Raise Event on another Form-CodePudding

subject is declare event on Form1 , and run that event on Form2 here is the code , but event doesnt work on Form2 !! what is missing here?? many thanks

Form1:

Public Class Form1

    Private Sub btnOpenForm2_Click(sender As Object, e As EventArgs) Handles btnOpenForm2.Click
        Form2.Show()
    End Sub

    Public Event show_My_Message()
    Private Sub btnShowMessageOnForm2_Click(sender As Object, e As EventArgs) Handles btnShowMessageOnForm2.Click
        RaiseEvent show_My_Message()
    End Sub

End Class

Form2:

Public Class Form2

    Public WithEvents My_Form1 As Form1 = New Form1
    Private Sub Show_My_Message_On_Form2() Handles My_Form1.show_My_Message
        MsgBox("Hello")
    End Sub

End Class

CodePudding user response：

Here's an example of what Jimi was talking about, using the .Owner property.

Form1:

Public Class Form1

    Private Sub btnOpenForm2_Click(sender As Object, e As EventArgs) Handles btnOpenForm2.Click
        Form2.Show(Me) ' <-- Pass Form1 into Form2 via Show()
    End Sub

    Public Event show_My_Message()
    Private Sub btnShowMessageOnForm2_Click(sender As Object, e As EventArgs) Handles btnShowMessageOnForm2.Click
        RaiseEvent show_My_Message()
    End Sub

End Class

Form2:

Public Class Form2

    Private WithEvents My_Form1 As Form1

    Private Sub Form2_Shown(sender As Object, e As EventArgs) Handles Me.Shown
        If Not IsNothing(Me.Owner) AndAlso Me.Owner Is Form1 Then
            My_Form1 = DirectCast(Me.Owner, Form1)
        End If
    End Sub

    Private Sub F1_show_My_Message() Handles My_Form1.show_My_Message
        MessageBox.Show("Hello")
    End Sub

End Class

CodePudding user response：

Try it without cross form event handling,

Form1

Public MyForm2 As Form2
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    If MyForm2 Is Nothing Then
        MyForm2 = New Form2
    End If
    MyForm2.Show()
    MyForm2.Show_My_Message_On_Form2("Hello")
End Sub

Form2

Public Class Form2

    Public Sub Show_My_Message_On_Form2(theMess As String)
        MessageBox.Show(theMess)
    End Sub

End Class