Utility 로 쓰면 어떨까 해서올립니다.
첫 소스는 codeproject 에서 가져왔는데요
조금 조금씩 수정했습니다.
코드보시면 이걸 왜 이렇게 했을까... 라는 생각을 갖게 하는 부분들이 있습니다. ㅋㅋ
필요하신 부분 있으시면 수정해서 사용하시면 좋을 듯합니다.
이런 코드도 있드라 정도로 생각해 두시면... ^^
이런식으로 자신만의 함수들을 따로 만들어 놓으시면
자신만의 프래임웍 유틸리티를 만들수 있겠죠? ^^
Imports System
Imports System.Reflection
Public Class Null
' define application encoded null values
Public Shared ReadOnly Property NullShort() As Short
Get
Return -1
End Get
End Property
Public Shared ReadOnly Property NullInteger() As Integer
Get
Return -1
End Get
End Property
Public Shared ReadOnly Property NullSingle() As Single
Get
Return Single.MinValue
End Get
End Property
Public Shared ReadOnly Property NullDouble() As Double
Get
Return Double.MinValue
End Get
End Property
Public Shared ReadOnly Property NullDecimal() As Decimal
Get
Return Decimal.MinValue
End Get
End Property
Public Shared ReadOnly Property NullDate() As Date
Get
Return Date.MinValue
End Get
End Property
Public Shared ReadOnly Property NullString() As String
Get
Return ""
End Get
End Property
Public Shared ReadOnly Property NullBoolean() As Boolean
Get
Return False
End Get
End Property
Public Shared ReadOnly Property NullGuid() As Guid
Get
Return Guid.Empty
End Get
End Property
' sets a field to an application encoded null value ( used in BLL layer )
Public Shared Function SetNull(ByVal objValue As Object, ByVal objField As Object) As Object
If IsDBNull(objValue) Then
If TypeOf objField Is Short Then
Return NullShort
ElseIf TypeOf objField Is Integer Then
Return NullInteger
ElseIf TypeOf objField Is Single Then
Return NullSingle
ElseIf TypeOf objField Is Double Then
Return NullDouble
ElseIf TypeOf objField Is Decimal Then
Return NullDecimal
ElseIf TypeOf objField Is Date Then
Return NullDate
ElseIf TypeOf objField Is String Then
Return NullString
ElseIf TypeOf objField Is Boolean Then
Return NullBoolean
ElseIf TypeOf objField Is Guid Then
Return NullGuid
Else ' complex object
Return Nothing
End If
Else ' return value
Return objValue
End If
End Function
' sets a field to an application encoded null value ( used in BLL layer )
Public Shared Function SetNull(ByVal objPropertyInfo As PropertyInfo) As Object
Select Case objPropertyInfo.PropertyType.ToString
Case "System.Int16"
Return NullShort
Case "System.Int32", "System.Int64"
Return NullInteger
Case "System.Single"
Return NullSingle
Case "System.Double"
Return NullDouble
Case "System.Decimal"
Return NullDecimal
Case "System.DateTime"
Return NullDate
Case "System.String", "System.Char"
Return NullString
Case "System.Boolean"
Return NullBoolean
Case "System.Guid"
Return NullGuid
Case Else
' Enumerations default to the first entry
Dim pType As Type = objPropertyInfo.PropertyType
If pType.BaseType.Equals(GetType(System.Enum)) Then
Dim objEnumValues As System.Array = System.Enum.GetValues(pType)
Array.Sort(objEnumValues)
Return System.Enum.ToObject(pType, objEnumValues.GetValue(0))
Else ' complex object
Return Nothing
End If
End Select
End Function
' convert an application encoded null value to a database null value ( used in DAL )
Public Shared Function GetNull(ByVal objField As Object, ByVal objDBNull As Object) As Object
GetNull = objField
If objField Is Nothing Then
Return objDBNull
ElseIf TypeOf objField Is Short Then
If Convert.ToInt16(objField) = NullShort Then
Return objDBNull
End If
ElseIf TypeOf objField Is Integer Then
If Convert.ToInt32(objField) = NullInteger Then
Return objDBNull
End If
ElseIf TypeOf objField Is Single Then
If Convert.ToSingle(objField) = NullSingle Then
Return objDBNull
End If
ElseIf TypeOf objField Is Double Then
If Convert.ToDouble(objField) = NullDouble Then
Return objDBNull
End If
ElseIf TypeOf objField Is Decimal Then
If Convert.ToDecimal(objField) = NullDecimal Then
Return objDBNull
End If
ElseIf TypeOf objField Is Date Then
' compare the Date part of the DateTime with the DatePart of the NullDate ( this avoids subtle time differences )
If Convert.ToDateTime(objField).Date = NullDate.Date Then
Return objDBNull
End If
ElseIf TypeOf objField Is String Then
If objField Is Nothing Then
Return objDBNull
Else
If objField.ToString = NullString Then
Return objDBNull
End If
End If
ElseIf TypeOf objField Is Boolean Then
If Convert.ToBoolean(objField) = NullBoolean Then
Return objDBNull
End If
ElseIf TypeOf objField Is Guid Then
If CType(objField, System.Guid).Equals(NullGuid) Then
Return objDBNull
End If
End If
End Function
' checks if a field contains an application encoded null value
Public Shared Function IsNull(ByVal objField As Object) As Boolean
If Not objField Is Nothing Then
If TypeOf objField Is Integer Then
Return objField.Equals(NullInteger)
ElseIf TypeOf objField Is Single Then
Return objField.Equals(NullSingle)
ElseIf TypeOf objField Is Double Then
Return objField.Equals(NullDouble)
ElseIf TypeOf objField Is Decimal Then
Return objField.Equals(NullDecimal)
ElseIf TypeOf objField Is Date Then
Dim objDate As DateTime = CType(objField, DateTime)
Return objDate.Date.Equals(NullDate.Date)
ElseIf TypeOf objField Is String Then
Return objField.Equals(NullString)
ElseIf TypeOf objField Is Boolean Then
Return objField.Equals(NullBoolean)
ElseIf TypeOf objField Is Guid Then
Return objField.Equals(NullGuid)
Else ' complex object
Return False
End If
Else
Return True
End If
End Function
End Class
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