I want to call Dim objFkkiNinteiJokyoRpt As New A(objCsv) in class C. But class A Inherits Common. If now call contructor will An error occurred.Because type Object C.CsvGenerator diference type Object in common. I thnk now stop call to contructor common (or any other way) but i dont know how to do. Helf me please. Sorry because my english so bad
Public Class A Inherits Common
Public _objCsv As C.CsvGenerator
Friend Sub New(ByVal objCsv As C.CsvGenerator)
_objCsv = objCsvGenerator
End Sub
Public Sub New()
End Sub
End Sub
Public Sub New(ByVal objRSReportObj As Object)
MyBase.New(objRSReportObj)
InitializeReport()
End Sub
End Class
Public Class C
Private Function SelectCSV
Dim objCsv As New CsvGenerator("")
Dim objFkkiNinteiJokyoRpt As New A(objCsv)
End Function
Friend Class CsvGenerator
Inherits cmShare.cmObject
End Class
End Class
Public Class Common
Public Sub New()
MyBase.New()
End Sub
Public Sub New(ByVal objRSReport As Object)
MyBase.New(objRSReport)
End Sub
End Class
Related
I'm trying to centralize all formatting and conversion rule in a single class especific. Using the interface INotifyRead(Of T As Class). When I implement the methods BeforeRead/AfterRead throws an exception: Unable to cast object of type 'Especific' to type 'FileHelpers.Events.INotifyRead`1[System.Object]'.
Below my code.
Using engine As New MultiRecordEngine(New RecordTypeSelector(AddressOf CifraRecordTypeSelector),
GetType(RemessaRegistroCliente),
GetType(RemessaRegistroContrato))
Dim records = engine.ReadFile(_camArquivo)
End Using
Public NotInheritable Class RemessaRegistroCliente
Implements INotifyRead(Of RemessaRegistroCliente)
Public Sub AfterRead(e As AfterReadEventArgs(Of RemessaRegistroCliente)) Implements INotifyRead(Of RemessaRegistroCliente).AfterRead
End Sub
Public Sub BeforeRead(e As BeforeReadEventArgs(Of RemessaRegistroCliente)) Implements INotifyRead(Of RemessaRegistroCliente).BeforeRead
End Sub
End Class
Public NotInheritable Class RemessaRegistroContrato
Implements INotifyRead(Of RemessaRegistroContrato)
Public Sub AfterRead(e As AfterReadEventArgs(Of RemessaRegistroContrato)) Implements INotifyRead(Of RemessaRegistroContrato).AfterRead
End Sub
Public Sub BeforeRead(e As BeforeReadEventArgs(Of RemessaRegistroContrato)) Implements INotifyRead(Of RemessaRegistroContrato).BeforeRead
End Sub
End Class
Since MultiRecordEngine has no generic version, you cannot implement the generic INotifyRead(Of T) to handle events. Instead, assign delegates to the engine.
Sub Main()
Using engine As New MultiRecordEngine(New RecordTypeSelector(AddressOf CifraRecordTypeSelector),
GetType(RemessaRegistroCliente),
GetType(RemessaRegistroContrato))
AddHandler engine.BeforeReadRecord, AddressOf BeforeReadRecordHandler
End Using
End Sub
Private Sub BeforeReadRecordHandler(ByVal engine As EngineBase, ByVal e As BeforeReadEventArgs(Of Object))
End Sub
You'll also need to modify your classes to remove the generic interfaces:
Public NotInheritable Class RemessaRegistroCliente
'your fields
End Class
Public NotInheritable Class RemessaRegistroContrato
'your fields
End Class
Public Class Class1
Private names As List(Of String)
Private _class2 As New Class2
Public Sub AddName(ByVal name As String)
names.Add(name)
_class2.Add()
End Sub
Public ReadOnly Property AddAge(ByVal name As String) As Class2
Get
_class2.index = names.IndexOf(name)
Return _class2
End Get
End Property
Public Sub Clear()
names.Clear()
_class2.Clear()
End Sub
Public Class Class2
Private _age As List(Of Integer)
Protected Friend index As Integer
Public Property Age() As Integer
Get
Return _age(index)
End Get
Set(ByVal value As Integer)
_age(index) = value
End Set
End Property
Public Sub Add()
_age.Add(0)
End Sub
Public Sub Clear()
_age.Clear()
End Sub
End Class
End Class
How can I hide ,Sub Clear and Sub Add on class2, so they'll only be visible on class1, like;
Public Sub Clear()
names.Clear()
_class2.Clear() '<<<<<<<
End Sub
I want they do not be visible on Sub Main(), like they are below.
Sub Main()
Dim person As New Class1
person.AddAge("kid").Clear() '<<<<<<
person.AddAge("kid").Add() '<<<<<<
End Sub
If I put Protected, I class1 cannot access it. If I put Protected Friend, Sub Main() can still access them. Thanks for your help and time.
Used -Hans Passant- comment.
"Trust in .NET follows assembly boundaries. If you get two classes in one assembly then there are two programmers that know how to find each other if there's a problem. The only way to get what you want is to put these classes in a separate class library project. Which then lets you use Friend. And whomever writes that Main method doesn't have to be friendly."
Say I have a class with several methods within it. I want to organize the methods into groupings that can be accessed without constructing a new object each time. The purpose is to group the methods of the class into logical buckets
For instance:
Dim myclass as MyCustomClass
myclass.Shipping.Get_List()
myclass.Production.Get_List()
What is the best way to do this? I tried nested classes, but VB.NET won't let me access the methods as shown above.
so this is how i would do what you want
this is not the best design of the world but it would work
I would suggest you to move the actual get_list and other kind of method / property into the specific class while keeping the common one in the parent class, which in this case is test
but then, I have no idea what your code look like so from that point on, it's your choice
Module Module1
Sub Main()
Dim test As New test
test.Production.Get_List()
test.Shipping.Get_List()
End Sub
End Module
Public Class Shipping
Private parent As test
Public Sub New(ByRef parent As test)
Me.parent = parent
End Sub
Public Function Get_List() As List(Of Integer)
Return parent.GetShipping_List
End Function
End Class
Public Class Production
Private parent As test
Public Sub New(ByRef parent As test)
Me.parent = parent
End Sub
Public Function Get_List() As List(Of Integer)
Return parent.GetProduction_List
End Function
End Class
Public Class test
Public Property Production As Production
Public Property Shipping As Shipping
Public Function GetShipping_List() As List(Of Integer)
Return Nothing
End Function
Public Function GetProduction_List() As List(Of Integer)
Return Nothing
End Function
Public Sub New()
Production = New Production(Me)
Shipping = New Shipping(Me)
End Sub
End Class
With caution that you more than likely should re-evaluate your architecture, you could implement your pattern like this:
Public Class MyCustomClass
Private _shippingList As List(Of String)
Private _productionList As List(Of String)
Public Production As ProductionClass
Public Shipping As ShippingClass
Public Sub New()
Production = New ProductionClass(Me)
Shipping = New ShippingClass(Me)
End Sub
Public Class ShippingClass
Private _owner As MyCustomClass
Public Sub New(owner As MyCustomClass)
_owner = owner
End Sub
Public Function Get_List()
Return _owner._productionList
End Function
End Class
Public Class ProductionClass
Private _owner As MyCustomClass
Public Sub New(owner As MyCustomClass)
_owner = owner
End Sub
Public Function Get_List()
Return _owner._productionList
End Function
End Class
End Class
However, if your true intent is simply organizing the methods in a more accessible and logical manner, I would suggest considering:
Public Class MyCustomClass
Public Sub ShippingListGet()
End Sub
Public Sub ShippingListAddTo()
End Sub
Public Sub ShippingThatDO()
End Sub
Public Sub ShippingThisDo()
End Sub
Public Sub ProductionListGet()
End Sub
Public Sub ProductionListAddTo()
End Sub
Public Sub ProductionThisDo()
End Sub
Public Sub ProductionThatDo()
End Sub
End Class
Keep in mind, some people consider that difficult to read. I personally prefer organization along those lines so when the methods are sorted alphabetically they group logically.
I have found the solution I was looking for using interfaces
Public Interface ICompany
Function Company_List() As DataTable
End Interface
Public Class MainClass
Public Company As ICompany = New CompanyClass
Public Sub New()
MyBase.New()
End Sub
Private Class CompanyClass
Public Sub New()
MyBase.New()
End Sub
Public Function Company_List() As DataTable
My code....
End Function
End Class
End Class
I have these two classes class FootballAdmin makes use of the import Football from the projects references, what i need to do is in class MainForm is for the updateView method to access the list held by FootballAdmin and display it in the teamSheetListBox, i am unsure how access the list as indicated by ?????
Imports Football
Public Class FootballAdmin
Private fTeam As List(Of FootballTeams)
Public Sub New()
fTeam = New List(Of FootballTeams)
End Sub
Public ReadOnly Property Teams() As List(Of FootballTeams)
Get
Return fTeams
End Get
End Property
End Class
Public Class MainForm
Private fFootballAdmin As FootballAdmin
Public Sub New()
InitializeComponent()
fFootballAdmin = New FootballAdmin
updateView()
End Sub
Private sub updateView()
For each team As String In ????????
teamSheetListBox.Items.Add(team)
Next
End Sub
End Class
Help please!
The big hint I am going to give you is that team in your loop:
For each team As String In ????????
teamSheetListBox.Items.Add(team)
Next
Isn't going to be a String. It will be the same type: FootballTeam as in your FootballAdmin Class. Consider what you have access to in your MainForm that can get you to those types.
Is there a way to have a class collection of inherited types be initialized?
For example, here is my code:
Public Class CamryCar
Property Name As String = "Camry"
Property Color As String
End Class
Public Class RedCamry
Inherits CamryCar
Sub New()
MyBase.New()
Color = "Red"
End Sub
End Class
Public Class BlueCamry
Inherits CamryCar
Sub New()
MyBase.New()
Color = "Blue"
End Sub
End Class
What I'm doing today for a colllection is:
Public Class Camrys
Property Cars As New List(Of CamryCar) From {New RedCamry, New BlueCamry}
End Class
But this gives me an extra property of Cars.
I can also do this:
Public Class Camrys
Inherits List(Of CamryCar)
End Class
I prefer this one as I don't have an extra property to deal with. But I can find a way to initialize that that list with objects of RedCamry and BlueCamry.
Is it impossible or is there another way to do this?
Just another option. I'd probably pass the list in to the constructor. I also added an additional Sub New() that will initialize the collection via reflection.
Imports System.Reflection
Module Module1
Sub Main()
Dim camrys As New Camrys
For Each camry As CamryCar In camrys
Console.WriteLine(camry.Color)
Next
Console.ReadKey()
End Sub
End Module
Public Class Car
End Class
Public Class CamryCar
Inherits Car
Property Name As String = "Camry"
Property Color As String
End Class
Public Class RedCamry
Inherits CamryCar
Sub New()
MyBase.New()
Color = "Red"
End Sub
End Class
Public Class BlueCamry
Inherits CamryCar
Sub New()
MyBase.New()
Color = "Blue"
End Sub
End Class
Public Class Camrys
Inherits List(Of CamryCar)
Public Sub New(ByVal Camrys As List(Of CamryCar))
MyBase.New()
For Each Camry As CamryCar In Camrys
Add(Camry)
Next
End Sub
Public Sub New()
MyBase.New()
InitializeCamrys()
End Sub
Public Sub InitializeCamrys()
Dim asm As Assembly = Assembly.GetExecutingAssembly()
For Each t As Type In asm.GetTypes()
If GetType(CamryCar) Is t.BaseType Then
Dim camry As CamryCar = Activator.CreateInstance(t)
Add(camry)
End If
Next
End Sub
End Class
It seems like you're looking for a factory style function.
Module Factory
Public Function CreateCamrysList As List(of CamryCar)
Return New List(Of CamryCar) From {New RedCamry, New BlueCamry}
End Function
End Module
Now you can use the function CreateCamrysList wherever you need the list of CamryCar objects.
Note: Deriving from List(Of T) is in general a bad solution. If you do need to derive it's better to choose Collection(Of T).
You need to initialize it in a constructor:
Public Class Camrys
Inherits List(Of CamryCar)
Public Sub New()
MyBase.New()
Add(New RedCamry())
Add(New BlueCamry())
End Sub
End Class