C#日期相减得秒数、分钟数、小时数

两种日期格式 yyyyMMddHHmmss、yyyy-MM-dd HH:mm:ss

string date1 = DateTime.Now.ToString("yyyyMMddHHmmss");
string date2 = DateTime.Now.AddHours(1).ToString("yyyyMMddHHmmss");
string date3 = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
string date4 = DateTime.Now.AddHours(1).ToString("yyyy-MM-dd HH:mm:ss");

//分钟数
int op1 = Convert.ToInt32((DateTime.ParseExact(date2, "yyyyMMddHHmmss", CultureInfo.CurrentCulture) - DateTime.ParseExact(date1, "yyyyMMddHHmmss", CultureInfo.CurrentCulture)).TotalMinutes);

int op2 = Convert.ToInt32((Convert.ToDateTime(date4) - Convert.ToDateTime(date3)).TotalMinutes);

秒、小时换成对应的
TotalSeconds、TotalHours