计算距离当前时间

　　public string DiffTime(DateTime time)
{
TimeSpan nowTime = new TimeSpan(DateTime.Now.Ticks);

TimeSpan releaseTime = new TimeSpan(time.Ticks);

TimeSpan diff = nowTime.Subtract(releaseTime).Duration();
if (diff.Days > 0)
{
return diff.Days + "天前";
}
else if (diff.Hours > 0)
{
return diff.Hours + "小时前";
}
else if (diff.Minutes > 0)
{
return diff.Minutes + "分钟前";
}
else// if (diff.Seconds > 0)
{
return diff.Seconds + "秒前";
}
}