Question

我想计算今天从c＃开始的最后半年。

我场景的前半年是01/01 / - 06/30 /。我的场景中的第二个半年是07/01 / - 12/31 /。

您如何使用DateTime计算？

示例：今天是2014年3月15日 - ＆gt;上半年：07/01/2013 - 12/31/2013

示例：今天是2014年7月15日 - ＆gt;上半年：01/01/2014 - 06/30/2014。

提前致谢！ ; - ）

Answer 1

您只需要查看6个月前的月份，并确定其中的一半：

DateTime start, end;

var date = DateTime.Today.AddMonths(-6);
var month = date.Month;
var year = date.Year;
if (month <= 6) {
    start = new DateTime(year, 1, 1);
    end = new DateTime(year, 6, 30);
} else {
    start = new DateTime(year, 7, 1);
    end = new DateTime(year, 12, 31);
}

Answer 2

如果你检查月份是否大于6，只需要一个if else，并创建如下的日期范围。

DateTime today = DateTime.Today;
if(today.Month > 6)
    Console.WriteLine(new DateTime(today.Year,1,1).ToShortDateString() + "->" + 
                      new DateTime(today.Year,6,30).ToShortDateString());
else
    Console.WriteLine(new DateTime(today.Year-1,6,1).ToShortDateString() + "->" + 
                      new DateTime(today.Year-1,12,31).ToShortDateString());

Answer 3

你可以这样做：

var start = new DateTime(
    DateTime.Today.Year,
    1 + 6 * (DateTime.Today.Month / 7),
    1);
var end = new DateTime(
    DateTime.Today.Year + DateTime.Today.Month / 7,
    7 - 6 * (DateTime.Today.Month / 7),
    1).AddDays(-1.0);

Answer 4

退一天，直到你遇到第12个月或第06个月

// get first of this month
DateTime prev =  new DAteTime( DateTime.Today.Year, DateTime.Today.Month, 1);

bool found = false;
while(found == false){
    prev = prev.AddDays(-1);
    if(prev.Month == 12)
        found = true;
    if(prev.Month == 6)
        found = true
} 

// then when found, count back 6 months from that

DateTime start = prev.AddMonths(-6)

// then get the first of that month
start = new DateTime(start.Year, start.Month, 1);

Answer 5

请找到以下代码段。

            string firstHalf = "30/06/";

            int currentYear = DateTime.Now.Date.Year;

            if (DateTime.Now.Date > Convert.ToDateTime(firstHalf + Convert.ToString(currentYear)).Date)
            {
                MessageBox.Show("Last Half Year : " + "01/01/" + Convert.ToString(currentYear) + " to  30/06/" + Convert.ToString(currentYear));
            }
            else
                MessageBox.Show("Last Half Year : " + "01/07/" + Convert.ToString(currentYear - 1) + " to  31/12/" + Convert.ToString(currentYear - 1));

Answer 6

谢谢你们。我更喜欢GvS的答案。

我这样做：

            var halfyear = (float)DateTime.Today.Month / 6;
            var halfyearModulo = halfyear % 1;

            if (halfyearModulo == 0)
                halfyear--;

            var minimumDate = new DateTime(DateTime.Today.Year, ((int)halfyear * 6) + 1, 1).AddMonths(-6);
            var maximumDate = minimumDate.AddMonths(6);

但我认为GvSs更好。

C＃计算当前半年

6 个答案: