时间比较方法DateTime.Compare

格式：DateTime.Compare(datetime1, datetime2)

参数为时间格式，为第一个参数比较第二个参数，返回小于0的值，等于0或大于0的值。

string st1 = "12:13";
string st2 = "14:13";
DateTime t1 = Convert.ToDateTime(st1);
Console.WriteLine(t1);  //20186/6 下午 12:12:00
DateTime t2 = Convert.ToDateTime(st2);
Console.WriteLine(t2);  //20186/6 下午 02:14:00
DateTime t3 = DateTime.Now;
Console.WriteLine(t3);
if (DateTime.Compare(t1, t2) > 0) Console.WriteLine(st1+">"+st2);
else if (DateTime.Compare(t1, t2) == 0) Console.WriteLine(st1+"="+st2);
else Console.WriteLine(st1+"<"+st2);

if (DateTime.Compare(t1, t3) > 0) Console.WriteLine("rn"+st1 + ">" + t3.ToString());
else if (DateTime.Compare(t1, t3) == 0) Console.WriteLine("rn" + st1 + "=" + t3.ToString());
else Console.WriteLine("rn" + st1 + "<" + t3.ToString());