精确到毫秒
string timestamp = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds().ToString();
/// <summary>
/// 获取时间戳
/// </summary>
/// <returns></returns>
public static string GetTimeStamp()
{
TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
return Convert.ToInt64(ts.TotalMilliseconds).ToString();
}