Question

我有一个非常简单的程序：

Option Strict On
Imports System
Imports Microsoft.VisualBasic

Module Program
    Sub Main(args As String())
        Dim birthDate As DateTime = DateTime.Now.AddYears(-1)
        Dim dateDifference As DateTime = DateDiff(DateInterval.Month, DateTime.Now, birthDate)
        Console.WriteLine(dateDifference.ToString)
        Console.ReadLine()
    End Sub
End Module

尝试使用DateDiff给出了错误＆＃34;未声明DateDiff。由于它的保护级别，它可能无法访问。＆＃34;我所看到的一切都说DateDiff应该在Microsoft.VisualBasic命名空间中。我可以看到，我已经导入了该命名空间。我甚至在解决方案资源管理器中添加了对它的引用。非常令人沮丧，有人请让我知道我做错了什么吗？

Answer 1

您的代码中存在两个问题

DateDiff返回一个长整数。您已分配日期时间。
您的通话中有DateTime.Now-birthDate而不是DateTime.Now，birthDate

Sub Main(args As String())
  Dim birthDate As DateTime = DateTime.Now.AddYears(-1)
  Dim dateDifference As Long = DateDiff(DateInterval.Month, DateTime.Now, birthDate)
  Console.WriteLine(dateDifference.ToString)
  Console.ReadLine()
End Sub

Answer 2

Option Strict On
Imports System
Imports Microsoft.VisualBasic

Module Program
    Sub Main(args As String())
        Dim birthDate As DateTime = DateTime.Now.AddYears(-1)
        Dim dateDifference As Long = DateDiff(DateInterval.Month, DateTime.Now, birthDate)
        Console.WriteLine(dateDifference.ToString)
        Console.ReadLine()
    End Sub
End Module

这很有效。

DateDiff没有显示

2 个答案: