static void Main(string [] args)
{
    string url1 = "http://my.oschina.net/js/ke/plugins/emoticons/{0}.gif" ;
    for(int i=0; i<135; i++)
    {
        string url = string.Format(url1, i);
        WebRequest request = WebRequest .Create(url);
        WebResponse response = request.GetResponse();
        Stream reader = response.GetResponseStream();
        FileStream writer = new FileStream (@"E:\临时测试\ConsoleApplication2\新建文件夹\" + i.ToString() + ".gif", FileMode.OpenOrCreate, FileAccess.Write);
        byte[] buff = new byte[512];
        int c = 0; //实际读取的字节数
        while ((c = reader.Read(buff, 0, buff.Length)) > 0)
        {
            writer.Write(buff, 0, c);
        }
        writer.Close();
        writer.Dispose();
        reader.Close();
        reader.Dispose();
        response.Close();
    }
    Console.WriteLine( "下载完成.." );
}