c# - 如何比较月年与 DateParse

Question

我必须检查日期(月-年)是否小于实际日期。

我知道如何只用一个月或一年来做，比如

DateTime.Parse(o.MyDate).Month <= DateTime.Now.Month

或

DateTime.Parse(o.MyDate).Year <= DateTime.Now.Year

但是我如何直接检查 month-year 是否小于 now.month-now.year？

编辑

例如，我要做的是检查 10-2011 (DateTime.Now.Month-DateTime.Now.Year) 是否在 01-2011 和 04-2012 之间...

Answer 1

如果年份相同，比较月份，如果年份不同，你的年份一定比现在小:

var yourDate = ...;
if((yourDate.Year == DateTime.Now.Year && yourDate.Month < DateTime.Now.Month)
   || yourDate.Year < DateTime.Now.Year)
{
    // yourDate is smaller than todays month.
}

更新:

要检查 yourDate 是否在特定时间范围内，请使用:

var yourDate = ...;
var lowerBoundYear = 2011;
var lowerBoundMonth = 1;
var upperBoundYear = 2012;
var upperBoundMonth = 4;

if(((yourDate.Year == lowerBoundYear && yourDate.Month >= lowerBoundMonth) || 
    yourDate.Year > lowerBoundYear
   ) &&
   ((yourDate.Year == upperBoundYear && yourDate.Month <= upperBoundMonth) ||
    yourDate.Year < lowerBoundYear
   ))
{
    // yourDate is in the time range 01/01/2011 - 30/04/2012
    // if you want yourDate to be in the range 01/02/2011 - 30/04/2012, i.e. 
    // exclusive lower bound, change the >= to >.
    // if you want yourDate to be in the range 01/01/2011 - 31/03/2012, i.e.
    // exclusive upper bound, change the <= to <.
}