FIX: A gradual memory leak occurs in a WinForm application when you create, modify, or remove a MenuItem property for an MDI form in the .NET Framework 1.1 (873429)

MORE INFORMATION

Steps to reproduce the problem

1. Create a Visual Basic .NET MDI Form by using the following code.

   Private Sub frmStart_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
   Menu = MenuMainSetup()
   
   End Sub
   
   
   Public Function MenuMainSetup() As MainMenu
   ' Set up main menu with 1 item (Member) and two subitems (Open and Close Member)
   
   
   Dim mnuMain As New MainMenu
   
   
   Dim mitAdd As New MenuItem("Member")
   
   mitAdd.MergeType = MenuMerge.MergeItems
   
   mitAdd.MergeOrder = 1
   
   Dim i As Integer = mnuMain.MenuItems.Add(mitAdd)
   
   
   
   mitAdd = New MenuItem("Open", New EventHandler(AddressOf zOpenChild))
   
   mitAdd.MergeType = MenuMerge.MergeItems
   mitAdd.MergeOrder = 1
   
   mnuMain.MenuItems(i).MenuItems.Add(mitAdd)
   
   mitAdd = New MenuItem("Close Member")
   
   mitAdd.MergeType = MenuMerge.MergeItems
   
   mitAdd.Visible = False
   
   mitAdd.MergeOrder = 2
   
   mnuMain.MenuItems(i).MenuItems.Add(mitAdd)
   
   
   mitAdd = New MenuItem("Test GC", New EventHandler(AddressOf Test))
   
   mitAdd.MergeType = MenuMerge.MergeItems
   
   mitAdd.MergeOrder = 3
   
   mnuMain.MenuItems(i).MenuItems.Add(mitAdd)
   
   
   
   Return mnuMain
   
   End Function
   
   
   Public Function MenuSubSetup() As MainMenu
   
   ' Set up additional History menu item to go in Member menu
   
   Dim mnuMain As New MainMenu
   
   Dim mitAdd As New MenuItem("Member")
   
   mitAdd.MergeType = MenuMerge.MergeItems
   
   mitAdd.MergeOrder = 1
   
   Dim i As Integer = mnuMain.MenuItems.Add(mitAdd)
   
   
   
   mitAdd = New MenuItem("History")
   
   mitAdd.MergeType = MenuMerge.MergeItems
   
   mitAdd.MergeOrder = 4
   
   mnuMain.MenuItems(i).MenuItems.Add(mitAdd)
   
   mitAdd = Nothing
   
   Return mnuMain
   
   End Function
   
   
   Private Sub zOpenChild(ByVal sender As System.Object, ByVal e As System.EventArgs)
   
   ' Open our only child
   
   Dim f As New frmMemLeak
   
   
   f.MdiParent = Me
   
   f.Show()
   
   End Sub
   
   
   Private Sub Test(ByVal sender As System.Object, ByVal e As System.EventArgs)
   GC.Collect()
   
   GC.WaitForPendingFinalizers()
   
   End Sub

2. Create a Windows Form by using the following code.

   Region " Windows Form Designer generated code "
   
   
   Public Class frmMemLeak : Inherits System.Windows.Forms.Form
   
   
   
   #Region " Windows Form Designer generated code "
   
   
   
   Public Sub New()
   
   MyBase.New()
   
   
   
   'This call is required by the Windows Form Designer.
   
   InitializeComponent()
   
   
   
   'Add any initialization after the InitializeComponent() call
   
   
   End Sub
   
   'Form overrides dispose to clean up the component list.
   
   Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
   
   If disposing Then
   
   If Not (components Is Nothing) Then
   
   components.Dispose()
   
   End If
   End If
   
   MyBase.Dispose(disposing)
   
   End Sub
   
   'Required by the Windows Form Designer
   
   Private components As System.ComponentModel.IContainer
   
   
   
   'NOTE: The following procedure is required by the Windows Form Designer
   
   'It can be modified using the Windows Form Designer. 
   
   'Do not modify it using the code editor.
   
   Private WithEvents cmdClose As System.Windows.Forms.Button
   
   <System.Diagnostics.DebuggerStepThrough()> 
   
   Private Sub InitializeComponent()
   
   Me.cmdClose = New System.Windows.Forms.Button
   
   Me.SuspendLayout()
   
   '
   
   'cmdClose
   
   '
   Me.cmdClose.Location = New System.Drawing.Point(16, 16)
   
   Me.cmdClose.Name = "cmdClose"
   
   Me.cmdClose.TabIndex = 5
   
   Me.cmdClose.Text = "Close"
   
   '
   
   'frmMemLeak
   
   '
   
   Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
   
   Me.ClientSize = New System.Drawing.Size(104, 61)
   
   Me.Controls.Add(Me.cmdClose)
   
   Me.Name = "frmMemLeak"
   
   Me.Text = "Leak"
   
   Me.ResumeLayout(False)
   
   End Sub
   
   
   
   #End Region
   
   
   Private Sub frmMemLeak_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
   
   ' Disable the Close Member menu item
   
   
   MdiParent.Menu.MenuItems(0).MenuItems(1).Enabled = False
   
   
   End Sub
   
   
   
   Private Sub frmMemLeak_Activated(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Activated
   
   ' Add the History menu item to the Member menu
   
   Menu = CType(MdiParent, frmStart).MenuSubSetup
   
   
   
   End Sub
   
   
   
   Private Sub cmdClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdClose.Click
   
   
   MdiParent.Menu.MenuItems(0).MenuItems(1).Enabled = True
   
   
   Me.Close()
   
   
   End Sub
   
   End Class

3. Run the application.
4. In the application, click Member, and then click Open.
5. In the application, click Member, and then click Test GC.
6. Repeat steps 4 and 5 several times to create the leak.