在 VB.net 中使用类

Question

Excuse me if i sound like a complete noob or use improper terminology below.

I am trying to create a class in vb.net from which multiple form class can inherit from. So in the 'form class' if i say, get a list from the user, sent it to the 'seperate class' to order the list and then pass the list back to the form class to save in a database or do whatever with how would i proceed.

So far this is what i have done.

below is the class itself without the contents

Public Class RandomClassName

End Class

Below is what i have done to 'inherit' from the above class

Public Class frmStudentLogin
Dim con As New OleDbConnection
Dim ValidUserNameLength As Boolean
Inherits RandomClassName

I would like to know how i would set up the code to allow me to properly inherit from and refer to the class link.

Thanks.

Answer 1

It is not clear which problem are you trying to solve with this inheritance approach, but surely you could inherit a form class (MyForm) from another class (BaseForm) provided that the other class (BaseForm) inherits from the form base class (Form).

At that point you could insert in the MyForm all the function that you want to share between your forms but be aware that, in this scenario, every form will be affected by your BaseForm class

I will show an example tested in LinqPAD

Sub Main

    Dim x = New MyForm()
    x.Show()

End Sub

Public Class MyForm
    Inherits BaseForm

    Public Sub New ()
        Dim txt = New TextBox()
        txt.Multiline = True
        txt.Height = 200

        'Here you could use the GetAList from the BaseForm class
        ' and use it to set the initial text for the multiline textbox.
        txt.AppendText (String.Join(Environment.NewLine, GetAList().ToArray()))
        Me.Controls.Add(txt)
    End Sub
End Class


Public Class BaseForm
    Inherits Form

    ' Common methods required by your uplevel forms
    Public Function GetAList() As List(Of String)
        Dim a = New List(Of String)() From
            {"ABC", "DEF", "GHJ"}
        Return a
    End Function

End Class