DateTime endTime = new DateTime(2017, 7, 7, 11, 21, 3, 100); DateTime startTime = new DateTime(2017, 7, 7, 10, 20, 2, 200); TimeSpan temp = new TimeSpan(startTime.Ticks).Subtract(new TimeSpan(endTime.Ticks)).Duration(); double day = temp.TotalDays;//总天数 double h = temp.TotalHours;//总小时 double m = temp.TotalMinutes;//总分钟数 double s = temp.TotalSeconds;//总秒数 double ms = temp.TotalMilliseconds;//总毫秒数

double data = 1.2323;
string str1 = data.ToString("f1"); //保留一位
string str2 = String.Format("{0:F}", data);//保留两位