Validating data with Flat File Checker

Public Class DateCondition
    Inherits Condition
    Private Shadows val1 As Date
    Private Shadows val2 As Date
    Private Shadows val2_arr() As Date
    Private _wrong_format_value As String
    Private _format_index As Integer
    Private _format As String
    Sub New(ByVal value As Date, ByVal formatIndex As Integer)
        SetSecondValue(value)
        _format_index = formatIndex
    End Sub
    Sub New(ByVal value As String, ByVal formatIndex As Integer)
        SetSecondValue(CDateArray(value, DateFormats(formatIndex)))
        _format_index = formatIndex
    End Sub
    Public Sub New(ByVal value As String, ByVal format As String, ByVal operatorValue As EnumOperator)
        SetSecondValue(DateTime.ParseExact(value, format, Globalization.CultureInfo.InvariantCulture))
        _format = format
        Me.Condition = operatorValue
    End Sub

    Protected Shadows Sub SetSecondValue(ByVal value As Date)
        val2 = value
    End Sub
    Protected Shadows Sub SetSecondValue(ByVal value() As Date)
        val2_arr = value
    End Sub
    Public Overrides Property SecondValue() As String
        Get
            Select Case BenchmarkType
                Case EnumBenchmarkType.DateType
                    Return CStr(val2)
                Case EnumBenchmarkType.DateArray
                    ' Convert array to string
                    Return ""
                Case Else
                    '  Throw 
                    Return ""
            End Select
        End Get
        Set(ByVal value As String)

        End Set
    End Property

    Public Overrides Property FirstValue() As String
        Get
            If String.IsNullOrEmpty(_format) Then
                If _wrong_format_value Is Nothing Or _wrong_format_value = "" Then
                    Return Format(val1, "dd/MM/yyyy")
                Else
                    Return _wrong_format_value
                End If
            Else
                Return Format(val1, _format)
            End If
        End Get
        Set(ByVal value As String)
            Me.IsEmptyValue = String.IsNullOrEmpty(value)
            If Me.IsEmptyValue Then Exit Property
            If String.IsNullOrEmpty(_format) Then
                If Not System.Text.RegularExpressions.Regex.IsMatch(value, RegExpDateFormats(_format_index)) Then
                    _wrong_format_value = value
                    val1 = Nothing
                    Throw New ArgumentException("Value has incorrect date format.")
                Else
                    _wrong_format_value = Nothing
                End If
                If Not DateTime.TryParseExact(value, DateFormats(_format_index), System.Globalization.CultureInfo.InvariantCulture, Globalization.DateTimeStyles.AssumeUniversal, val1) Then
                    _wrong_format_value = value
                    Throw New ArgumentException("Value has incorrect values for parts of the string that represent specific part of the date.")
                End If
            Else
                If Not DateTime.TryParseExact(value, _format, System.Globalization.CultureInfo.InvariantCulture, Globalization.DateTimeStyles.AssumeUniversal, val1) Then
                    _wrong_format_value = value
                    Throw New ArgumentException("Value has incorrect date format.")
                End If
            End If
        End Set
    End Property


    ' **************************************************************
    '         Convert line into array of dates
    ' **************************************************************
    Private Shared Function CDateArray(ByVal value As String, _
    ByVal format As String, Optional ByVal delimeter As String = "," _
      ) As Date()

        Dim dArr() As Date
        Dim v() As String
        Dim i As Integer

        v = Split(value, delimeter)
        ReDim dArr(0 To UBound(v))
        For i = 0 To UBound(dArr)
            If Not DateTime.TryParseExact(v(i), format, System.Globalization.CultureInfo.InvariantCulture, Globalization.DateTimeStyles.AssumeUniversal, dArr(i)) Then
                Throw New ArgumentException("Value is not a valid array of dates")
            End If
        Next i
        Return dArr

    End Function
    ' *********************************************************************************
    '                   Check if string is array of dates
    ' *********************************************************************************
    Public Shared Function ArrayOfDates(ByVal value As String, ByVal delimiter As String) As Boolean
        Dim v() As String

        v = Split(value, delimiter)
        Dim i As Integer
        For i = 0 To UBound(v)
            If Not IsDateFormat(v(i)) >= 0 Then
                Return False
            End If
        Next i
        Return True

    End Function



    ''' <summary>
    ''' Check if Strings are Equal
    ''' </summary>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Protected Overrides Function EvaluateEquals() As Boolean
        Return (val1 = val2)
    End Function

    ' ----------------------------------------------------------------------------
    '               CONDITION = NOT EQUALS
    ' ----------------------------------------------------------------------------
    ''' <summary>
    ''' Check if Numbers are not Equal
    ''' </summary>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Protected Overrides Function EvaluateNotEquals() As Boolean
        Return Not (val1 = val2)
    End Function

    Protected Overrides Function EvaluateBetween() As Boolean
        If UBound(val2_arr) = 1 Then ' Have 2 items only (array starts from Zero)
            Return val1 > val2_arr(0) AndAlso val1 < val2_arr(1)
        Else : Return False
        End If

    End Function

    ' ----------------------------------------------------------------------------
    '               CONDITION =  GREATER
    ' ----------------------------------------------------------------------------
    Protected Overrides Function EvaluateGreater() As Boolean
        Return (val1 > val2)
    End Function

    ' ----------------------------------------------------------------------------
    '               CONDITION =  GREATER OR EQUAL
    ' ----------------------------------------------------------------------------
    Protected Overrides Function EvaluateEqualGreater() As Boolean
        Return (val1 >= val2)
    End Function

    ' ----------------------------------------------------------------------------
    '               CONDITION =  LESS
    ' ----------------------------------------------------------------------------
    Protected Overrides Function EvaluateLess() As Boolean
        Return (val1 < val2)
    End Function

    ' ----------------------------------------------------------------------------
    '               CONDITION =  LESS OR EQUAL
    ' ----------------------------------------------------------------------------
    Protected Overrides Function EvaluateEqualLess() As Boolean
        Return (val1 <= val2)
    End Function

    ' ----------------------------------------------------------------------------
    '               CONDITION =  IN
    ' ----------------------------------------------------------------------------
    Protected Overrides Function EvaluateIN() As Boolean
        Dim k As Integer
        For k = 0 To val2_arr.Length - 1
            If val1 = val2_arr(k) Then Exit For
        Next
        Return (k <= val2_arr.Length - 1)
    End Function
    Protected Overrides Function EvaluateLike() As Boolean
        Return False
    End Function
    Protected Overrides Function EvaluateIsNull() As Boolean
        Return (_wrong_format_value Is Nothing OrElse _wrong_format_value = "")
    End Function
End Class