Why this code is going wrong

[Deepak Sakpal]

Hi, paste this code in Form1

This is the code:

Public Delegate Function MessageBoxShowHandler(ByVal test As String) As DialogResult
    Dim del As New MessageBoxShowHandler(AddressOf MessageBox.Show)
 
    Dim WithEvents clsOuterClass As OuterClass
 
    Public Class OuterClass
        Public OuterOutput0 As Short
        Public Event ThrdCmplt0(ByVal OuterOutput0 As Short)
 
        Dim WithEvents clsInnerClass As InnnerClass
 
        Public Sub OuterProcedure()
            clsInnerClass = New InnnerClass()
            Dim Thread0 As New System.Threading.Thread(AddressOf clsInnerClass.InnerProcedure0)
            clsInnerClass.InnerInput0 = 10000
            Thread0.Start()
        End Sub
 
        Sub InnerProcedure0_EventHandler(ByVal InnerOutput0 As Short) Handles clsInnerClass.ThreadComplete0
            OuterOutput0 = InnerOutput0
            RaiseEvent ThrdCmplt0(OuterOutput0)
        End Sub
    End Class
 
    Public Sub Outer_EventHandler(ByVal OuterOutput0 As Short) Handles clsOuterClass.ThrdCmplt0
        del.BeginInvoke(CStr(OuterOutput0), Nothing, Nothing)
    End Sub
 
    Public Class InnnerClass
        Public InnerInput0 As Short
        Public InnerOutput0 As Short
 
        Public Event ThreadComplete0(ByVal InnerOutput0 As Short)
 
        Public Sub InnerProcedure0()
            Dim iCtr0 As Short
            For iCtr0 = 1 To InnerInput0
                InnerOutput0 = InnerOutput0 + 1
            Next
            RaiseEvent ThreadComplete0(InnerOutput0)
        End Sub
    End Class
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim i As Short
        '
        '-->> Why this code don't displays messagebox 5 times <<--
        For i = 1 To 5
            clsOuterClass = New OuterClass()
            Dim Thrd0 As New System.Threading.Thread(AddressOf clsOuterClass.OuterProcedure)
            Thrd0.Start()
        Next
        '^^^^^^^^^^^^^^^^^^^^^^^
    End Sub

Please help me

[Memnoch1207]

Change this

Public Sub Outer_EventHandler(ByVal OuterOutput0 As Short) Handles clsOuterClass.ThrdCmplt0
        del.BeginInvoke(CStr(OuterOutput0), Nothing, Nothing)
    End Sub

To this

Public Sub Outer_EventHandler(ByVal OuterOutput0 As Short) Handles clsOuterClass.ThrdCmplt0
     Dim i As Short
 
     For i = 1 To 5
         del.BeginInvoke(CStr(OuterOutput0), Nothing, Nothing)
     Next
End Sub

[Deepak Sakpal]

Thanks for replying.

Public Sub Outer_EventHandler(ByVal OuterOutput0 As Short) Handles clsOuterClass.ThrdCmplt0
     Dim i As Short
 
     For i = 1 To 5
         del.BeginInvoke(CStr(OuterOutput0), Nothing, Nothing)
     Next
End Sub

Above code just displays same output 5 times. What my requirement is, value of OuterOutput0 may differ in each instance of clsOuterClass, so i am using the code below

Dim i As Short
'
'-->> Why this code don't displays messagebox 5 times <<--
For i = 1 To 5
    clsOuterClass = New OuterClass()
    Dim Thrd0 As New System.Threading.Thread(AddressOf clsOuterClass.OuterProcedure)
    Thrd0.Start()
Next
'^^^^^^^^^^^^^^^^^^^^^^^

[Edneeis]

It only shows one because the first line in the loop:
clsOuterClass = New OuterClass
Writes over the previous instance of clsOuterClass before it has raised the event. Also the samething happens in the OuterClass in the OuterProcedure method. The first line resets the inner instance of InnerClass before the even is raised. I'm not sure what real world example this relates to but that is a lot of wicked threading. Try this:

Public Delegate Function MessageBoxShowHandler(ByVal test As String) As DialogResult
    Dim del As New MessageBoxShowHandler(AddressOf MessageBox.Show)
 
    Dim WithEvents clsOuterClass As New OuterClass 'intialize with class
 
    Public Sub Outer_EventHandler(ByVal OuterOutput0 As Short) Handles clsOuterClass.ThrdCmplt0
        del.BeginInvoke(CStr(OuterOutput0), Nothing, Nothing)
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim i As Short
        '
        '-->> Why this code don't displays messagebox 5 times <<--
        For i = 1 To 5
            'clsOuterClass = New OuterClass
            Dim Thrd0 As New System.Threading.Thread(AddressOf clsOuterClass.OuterProcedure)
            Thrd0.Start()
        Next
        '^^^^^^^^^^^^^^^^^^^^^^^
    End Sub
 
Public Class InnnerClass
    Public InnerInput0 As Short
    Public InnerOutput0 As Short
 
    Public Event ThreadComplete0(ByVal InnerOutput0 As Short)
 
    Public Sub InnerProcedure0()
        Dim iCtr0 As Short
        For iCtr0 = 1 To InnerInput0
            InnerOutput0 = InnerOutput0 + 1
        Next
        RaiseEvent ThreadComplete0(InnerOutput0)
    End Sub
End Class
 
Public Class OuterClass
    Public OuterOutput0 As Short
    Public Event ThrdCmplt0(ByVal OuterOutput0 As Short)
 
    Dim WithEvents clsInnerClass As New InnnerClass 'intialize with class
 
    Public Sub OuterProcedure()
        'clsInnerClass = New InnnerClass
        Dim Thread0 As New System.Threading.Thread(AddressOf clsInnerClass.InnerProcedure0)
        clsInnerClass.InnerInput0 = 1000 'I took a zero out to fit within the limits of short
        Thread0.Start()
    End Sub
 
    Sub InnerProcedure0_EventHandler(ByVal InnerOutput0 As Short) Handles clsInnerClass.ThreadComplete0
        OuterOutput0 = InnerOutput0
        RaiseEvent ThrdCmplt0(OuterOutput0)
    End Sub
End Class