/// <summary>
/// 获取临时素材（原下载媒体文件）
/// </summary>
/// <param name="accessToken"></param>
/// <param name="mediaId"></param>
/// <param name="stream"></param>
public static void Get(string accessToken, string mediaId, Stream stream)
{
var url = string.Format("http://api.weixin.qq.com/cgi-bin/media/get?access_token={0}&media_id={1}",
accessToken, mediaId);
HTTPGet.Download(url, stream);
}
/// <summary>
/// 获取二维码（不需要AccessToken）
/// 错误情况下（如ticket非法）返回HTTP错误码404。
/// </summary>
/// <param name="ticket"></param>
/// <param name="stream"></param>
public static void ShowQrCode(string ticket, Stream stream)
{
var url = GetShowQrCodeUrl(ticket);
HTTPGet.Download(url, stream);
}