SplitContainer中的顶部ListView不会添加垂直滚动条

我有一个在SplitContainer中带有两个ListViews的Winforms应用程序。

当我拖动拆分器以隐藏Panel2 ListView项目的一部分时，它会自动添加垂直滚动条。

当我拖动拆分器以隐藏Panel1 ListView项目的一部分时，它不会添加垂直滚动条。

更改哪个ListView在哪个Panel中具有相同的行为。好像有关SplitContainer或其面板的某些事情正在控制是否将垂直滚动条添加到Panel1中的ListView中。如何使顶部Panel1中的哪个ListView也自动添加垂直滚动条？

若要进行复制，请使用一个表单创建一个简单的Winforms应用程序。这是我的表单代码，然后是设计者表单代码。

Public Class Form1
    Private Sub Form1_Shown(sender As Object, e As EventArgs) Handles Me.Shown
        Timer1.Enabled = True
    End Sub

    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
        Try
            Timer1.Enabled = False

            TechDateList.BeginUpdate()
            TechDateList.Items.Clear()
            StopsList.BeginUpdate()
            StopsList.Items.Clear()

            For i As Integer = 1 To 5
                Dim techItem = New ListViewItem
                techItem.UseItemStyleForSubItems = False
                techItem.SubItems(0).Text = Date.Now.ToString("MMM dd, yyyy")
                techItem.SubItems.Add(String.Format("Tech {0}", i))
                TechDateList.Items.Add(techItem)
            Next

            For i As Integer = 1 To 5
                Dim stopItem = New ListViewItem
                stopItem.UseItemStyleForSubItems = False
                stopItem.SubItems(0).Text = Choose(i, "AAA", "BBB", "CCC", "DDD", "EEE")
                stopItem.SubItems.Add(String.Format("Stop {0}", i))
                StopsList.Items.Add(stopItem)
            Next
        Catch ex As Exception
            MsgBox(ex.ToString(), MsgBoxStyle.Critical + MsgBoxStyle.OkOnly, "Timer1_Tick Error 1")
        Finally
            TechDateList.EndUpdate()
            StopsList.EndUpdate()
        End Try

        Try
            ListSplitter.Panel1Collapsed = False
            ListSplitter.SplitterDistance = 125
            ListSplitter.SplitterWidth = 6
            TechDateList.Items.Item(0).Selected = True
        Catch ex As Exception
            MsgBox(ex.ToString(), MsgBoxStyle.Critical + MsgBoxStyle.OkOnly, "Timer1_Tick Error 2")
        End Try
    End Sub
End Class

<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Partial Class Form1
    Inherits System.Windows.Forms.Form

    'Form overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        Try
            If disposing AndAlso components IsNot Nothing Then
                components.Dispose()
            End If
        Finally
            MyBase.Dispose(disposing)
        End Try
    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.
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.components = New System.ComponentModel.Container()
        Me.ListSplitter = New System.Windows.Forms.SplitContainer()
        Me.TechDateList = New System.Windows.Forms.ListView()
        Me.UInitial = CType(New System.Windows.Forms.ColumnHeader(), System.Windows.Forms.ColumnHeader)
        Me.SchedDate = CType(New System.Windows.Forms.ColumnHeader(), System.Windows.Forms.ColumnHeader)
        Me.StopsList = New System.Windows.Forms.ListView()
        Me.StopNum = CType(New System.Windows.Forms.ColumnHeader(), System.Windows.Forms.ColumnHeader)
        Me.StopName = CType(New System.Windows.Forms.ColumnHeader(), System.Windows.Forms.ColumnHeader)
        Me.Timer1 = New System.Windows.Forms.Timer(Me.components)
        CType(Me.ListSplitter, System.ComponentModel.ISupportInitialize).BeginInit()
        Me.ListSplitter.Panel1.SuspendLayout()
        Me.ListSplitter.Panel2.SuspendLayout()
        Me.ListSplitter.SuspendLayout()
        Me.SuspendLayout()
        '
        'ListSplitter
        '
        Me.ListSplitter.Dock = System.Windows.Forms.DockStyle.Fill
        Me.ListSplitter.FixedPanel = System.Windows.Forms.FixedPanel.Panel1
        Me.ListSplitter.Location = New System.Drawing.Point(0, 0)
        Me.ListSplitter.Name = "ListSplitter"
        Me.ListSplitter.Orientation = System.Windows.Forms.Orientation.Horizontal
        '
        'ListSplitter.Panel1
        '
        Me.ListSplitter.Panel1.Controls.Add(Me.TechDateList)
        Me.ListSplitter.Panel1Collapsed = True
        Me.ListSplitter.Panel1MinSize = 0
        '
        'ListSplitter.Panel2
        '
        Me.ListSplitter.Panel2.Controls.Add(Me.StopsList)
        Me.ListSplitter.Size = New System.Drawing.Size(384, 261)
        Me.ListSplitter.SplitterDistance = 25
        Me.ListSplitter.SplitterWidth = 1
        Me.ListSplitter.TabIndex = 1
        '
        'TechDateList
        '
        Me.TechDateList.Anchor = CType(((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom) _
            Or System.Windows.Forms.AnchorStyles.Left), System.Windows.Forms.AnchorStyles)
        Me.TechDateList.Columns.AddRange(New System.Windows.Forms.ColumnHeader() {Me.UInitial, Me.SchedDate})
        Me.TechDateList.FullRowSelect = True
        Me.TechDateList.HeaderStyle = System.Windows.Forms.ColumnHeaderStyle.None
        Me.TechDateList.HideSelection = False
        Me.TechDateList.LabelWrap = False
        Me.TechDateList.Location = New System.Drawing.Point(4, 0)
        Me.TechDateList.Margin = New System.Windows.Forms.Padding(0)
        Me.TechDateList.MultiSelect = False
        Me.TechDateList.Name = "TechDateList"
        Me.TechDateList.ShowGroups = False
        Me.TechDateList.Size = New System.Drawing.Size(258, 166)
        Me.TechDateList.TabIndex = 0
        Me.TechDateList.UseCompatibleStateImageBehavior = False
        Me.TechDateList.View = System.Windows.Forms.View.Details
        '
        'UInitial
        '
        Me.UInitial.Text = "Route"
        Me.UInitial.TextAlign = System.Windows.Forms.HorizontalAlignment.Center
        Me.UInitial.Width = 100
        '
        'SchedDate
        '
        Me.SchedDate.Text = "Job Date"
        Me.SchedDate.Width = 133
        '
        'StopsList
        '
        Me.StopsList.Anchor = CType(((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom) _
            Or System.Windows.Forms.AnchorStyles.Left), System.Windows.Forms.AnchorStyles)
        Me.StopsList.Columns.AddRange(New System.Windows.Forms.ColumnHeader() {Me.StopNum, Me.StopName})
        Me.StopsList.FullRowSelect = True
        Me.StopsList.HeaderStyle = System.Windows.Forms.ColumnHeaderStyle.None
        Me.StopsList.HideSelection = False
        Me.StopsList.LabelWrap = False
        Me.StopsList.Location = New System.Drawing.Point(4, 0)
        Me.StopsList.Margin = New System.Windows.Forms.Padding(0)
        Me.StopsList.MultiSelect = False
        Me.StopsList.Name = "StopsList"
        Me.StopsList.ShowGroups = False
        Me.StopsList.Size = New System.Drawing.Size(258, 252)
        Me.StopsList.TabIndex = 0
        Me.StopsList.UseCompatibleStateImageBehavior = False
        Me.StopsList.View = System.Windows.Forms.View.Details
        '
        'StopNum
        '
        Me.StopNum.Text = "000"
        Me.StopNum.TextAlign = System.Windows.Forms.HorizontalAlignment.Center
        Me.StopNum.Width = 34
        '
        'StopName
        '
        Me.StopName.Text = "Stop Name"
        Me.StopName.Width = 199
        '
        'Timer1
        '
        Me.Timer1.Interval = 250
        '
        'Form1
        '
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(384, 261)
        Me.Controls.Add(Me.ListSplitter)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ListSplitter.Panel1.ResumeLayout(False)
        Me.ListSplitter.Panel2.ResumeLayout(False)
        CType(Me.ListSplitter, System.ComponentModel.ISupportInitialize).EndInit()
        Me.ListSplitter.ResumeLayout(False)
        Me.ResumeLayout(False)

    End Sub

    Friend WithEvents ListSplitter As SplitContainer
    Friend WithEvents TechDateList As ListView
    Friend WithEvents UInitial As ColumnHeader
    Friend WithEvents SchedDate As ColumnHeader
    Friend WithEvents StopsList As ListView
    Friend WithEvents StopNum As ColumnHeader
    Friend WithEvents StopName As ColumnHeader
    Friend WithEvents Timer1 As Timer
End Class