C# DateTime.AddDays()用法及代碼示例

此方法用於返回新的DateTime，該日期將指定的天數添加到此實例的值中。

用法:

public DateTime AddDays (double value);

在這裏，該值是整天和小數天數。值參數可以為負或正。

返回值：此方法返回一個對象，其值是此實例表示的日期和時間與value表示的天數之和。

異常：如果生成的DateTime小於MinValue或大於MaxValue，則此方法將提供ArgumentOutOfRangeException。

以下示例程序旨在說明DateTime.AddDays(Double)方法的用法：

示例1:

// C# program to demonstrate the 
// DateTime.AddDays(Double) Method 
using System; 
using System.Globalization; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        try { 
  
            // creating object of DateTime 
            DateTime date1 = new DateTime(2010, 1, 1, 
                                           8, 0, 15); 
  
            // adding the 36 days 
            // using AddDays() method; 
            DateTime date2 = date1.AddDays(36); 
  
            // Display the date1 
            System.Console.WriteLine("DateTime before "+ 
                      "operation: {0:y} {0:dd}", date1); 
  
            // Display the date2 
            System.Console.WriteLine("\nDateTime after"+ 
                     " operation: {0:y} {0:dd}", date2); 
        } 
  
        catch (ArgumentOutOfRangeException e)  
        { 
            Console.Write("Exception Thrown: "); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
}

輸出：

DateTime before operation: 2010 January 01

DateTime after operation: 2010 February 06

示例2:對於ArgumentOutOfRangeException

// C# program to demonstrate the 
// DateTime.AddDays(Double) Method 
using System; 
using System.Globalization; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        try { 
  
            // creating object of DateTime and 
            // initialize with MinValue 
            DateTime date1 = DateTime.MaxValue; 
  
            // Display the date1 
            Console.WriteLine("DateTime before "+ 
               "operation: {0:y} {0:dd}", date1); 
  
            // adding the TimeSpan of 36 days 
            // using Add() method; 
            System.DateTime date2 = date1.AddDays(36); 
  
            // Display the date2 
            System.Console.WriteLine("\nDateTime after "+ 
                       "operation: {0:y} {0:dd}", date2); 
        } 
  
        catch (ArgumentOutOfRangeException e)  
        { 
            Console.WriteLine("\nThe resulting DateTime is "+ 
                       "greater than the DateTime.MaxValue "); 
  
            Console.Write("Exception Thrown: "); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
}

輸出：

DateTime before operation: 9999 December 31

The resulting DateTime is greater than the DateTime.MaxValue 
Exception Thrown: System.ArgumentOutOfRangeException

注意：

此方法不會更改此DateTime的值。而是返回一個新的DateTime，其值是此操作的結果。
值的小數部分是一分鍾的小數部分。例如，7.5等於7分鍾，30秒，0毫秒和0個滴答。
value參數四舍五入到最接近的毫秒數。

參考：

https://docs.microsoft.com/en-us/dotnet/api/system.datetime.adddays?view=netframework-4.7.2

相關用法

注：本文由純淨天空篩選整理自RohitPrasad3大神的英文原創作品 DateTime.AddDays() Method in C#。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。