Visual Basic

Member 15078716 wrote:

Who else has noticed this capacity?

Member 15078716 wrote:

Does the latest version of Visual Studio have this capacity for it's listbox?

Quote:

Does the latest version of Visual Studio have this capacity for it's listbox?

Victor Nijegorodov wrote:

... abd does it work?

jsc42 wrote:

why is the value to be subtracted converted to a String and then parsed to CInt only for it to be boxed (a Javaism) / wrappered (JSism) back to a String?

Public Class Form1
    Public Event Show_My_Message(ByVal message As String)

    Private Sub btnOpenForm2_Click(sender As Object, e As EventArgs) Handles btnOpenForm2.Click
        Dim form2 As New Form2(Me)         ' This passes the reference to the Form1 instance to the Form2 instance
        form2.Show()                       ' Show an instance of Form2
    End Sub

    Private Sub btnShowMessageOnForm2_Click(sender As Object, e As EventArgs) Handles btnShowMessageOnForm2.Click
        RaiseEvent Show_My_Message("Some message")
    End Sub
End Class

Public Class Form2
    Public Sub New(Form1 eventProvider)       ' THIS IS BAD PRACTICE! Form1 should be replaced by an interface!
        AddHandler eventProvider.Show_My_Message, AddressOf ShowMyMessageHandler
    End Sub

    Public Sub ShowMyMessageHandler(ByVal message As String)
        MsgBox(message)
    End Sub
End Class

Public Class Form1
    Private f2 As Form2 = Nothing

    Sub F2IsActive(Enabled As Boolean)
        btnStartForm2.Enabled = Not Enabled
        btnDoSomethingOnForm2.Enabled = Enabled
        btnCloseForm2.Enabled = Enabled

        If Enabled Then
            If Not FormIsOpen(f2) Then  ' Needs to be opened
                f2 = New Form2()
                f2.Show()
            End If
        ElseIf FormIsOpen(f2) Then   ' Needs to be closed
            f2.Close()
            f2 = Nothing
        End If
    End Sub

    Private Sub btnStartForm2_Click(sender As Object, e As EventArgs) Handles btnStartForm2.Click
        F2IsActive(True)
    End Sub

    Private Sub btnDoSomethingOnForm2_Click(sender As Object, e As EventArgs) Handles btnDoSomethingOnForm2.Click
        If f2 Is Nothing Then
            MsgBox("You have to open Form2 first")
        ElseIf FormIsOpen(f2) Then
            f2.DoSomethingOnForm2()
        Else    ' No longer exists
            MsgBox("Form2 has disappeared")
            F2IsActive(False)
        End If
    End Sub

    Private Function FormIsOpen(formToFind As Form) As Boolean
        For Each testform As Form In Application.OpenForms
            If testform.Equals(formToFind) Then
                Return True
            End If
        Next

        Return False
    End Function

    Private Sub btnCloseForm2_Click(sender As Object, e As EventArgs) Handles btnCloseForm2.Click
        If Not FormIsOpen(f2) Then
            MsgBox("Form2 has already been closed")
        End If

        F2IsActive(False)
    End Sub

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        F2IsActive(False)
    End Sub
End Class

Public Class Form2
    Public Sub DoSomethingOnForm2()
        MsgBox("Hello from Form 1")
    End Sub
End Class