FIX: You cannot scroll down an MDI child form by clicking the scroll-down arrow

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SYMPTOMS
When a user control is present on a Multiple Document Interface (MDI) child form, you cannot scroll down. This problem occurs when the user control contains the focus. You try to scroll down by using the scroll-down arrow on the scroll bar of the child form, but you cannot scroll down.
CAUSE
When a user control contains the focus, the user control is an active control. However, when the user control contains the focus, the ActiveControl.Focused property that is present in the Microsoft .NET Framework 1.1 returns False instead of returning True. Therefore, focusing the user control forces the form to make the user control visible. This problem occurs when you perform a scroll-down operation by clicking the scroll-down arrow.
RESOLUTION
To resolve this problem, obtain the latest service pack for the Microsoft .NET Framework 1.1. The following file is available for download from the Microsoft Download Center:

The Microsoft .NET Framework 1.1 Service Pack 1
STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in the Microsoft .NET Framework 1.1 Service Pack 1.
MORE INFORMATION

Steps to reproduce the problem

  1. Create a user control file. To do this, follow these steps:
    1. Start Microsoft Visual Studio .NET.
    2. On the File menu, point to New, and then click Project.

      The New Project dialog box appears.
    3. Under Project Types, click Visual Basic Projects.
    4. Under Templates, click Windows Control Library.
    5. In the Name box, type testusercontrol, and then click OK.

      By default, the file that is named Usercontrol1.vb appears.
    6. Add a TextBox control to the Usercontrol1.vb [Design] file.
    7. On the Build menu, click Build Solution.
  2. Add a Windows application to the project. To do this, follow these steps:
    1. On the File menu, point to Add Project, and then click New Project.

      The New Project dialog box appears.
    2. Under Project Types, click Visual Basic Projects.
    3. Under Templates, click Windows Application.
    4. In the Name box, type user_control_scroll_UI, and then click OK.

      By default, the form that is named Form1 appears.
    5. In Solution Explorer, right-click user_control_scroll_UI, and then click Add Reference.

      The Add Reference dialog box appears.
    6. Click the Projects tab, click Select, and then click OK to add the testusercontrol to your project reference.
    7. Right-click the form that is named Form1, and then click View Code.
    8. Replace the existing code with the following code:
      Option Strict OnOption Explicit On Public Class MDIChild    Inherits System.Windows.Forms.Form#Region " Windows Forms Designer generated code "    Public Sub New()        MyBase.New()        'This call is required by the Windows Forms Designer.        InitializeComponent()        'Add any initialization after the InitializeComponent() call.    End Sub    'The 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    'This is required by the Windows Forms Designer.    Private components As System.ComponentModel.IContainer    'Note The following procedure is required by the Windows Forms Designer.    'The following procedure can be modified by using the Windows Forms Designer.      'Do not modify the following procedure by using the code editor.    Friend WithEvents UserControl11 As testusercontrol.UserControl1    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox    Friend WithEvents TextBox3 As System.Windows.Forms.TextBox    Friend WithEvents TextBox4 As System.Windows.Forms.TextBox    Friend WithEvents TextBox5 As System.Windows.Forms.TextBox    Friend WithEvents TextBox6 As System.Windows.Forms.TextBox    Friend WithEvents UserControl12 As testusercontrol.UserControl1    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()        Me.UserControl11 = New testusercontrol.UserControl1        Me.TextBox1 = New System.Windows.Forms.TextBox        Me.TextBox2 = New System.Windows.Forms.TextBox        Me.TextBox3 = New System.Windows.Forms.TextBox        Me.TextBox4 = New System.Windows.Forms.TextBox        Me.TextBox5 = New System.Windows.Forms.TextBox        Me.TextBox6 = New System.Windows.Forms.TextBox        Me.UserControl12 = New testusercontrol.UserControl1        Me.SuspendLayout()        '        'UserControl11        '        Me.UserControl11.Location = New System.Drawing.Point(26, 30)        Me.UserControl11.Name = "UserControl11"        Me.UserControl11.Size = New System.Drawing.Size(104, 24)        Me.UserControl11.TabIndex = 0        '        'TextBox1        '        Me.TextBox1.Location = New System.Drawing.Point(26, 161)        Me.TextBox1.Name = "TextBox1"        Me.TextBox1.TabIndex = 1        Me.TextBox1.Text = "TextBox1"        '        'TextBox2        '        Me.TextBox2.Location = New System.Drawing.Point(26, 384)        Me.TextBox2.Name = "TextBox2"        Me.TextBox2.Size = New System.Drawing.Size(103, 20)        Me.TextBox2.TabIndex = 2        Me.TextBox2.Text = "TextBox2"        '        'TextBox3        '        Me.TextBox3.Location = New System.Drawing.Point(26, 541)        Me.TextBox3.Name = "TextBox3"        Me.TextBox3.TabIndex = 3        Me.TextBox3.Text = "TextBox3"        '        'TextBox4        '        Me.TextBox4.Location = New System.Drawing.Point(26, 725)        Me.TextBox4.Name = "TextBox4"        Me.TextBox4.TabIndex = 4        Me.TextBox4.Text = "TextBox4"        '        'TextBox5        '        Me.TextBox5.Location = New System.Drawing.Point(26, 929)        Me.TextBox5.Name = "TextBox5"        Me.TextBox5.TabIndex = 5        Me.TextBox5.Text = "TextBox5"        '        'TextBox6        '        Me.TextBox6.Location = New System.Drawing.Point(26, 1394)        Me.TextBox6.Name = "TextBox6"        Me.TextBox6.TabIndex = 7        Me.TextBox6.Text = "TextBox6"        '        'UserControl12        '        Me.UserControl12.Location = New System.Drawing.Point(26, 1142)        Me.UserControl12.Name = "UserControl12"        Me.UserControl12.Size = New System.Drawing.Size(103, 27)        Me.UserControl12.TabIndex = 6        '        'MDIChild        '        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)        Me.AutoScroll = True        Me.ClientSize = New System.Drawing.Size(275, 266)        Me.Controls.Add(Me.UserControl12)        Me.Controls.Add(Me.TextBox6)        Me.Controls.Add(Me.TextBox5)        Me.Controls.Add(Me.TextBox4)        Me.Controls.Add(Me.TextBox3)        Me.Controls.Add(Me.TextBox2)        Me.Controls.Add(Me.TextBox1)        Me.Controls.Add(Me.UserControl11)        Me.Name = "MDIChild"        Me.Text = "MDIChild"        Me.ResumeLayout(False)    End Sub#End RegionEnd Class
    9. In Solution Explorer, right-click user_control_scroll_UI, point to Add, and then click Add New Item.

      The Add New Item - user_control_scroll_UI dialog box appears.
    10. In the Name box, type Mdi.vb, and then click Open.

      The file that is named Mdi.vb appears.
    11. In Solution Explorer, right-click the form that is named Mdi.vb, and then click View Code.
    12. Replace the existing code with the following code:
      Option Strict OnOption Explicit On Public Class MDI    Inherits System.Windows.Forms.Form#Region " Windows Forms Designer generated code "    Public Sub New()        MyBase.New()        'This call is required by the Windows Forms Designer.        InitializeComponent()        'Add any initialization after the InitializeComponent() call.    End Sub    'The 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    'This is required by the Windows Forms Designer.    Private components As System.ComponentModel.IContainer    'Note The following procedure is required by the Windows Forms Designer    'The following procedure can be modified by using the Windows Forms Designer.      'Do not modify the following procedure by using the code editor.    Friend WithEvents MainMenu1 As System.Windows.Forms.MainMenu    Friend WithEvents mnuAutoScroll As System.Windows.Forms.MenuItem    Friend WithEvents mnuVScroll As System.Windows.Forms.MenuItem    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()        Me.MainMenu1 = New System.Windows.Forms.MainMenu        Me.mnuAutoScroll = New System.Windows.Forms.MenuItem        Me.mnuVScroll = New System.Windows.Forms.MenuItem        '        'MainMenu1        '        Me.MainMenu1.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnuAutoScroll, Me.mnuVScroll})        '        'mnuAutoScroll        '        Me.mnuAutoScroll.Index = 0        Me.mnuAutoScroll.Text = "Load AutoScroll Child"        '        'mnuVScroll        '        Me.mnuVScroll.Index = 1        Me.mnuVScroll.Text = "Load VScroll Child"        '        'MDI        '        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)        Me.ClientSize = New System.Drawing.Size(366, 299)        Me.IsMdiContainer = True        Me.Menu = Me.MainMenu1        Me.Name = "MDI"        Me.Text = "MDI"    End Sub#End Region    Private Sub MDI_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load    End Sub    Private Sub mnuAutoScroll_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnuAutoScroll.Click        Dim currentForm As New MDIChild        currentForm.MdiParent = Me        currentForm.WindowState = FormWindowState.Maximized        currentForm.Show()        currentForm.BringToFront()    End Sub    Private Sub mnuVScroll_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnuVScroll.Click        Dim currentForm As New VScrollChild        currentForm.MdiParent = Me        currentForm.WindowState = FormWindowState.Maximized        currentForm.Show()        currentForm.BringToFront()    End SubEnd Class
    13. In Solution Explorer, right-click user_control_scroll_UI, point to Add, and then click Add New Item.

      The Add New Item - user_control_scroll_UI dialog box appears.
    14. In the Name box, type Vscroll.vb, and then click Open.

      The file that is named Vscroll.vb appears.
    15. In Solution Explorer, right-click the form that is named Vscroll.vb, and then click View Code.
    16. Replace the existing code with the following code:
      ption Strict OnOption Explicit On Public Class VScrollChild    Inherits System.Windows.Forms.Form#Region " Windows Forms Designer generated code "    Public Sub New()        MyBase.New()        'This call is required by the Windows Forms Designer.        InitializeComponent()        'Add any initialization after the InitializeComponent() call.    End Sub    'The 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    'This is required by the Windows Forms Designer.    Private components As System.ComponentModel.IContainer    'Note The following procedure is required by the Windows Forms Designer.    'The following procedure can be modified by using the Windows Forms Designer.      'Do not modify the following procedure by using the code editor.    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox    Friend WithEvents TextBox3 As System.Windows.Forms.TextBox    Friend WithEvents TextBox4 As System.Windows.Forms.TextBox    Friend WithEvents TextBox5 As System.Windows.Forms.TextBox    Friend WithEvents TextBox6 As System.Windows.Forms.TextBox    Friend WithEvents testUcNum1 As testusercontrol.UserControl1    Friend WithEvents VScrollBar1 As System.Windows.Forms.VScrollBar    Friend WithEvents testUcNum2 As testusercontrol.UserControl1    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()        Me.testUcNum1 = New testusercontrol.UserControl1        Me.TextBox1 = New System.Windows.Forms.TextBox        Me.TextBox2 = New System.Windows.Forms.TextBox        Me.TextBox3 = New System.Windows.Forms.TextBox        Me.TextBox4 = New System.Windows.Forms.TextBox        Me.TextBox5 = New System.Windows.Forms.TextBox        Me.TextBox6 = New System.Windows.Forms.TextBox        Me.VScrollBar1 = New System.Windows.Forms.VScrollBar        Me.testUcNum2 = New testusercontrol.UserControl1        Me.SuspendLayout()        '        'testUcNum1        '        Me.testUcNum1.Location = New System.Drawing.Point(26, 30)        Me.testUcNum1.Name = "testUcNum1"        Me.testUcNum1.Size = New System.Drawing.Size(104, 24)        Me.testUcNum1.TabIndex = 0        '        'TextBox1        '        Me.TextBox1.Location = New System.Drawing.Point(26, 161)        Me.TextBox1.Name = "TextBox1"        Me.TextBox1.TabIndex = 1        Me.TextBox1.Text = "TextBox1"        '        'TextBox2        '        Me.TextBox2.Location = New System.Drawing.Point(26, 384)        Me.TextBox2.Name = "TextBox2"        Me.TextBox2.Size = New System.Drawing.Size(103, 20)        Me.TextBox2.TabIndex = 2        Me.TextBox2.Text = "TextBox2"        '        'TextBox3        '        Me.TextBox3.Location = New System.Drawing.Point(26, 541)        Me.TextBox3.Name = "TextBox3"        Me.TextBox3.TabIndex = 3        Me.TextBox3.Text = "TextBox3"        '        'TextBox4        '        Me.TextBox4.Location = New System.Drawing.Point(26, 725)        Me.TextBox4.Name = "TextBox4"        Me.TextBox4.TabIndex = 4        Me.TextBox4.Text = "TextBox4"        '        'TextBox5        '        Me.TextBox5.Location = New System.Drawing.Point(26, 929)        Me.TextBox5.Name = "TextBox5"        Me.TextBox5.TabIndex = 5        Me.TextBox5.Text = "TextBox5"        '        'TextBox6        '        Me.TextBox6.Location = New System.Drawing.Point(26, 1394)        Me.TextBox6.Name = "TextBox6"        Me.TextBox6.TabIndex = 7        Me.TextBox6.Text = "TextBox6"        '        'VScrollBar1        '        Me.VScrollBar1.Anchor = CType(((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom) _                    Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)        Me.VScrollBar1.Location = New System.Drawing.Point(224, 0)        Me.VScrollBar1.Name = "VScrollBar1"        Me.VScrollBar1.Size = New System.Drawing.Size(17, 266)        Me.VScrollBar1.TabIndex = 8        '        'testUcNum2        '        Me.testUcNum2.Location = New System.Drawing.Point(27, 639)        Me.testUcNum2.Name = "testUcNum2"        Me.testUcNum2.Size = New System.Drawing.Size(104, 24)        Me.testUcNum2.TabIndex = 9        '        'VScrollChild        '        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)        Me.ClientSize = New System.Drawing.Size(241, 266)        Me.Controls.Add(Me.testUcNum2)        Me.Controls.Add(Me.VScrollBar1)        Me.Controls.Add(Me.TextBox6)        Me.Controls.Add(Me.TextBox5)        Me.Controls.Add(Me.TextBox4)        Me.Controls.Add(Me.TextBox3)        Me.Controls.Add(Me.TextBox2)        Me.Controls.Add(Me.TextBox1)        Me.Controls.Add(Me.testUcNum1)        Me.Name = "VScrollChild"        Me.SizeGripStyle = System.Windows.Forms.SizeGripStyle.Show        Me.Text = "MDIChild"        Me.ResumeLayout(False)    End Sub#End Region    Private htControlTops As New Hashtable    'Note The following assumes that no controls are put above the form the first time. For example, there are no negative .Top values.    '      If this is not the case, a similar "topLine" variable is required to make sure that     '      you know the full length of the useful area of the form.    '                            bottomMostCtl.Top + bottomMostCtl.Height - topMostCtl.Top    '      This calculation is not required on this form.    Private bottomLine As Integer = Integer.MinValue    Private Sub MDIChild_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load        For Each ctl As Control In Me.Controls            If TypeOf ctl Is testusercontrol.UserControl1 _                OrElse TypeOf ctl Is TextBox Then                htControlTops.Add(ctl.Name, ctl.Top)                Debug.WriteLine("MDIChild_Load => Ctl Name: " & ctl.Name & ", Top=" & ctl.Top)                If (ctl.Top + ctl.Height) > bottomLine Then                    bottomLine = ctl.Top + ctl.Height                End If            End If        Next    End Sub    Private Sub VScrollBar1_Scroll(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ScrollEventArgs) Handles VScrollBar1.Scroll        Debug.WriteLine("*** VScrollBar1_Scroll event fired! (New Value: " & e.NewValue & ")")        ScrollForMe(e.NewValue)    End Sub    Private Sub ScrollForMe(ByVal scrollValue As Integer)        Dim oldTop As Integer        Dim pct As Double = scrollValue / VScrollBar1.Maximum        'Debug.WriteLine(">>> Percentage Scroll: " & Format(pct, "00.0%") & " <<<")        Dim incr As Integer = CInt(pct * bottomLine)        'Debug.WriteLine(">>> Increment value: " & incr & " <<<")        For Each ctl As Control In Me.Controls            If TypeOf ctl Is testusercontrol.UserControl1 _                OrElse TypeOf ctl Is TextBox Then                oldTop = CType(htControlTops(ctl.Name), Integer)                ctl.Top = oldTop - incr                'Debug.WriteLine("VScrollBar1_Scroll => Ctl Name: " & ctl.Name & ", Top=" & ctl.Top)            End If        Next    End SubEnd Class
  3. Build the solution, and then run the project. To do this, follow these steps:
    1. In Solution Explorer, click Solution 'testusercontrol' (2 projects).
    2. On the Project menu, click Properties.

      The Solution 'testusercontrol' Property Pages dialog box appears.
    3. In the left pane, double-click Startup Project under Common Properties, and then click user_control_scroll_UI.
    4. In the left pane, double-click Project Dependencies under Common Properties.
    5. In the right pane, click testusercontrol in the Project list, and then click OK.
    6. In Solution Explorer, right-click user_control_scroll_UI, and then click Properties.

      The user_control_scroll_UI Property Pages dialog box appears.
    7. In the left pane, double-click General under Common Properties.
    8. In the right pane, click MDI in the Startup object box.
    9. On the Build menu, click Build Solution.
    10. Press F5 to run the program.

      The MDI form appears.
    11. Click Load AutoScroll Child, click the scroll-down arrow to try to move through the form.

      You notice the behavior that is mentioned in the "Symptoms" section.
REFERENCES
For additional information about creating MDI child forms, visit the following Microsoft Developer Network (MSDN) Web site:For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
824684Description of the standard terminology that is used to describe Microsoft software updates
Właściwości

Identyfikator artykułu: 839577 — ostatni przegląd: 01/17/2015 08:49:31 — zmiana: 2.2

  • Microsoft .NET Framework 1.1
  • kbnosurvey kbarchive kbqfe kbhotfixserver kbmdi kbnetframe110sp1fix kbscrollbar kbcontrol kbforms kbbug kbfix kbnetframe110presp1fix KB839577
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