I have a class that should do different things with a form.
Because these "things" are specific to the form, I store the reference to the form like this:
Friend Class clsEdit
Private m_Form As frmMain
And I pass it to the class like this:
Public Sub New(ByRef uForm As frmMain)
m_Form = uForm
End Sub
Now when my class should do these "things", I do it like this:
MyEditClass.DoThings()
Internally it looks like this:
Public Sub DoThis()
m_Form.SetHookPaused(True)
m_Form.StopCommonTimers()
End Sub
Protected Overrides Sub Finalize()
m_Form.DoSomethingThatOnlyThisFormCanDo()
End Sub
I would now like to be able to use clsEdit on a different form as well.
This other form also has the functions "DoThings" and "DoSomethingThatOnlyThisFormCanDo".
However, when I change the declaration of m_Form to this
Private m_Form As Form
... I can't do this anymore:
m_Form.DoThings()
... because "DoThings" is not a property / function of "Form".
And when I change it to this:
Private m_Form As frmOther
... I can't do that anymore:
Public Sub New(ByRef uForm As frmMain)
m_Form = uForm
End Sub
Can anybody tell me how I could do this?
Create your interface:
Public Interface IFormStuff
Sub SetHookPaused(value As Boolean)
Sub StopCommonTimers()
End Interface
Replace the form variable with the Interface variable in the class:
Public Class clsEdit
Private m_Form As IFormStuff
Public Sub New(f As IFormStuff)
m_Form = f
End Sub
Public Sub DoThis()
m_Form.SetHookPaused(True)
m_Form.StopCommonTimers()
End Sub
End Class
Implement the Interface in each form:
Public Class Form1
Implements IFormStuff
and each form needs to implement those interface stubs:
Public Sub SetHookPaused(value As Boolean) Implements IFormStuff.SetHookPaused
' do something
End Sub
Public Sub StopCommonTimers() Implements IFormStuff.StopCommonTimers
' do something
End Sub
then you need to create the class at the form level:
Private myEdit As clsEdit = Nothing
Protected Overrides Sub OnLoad(e As EventArgs)
MyBase.OnLoad(e)
myEdit = New clsEdit(Me)
End Sub
That's the gist of it.
Related
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
Need to call a sub that is coded written inside the block of form1 form an external worker thread. This is what I have written:
In Form1:
Public Delegate Sub UpdateControlDelegate(ByVal C As Label, ByVal txt As String)
Private Sub UpdateControl(ByVal C As Label, ByVal txt As String)
If C.InvokeRequired Then
C.Invoke(New UpdateControlDelegate(AddressOf UpdateControl), New Object() {C, txt})
Else
C.Text = txt
End If
End Sub
Public Sub DoStuff()
'we do some stuff then when it comnes time update a certain control:
Call UpdateControl(MyLabel, "My Text For The Label)
End Sub
In The workerThread that is located in a class:
Public Class MyClass
Public Sub UpdateData
Call Form1.DoStuff
End Sub
End Class
Does this look correct? The most simplest terms on what I am trying to achieve:
WorkerThread to call a Sub that is located in Class Form1
and that sub contains code that updates a couple controls in Form1.
After doing a little more research. I have figured it out. The initial code I have written is correct. The only thing missing is a reference to the form I need to update.
Here is the COMPLETE solution when needing to run a SUB from the UI that is called from the Worker Thread:
Public Class MyClass
'working thread is being within the subs of this class
Public MyForm1111 As Form1 '<------ The variable in this class that will reference to the form1 that we need
Public Sub MySubThatIsOnAWorkerThread
MyForm1111.DoStuff '<==== must call MyForm1111.DoStuff and NOT Form1.DoStuff
End Sub
End Class
The Sub Located In Form1:
Public Class Form1
Public Delegate Sub UpdateControlDelegate(ByVal C As Label, ByVal txt As String) 'Required Delegate
Private Sub UpdateControl(ByVal C As Label, ByVal txt As String) 'Sub to update controls
If C.InvokeRequired Then
C.Invoke(New UpdateControlDelegate(AddressOf UpdateControl), New Object() {C, txt})
Else
C.Text = txt
End If
End Sub
Public Sub DoStuff() 'the sub we need to call from the worker thread
'do some calculations and code
Call UpdateControl(MyLabel, "Some Text For Label")
End Sub
Private Sub Form1_Load()
MyClass.MyForm1111 = Me <==== Set the reference here in your Form1_Load
End Sub
End Class
is there a way to access a variable in Form_Load from an event handler?
Please dont mind the code, this is just a representation of my question.
Public Class Form
Public Sub Form_Load()
Dim x as string
x = MyClass.MethodGetValue()
End Sub
Private Shared Sub OnChanged()
MyClass2.MethodGetValue(x)
End Sub
End Class
It's about the scope of the variable. In your situation you need a class variable. This allows it to be used anywhere inside of this class.
Public Class Form1
Private x As Object 'pick the datatype that matches your needs
Public Sub Form_Load()
x = MyClass.MethodGetValue()
End Sub
Private Sub OnChanged()
MyClass2.MethodGetValue(x)
End Sub
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