C#时间进行比较

  DateTime   t1   =   new   DateTime(100);   
  DateTime   t2   =   new   DateTime(20);   
  //t1比t2大    
  if   (DateTime.Compare(t1,   t2)   >     0)   Console.WriteLine("t1   >   t2");  
  //t1和t2相等
  if   (DateTime.Compare(t1,   t2)   ==   0)   Console.WriteLine("t1   ==   t2");   
  //t1比t2小  
  if   (DateTime.Compare(t1,   t2)   <     0)   Console.WriteLine("t1   <   t2");