转换时间为 “XX分钟之前”

public static string getTimeAgo(string strDate)
    {
        string strTime = string.Empty;
        if (clsCommon.IsDate(strDate))
        {
            TimeSpan t = DateTime.UtcNow - Convert.ToDateTime(strDate);
            double deltaSeconds = t.TotalSeconds;

            double deltaMinutes = deltaSeconds / 60.0f;
            int minutes;

            if (deltaSeconds < )
            {
                return "当前";
            }
            else if (deltaSeconds < )
            {
                return Math.Floor(deltaSeconds) + " 秒之前";
            }
            else if (deltaSeconds < )
            {
                return "分钟之前";
            }
            else if (deltaMinutes < )
            {
                return Math.Floor(deltaMinutes) + " minutes ago";
            }
            else if (deltaMinutes < )
            {
                return "An hour ago";
            }
            else if (deltaMinutes < ( * ))
            {
                minutes = (int)Math.Floor(deltaMinutes / );
                return minutes + " hours ago";
            }
            else if (deltaMinutes < ( *  * ))
            {
                return "Yesterday";
            }
            else if (deltaMinutes < ( *  * ))
            {
                minutes = (int)Math.Floor(deltaMinutes / ( * ));
                return minutes + " days ago";
            }
            else if (deltaMinutes < ( *  * ))
            {
                return "Last week";
            }
            else if (deltaMinutes < ( *  * ))
            {
                minutes = (int)Math.Floor(deltaMinutes / ( *  * ));
                return minutes + " weeks ago";
            }
            else if (deltaMinutes < ( *  * ))
            {
                return "Last month";
            }
            else if (deltaMinutes < ( *  * 365.25))
            {
                minutes = (int)Math.Floor(deltaMinutes / ( *  * ));
                return minutes + " months ago";
            }
            else if (deltaMinutes < ( *  * ))
            {
                return "Last year";
            }

            minutes = (int)Math.Floor(deltaMinutes / ( *  * ));
            return minutes + " years ago";
        }
        else
        {
            return "";
        }
    }

调用方法：
getTimeAgo(DateTime.Now.ToString());