代码：

/// 
/// Http下载文件/// 
public static string HttpDownloadFile(string url, string path){    // 设置参数    HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;    //发送请求并获取相应回应数据    HttpWebResponse response = request.GetResponse() as HttpWebResponse;    //直到request.GetResponse()程序才开始向目标网页发送Post请求    Stream responseStream = response.GetResponseStream();    //创建本地文件写入流    Stream stream = new FileStream(path, FileMode.Create);    byte[] bArr = new byte[1024];    int size = responseStream.Read(bArr, 0, (int)bArr.Length);    while (size > 0)    {        stream.Write(bArr, 0, size);        size = responseStream.Read(bArr, 0, (int)bArr.Length);    }    stream.Close();    responseStream.Close();    return path;}