此方法用于返回一个新的DateTimeOffset对象，该对象将指定天数的整数和小数天加到该实例的值上。
Syntax: public DateTimeOffset AddDays (double days);
Here, it takes a number of whole and fractional days.
Return Value: This method returns an object whose value is the sum of the date and time represented by the current DateTimeOffset object and the number of days represented by days.
Exception: This method will give ArgumentOutOfRangeException if the resulting DateTimeOffset value is less than MinValue or the resulting DateTimeOffset value is greater than MaxValue.
下面的程序说明了DateTimeOffset.AddDays(Double)方法的用法：
范例1：
// C# program to demonstrate the
// DateTimeOffset.AddDays(Double)
// Method
using System;
using System.Globalization;
class GFG {
// Main Method
public static void Main()
{
try {
// creating object of DateTimeOffset
DateTimeOffset offset = new DateTimeOffset(2007, 6, 1, 7, 55, 0,
new TimeSpan(-5, 0, 0));
// adding a specified number of whole
// and fractional days to the value
// of this instance using AddDays(Double)
// method
DateTimeOffset value = offset.AddDays(10);
// Display the time
Console.WriteLine("DateTimeOffset is {0}", value);
}
catch (ArgumentOutOfRangeException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
}
}
输出：
DateTimeOffset is 06/11/2007 07:55:00 -05:00
示例2：对于ArgumentOutOfRangeException
// C# program to demonstrate the
// DateTimeOffset.AddDays(Double)
// Method
using System;
using System.Globalization;
class GFG {
// Main Method
public static void Main()
{
try {
// creating object of DateTimeOffset
DateTimeOffset offset = DateTimeOffset.MaxValue;
// adding a specified number of whole and
// fractional days to the value of this instance.
// using AddDays(Double) method;
DateTimeOffset value = offset.AddDays(10);
// Display the time
Console.WriteLine("DateTimeOffset is {0}", value);
}
catch (ArgumentOutOfRangeException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
}
}
输出：
Exception Thrown: System.ArgumentOutOfRangeException
参考：
- https://docs.microsoft.com/zh-cn/dotnet/api/system.datetimeoffset.adddays?view=netframework-4.7.2