vb.net新年第4个星期二

Question

我编写了一个支票簿应用程序，它将每月的第 4 个星期二存储在 SQLite 数据库中，当用户写支票并且今天的日期大于存储的日期时，新的第 4 个星期二日期将在数据库和存入 SS 付款的功能已加载。
在测试时我发现当年份改变时我写的第一个函数会失败。
所以我写了第二个函数来处理年的变化。
该代码似乎正在运行。我想将测试合并到一个函数中，因为代码看起来不够优雅。我将 post 下面的小测试应用程序代码。这两个函数在一个模块中。

Public Class frmStart
Dim varSearchDate As Date
Dim varFTue As Date

Private Sub frmStart_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    tbBox1.Text = "2021-12-28" ' 2021-11-23 2021-12-28 TEST DATES
End Sub

Private Sub btnADD_Click(sender As Object, e As EventArgs) Handles btnADD.Click
    varSearchDate = CDate(tbBox1.Text)
    tbAns.Text = varSearchDate.ToString("M-d-yyyy")

    Dim dateToday = Date.Today
    Dim mo As String
    mo = varSearchDate.ToString("MM")

    If dateToday > varSearchDate And CInt(mo) <> 12 Then
        varFTue = CDate(FourthTueOfNextMonth(Date.Today).ToString("yyyy-M-d"))
        MsgBox("varFTue Next Mo " & varFTue)
        tbBox2.Text = varFTue.ToString("yyyy-M-d")
        'WriteNewFourthTue()
        'gvTxType = "SS Deposit"
    ElseIf dateToday > varSearchDate And CInt(mo) = 12 Then
        varFTue = CDate(FourthTueOfNewYear(Date.Today).ToString("yyyy-M-d"))
        MsgBox("varFTue New Yr " & varFTue)
        tbBox3.Text = varFTue.ToString("yyyy-M-d")
        'WriteNewFourthTue()
        'gvTxType = "SS Deposit"
    End If
End Sub

结束Class

这两个函数和我的测试代码只使用一个函数被注释掉了

Module FunctionModule

'Function FourthTueOfNextMonth(dt As Date) As Date
'    Dim currDate = New Date(dt.Year, dt.Month, 1)
'    Dim nTuesday As Integer
'    While nTuesday < 4
'        If currDate.DayOfWeek = DayOfWeek.Tuesday Then
'            nTuesday += 1
'        End If
'        currDate = currDate.AddDays(1)
'    End While
'    If dt.Month <> 12 Then
'        Return New Date(dt.Year, dt.Month, currDate.Day - 1)
'    ElseIf dt.Month = 12 Then
'        Return New Date(dt.Year + 1, dt.Month - 11, currDate.Day - 1)
'    End If
'End Function

Function FourthTueOfNextMonth(dt As Date) As Date
    Dim currDate = New Date(dt.Year, dt.Month, 1)
    Dim nTuesday As Integer

    While nTuesday < 4
        If currDate.DayOfWeek = DayOfWeek.Tuesday Then
            nTuesday += 1
        End If
        currDate = currDate.AddDays(1)
    End While

    Return New Date(dt.Year, dt.Month, currDate.Day - 1)

End Function

Function FourthTueOfNewYear(dt As Date) As Date
    Dim currDate = New Date(dt.Year + 1, dt.Month - 11, 1)
    Dim nTuesday As Integer

    While nTuesday < 4
        If currDate.DayOfWeek = DayOfWeek.Tuesday Then
            nTuesday += 1
        End If
        currDate = currDate.AddDays(1)
    End While

    Return New Date(dt.Year + 1, dt.Month - 11, currDate.Day - 1)

End Function

模块结束

我的问题是有没有更好的方法来编写这段代码，所以我只有一个函数？

Answer 1

这是一个根据传入的日期查找下个月的第四个星期二的函数：

Function FourthTueOfNextMonth(dt As Date) As Date
    ' Start with the First Day of the Month, from the date passed in.
    ' Add one Month to that to get the first Day of the NEXT month.
    Dim currDate As Date = (New Date(dt.Year, dt.Month, 1)).AddMonths(1)
    ' Find the First Tuesday of the Month
    While currDate.DayOfWeek <> DayOfWeek.Tuesday
        currDate = currDate.AddDays(1)
    End While
    ' Add three more Weeks to jump to Fourth Tuesday
    Return currDate.AddDays(21)
End Function

请注意，该函数总是 returns 下个月的第四个星期二，并且它不会检查传入的日期是否小于包含该日期的同月的第四个星期二已通过。

vb.net新年第4个星期二

vb.net 4th Tuesday when new year

vb.net

function