I have a date and I need to populate a drop-down with the months/years between that date and today. For instance, if that date is 10/14/2010 then the drop-down should contain October 2010, November 2010, December 2010, January 2011.
The way I'm thinking of doing this is to pass that date to a function, loop from today backwards step 1 month while adding each month to 开发者_如何学编程a collection until we reach that date and finally return a collection of strings. Then, populate the drop-down control on page load. Finally, use some ajax with a page method to parse back the string and trigger a partial page reload.
I'm just wondering if there's an easy way to do it.
Thanks.
Maybe you can try this:
static IEnumerable<DateTime> monthsBetween(DateTime startDate, DateTime endDate)
{
return Enumerable.Range(0, (endDate.Year - startDate.Year) * 12 + (endDate.Month - startDate.Month + 1))
.Select(m => new DateTime(startDate.Year, startDate.Month, 1).AddMonths(m));
}
This will not give you the result in the exact format that you want, but you get the drift. :)
You can do something like this which is pretty much what you described except counting forward:
private string[] FillDropDownWithDates(DateTime dt)
{
DateTime dtnow = DateTime.Now;
List<string> values = new List<string>();
if ( (dt <= dtnow))
{
values.Add(String.Format("{0:y}", dt));
}
while ( (dt = dt.AddMonths(1)) <= dtnow || ( dt.Month == dtnow.Month && dt.Year == dtnow.Year) )
{
values.Add(String.Format("{0:y}", dt)); // "March, 2008" YearMonth
}
return values.ToArray();
}
public static List<string> GetMonths(DateTime StartDate)
{
List<string> MonthList = new List<string>();
DateTime ThisMonth = DateTime.Now.Date;
while (ThisMonth.Date > StartDate.Date)
{
MonthList.Add(ThisMonth.ToString("MMMM") + " " + ThisMonth.Year.ToString());
ThisMonth = ThisMonth.AddMonths(-1);
}
return MonthList;
}
For Year,
public static IEnumerable<int> Range (int start, int count)
{
int end = start + count;
for (int i = start; i < end; i++)
yield return i;
}
var startYear = 2000;
YearDropDownList.ItemsSource= Enumerable.Range(startYear, 2050 - startYear + 1);
For Month, An enumerable list with .ToString("MMMM") format.
This is how I got a 12 month/year. Hope the code helps.
public IEnumerable<SelectListItem> Additional12Months {
get
{
return Enumerable.Range(12, 12).Select(i => new SelectListItem { Value = DateTime.Now.AddMonths(-(i)).ToShortDateString(), Text = DateTime.Now.AddMonths(-(i)).ToString("MMM-yyyy") }).ToList();
}
}
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