DateTime.DaysInMonth(Int32, Int32) 方法
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
回傳指定月份和年份的天數。
public:
static int DaysInMonth(int year, int month);public static int DaysInMonth(int year, int month);static member DaysInMonth : int * int -> intPublic Shared Function DaysInMonth (year As Integer, month As Integer) As Integer參數
- year
- Int32
年份。
- month
- Int32
月份（數字範圍從1到12）。
傳回
指定 的天monthyear數。
例如，若 month 二月等於2，則回報值為28或29，視是否 year 為閏年而定。
例外狀況
範例
以下範例示範如何利用此 DaysInMonth 方法來計算2001年7月、1998年2月（非閏年）及1996年2月（閏年）的天數。
open System
let July = 7
let Feb = 2
let daysInJuly = DateTime.DaysInMonth(2001, July)
printfn $"{daysInJuly}"
// daysInFeb gets 28 because the year 1998 was not a leap year.
let daysInFeb = DateTime.DaysInMonth(1998, Feb)
printfn $"{daysInFeb}"
// daysInFebLeap gets 29 because the year 1996 was a leap year.
let daysInFebLeap = DateTime.DaysInMonth(1996, Feb)
printfn $"{daysInFebLeap}"
// The example displays the following output:
// 31
// 28
// 29
using System;
class Example
{
static void Main()
{
const int July = 7;
const int Feb = 2;
int daysInJuly = System.DateTime.DaysInMonth(2001, July);
Console.WriteLine(daysInJuly);
// daysInFeb gets 28 because the year 1998 was not a leap year.
int daysInFeb = System.DateTime.DaysInMonth(1998, Feb);
Console.WriteLine(daysInFeb);
// daysInFebLeap gets 29 because the year 1996 was a leap year.
int daysInFebLeap = System.DateTime.DaysInMonth(1996, Feb);
Console.WriteLine(daysInFebLeap);
}
}
// The example displays the following output:
// 31
// 28
// 29
Class Example
Public Shared Sub Main()
Const July As Integer = 7
Const Feb As Integer = 2
Dim daysInJuly As Integer = System.DateTime.DaysInMonth(2001, July)
Console.WriteLine(daysInJuly)
' daysInFeb gets 28 because the year 1998 was not a leap year.
Dim daysInFeb As Integer = System.DateTime.DaysInMonth(1998, Feb)
Console.WriteLine(daysInFeb)
' daysInFebLeap gets 29 because the year 1996 was a leap year.
Dim daysInFebLeap As Integer = System.DateTime.DaysInMonth(1996, Feb)
Console.WriteLine(daysInFebLeap)
End Sub
End Class
' The example displays the following output:
' 31
' 28
' 29
以下範例以整數陣列顯示每年每個月的天數。
using System;
using System.Globalization;
public class Example
{
public static void Main()
{
int[] years = { 2012, 2014 };
DateTimeFormatInfo dtfi = DateTimeFormatInfo.CurrentInfo;
Console.WriteLine("Days in the Month for the {0} culture " +
"using the {1} calendar\n",
CultureInfo.CurrentCulture.Name,
dtfi.Calendar.GetType().Name.Replace("Calendar", ""));
Console.WriteLine("{0,-10}{1,-15}{2,4}\n", "Year", "Month", "Days");
foreach (var year in years) {
for (int ctr = 0; ctr <= dtfi.MonthNames.Length - 1; ctr++) {
if (String.IsNullOrEmpty(dtfi.MonthNames[ctr]))
continue;
Console.WriteLine("{0,-10}{1,-15}{2,4}", year,
dtfi.MonthNames[ctr],
DateTime.DaysInMonth(year, ctr + 1));
}
Console.WriteLine();
}
}
}
// The example displays the following output:
// Days in the Month for the en-US culture using the Gregorian calendar
//
// Year Month Days
//
// 2012 January 31
// 2012 February 29
// 2012 March 31
// 2012 April 30
// 2012 May 31
// 2012 June 30
// 2012 July 31
// 2012 August 31
// 2012 September 30
// 2012 October 31
// 2012 November 30
// 2012 December 31
//
// 2014 January 31
// 2014 February 28
// 2014 March 31
// 2014 April 30
// 2014 May 31
// 2014 June 30
// 2014 July 31
// 2014 August 31
// 2014 September 30
// 2014 October 31
// 2014 November 30
// 2014 December 31
open System
open System.Globalization
let years = [| 2012; 2014 |]
let dtfi = DateTimeFormatInfo.CurrentInfo
printfn $"""Days in the Month for the {CultureInfo.CurrentCulture.Name} culture using the {dtfi.Calendar.GetType().Name.Replace("Calendar", "")} calendar\n"""
printfn $"""{"Year",-10}{"Month",-15}{"Days",4}\n"""
for year in years do
for i = 0 to dtfi.MonthNames.Length - 1 do
if not (String.IsNullOrEmpty dtfi.MonthNames[i]) then
printfn $"{year,-10}{dtfi.MonthNames[i],-15}{DateTime.DaysInMonth(year, i + 1),4}"
printfn ""
// The example displays the following output:
// Days in the Month for the en-US culture using the Gregorian calendar
//
// Year Month Days
//
// 2012 January 31
// 2012 February 29
// 2012 March 31
// 2012 April 30
// 2012 May 31
// 2012 June 30
// 2012 July 31
// 2012 August 31
// 2012 September 30
// 2012 October 31
// 2012 November 30
// 2012 December 31
//
// 2014 January 31
// 2014 February 28
// 2014 March 31
// 2014 April 30
// 2014 May 31
// 2014 June 30
// 2014 July 31
// 2014 August 31
// 2014 September 30
// 2014 October 31
// 2014 November 30
// 2014 December 31
Imports System.Globalization
Module Example
Public Sub Main()
Dim years() As Integer = { 2012, 2014 }
Dim dtfi As DateTimeFormatInfo = DateTimeFormatInfo.CurrentInfo
Console.WriteLine("Days in the Month for the {0} culture " +
"using the {1} calendar",
CultureInfo.CurrentCulture.Name,
dtfi.Calendar.GetType.Name.Replace("Calendar", ""))
Console.WriteLine()
Console.WriteLine("{0,-10}{1,-15}{2,4}", "Year", "Month", "Days")
Console.WriteLine()
For Each [year] As Integer In years
For ctr As Integer = 0 To dtfi.MonthNames.Length - 1
If String.IsNullOrEmpty(dtfi.MonthNames(ctr)) Then
Continue For
End If
Console.WriteLine("{0,-10}{1,-15}{2,4}", [year],
dtfi.MonthNames(ctr),
DateTime.DaysInMonth([year], ctr + 1))
Next
Console.WriteLine()
Next
End Sub
End Module
' The example displays the following output:
' Days in the Month for the en-US culture using the Gregorian calendar
'
' Year Month Days
'
' 2012 January 31
' 2012 February 29
' 2012 March 31
' 2012 April 30
' 2012 May 31
' 2012 June 30
' 2012 July 31
' 2012 August 31
' 2012 September 30
' 2012 October 31
' 2012 November 30
' 2012 December 31
'
' 2014 January 31
' 2014 February 28
' 2014 March 31
' 2014 April 30
' 2014 May 31
' 2014 June 30
' 2014 July 31
' 2014 August 31
' 2014 September 30
' 2014 October 31
' 2014 November 30
' 2014 December 31
備註
即使格里曆不是當前文化的現行曆法，該 DaysInMonth 方法總是將 month 和 year 解釋為格里曆的月份和年份。 要取得特定月份的天數，請呼叫該曆法的方法 GetDaysInMonth 。
