    catch (Exception err)
    {
       string aa = err.ToString();
    }
    return Value;
}
/// 

/// Save a binary file to disk.
/// 
/// The response used to save the file
// 将二进制文件保存到磁盘
private  bool SaveBinaryFile(WebResponse response, string FileName)
{
   bool Value = true;
   byte[] buffer = new byte[1024];
 
   try
   {
      if (File.Exists(FileName))
         File.Delete(FileName);
      Stream outStream = System.IO.File.Create(FileName);
      Stream inStream = response.GetResponseStream();
 
      int l;
      do
      {
        l = inStream.Read(buffer, 0, buffer.Length);
        if (l > 0)
          outStream.Write(buffer, 0, l);
      }
      while (l > 0);
 
      outStream.Close();
      inStream.Close();
    }
    catch
    {
      Value = false;
    }
   return Value;
}