ListBoxのオーナードロー(OwnerDrawVariable)でスクロールが逆方向に見える

    Private Sub ListBox1_MeasureItem(ByVal sender As Object, ByVal e As System.Windows.Forms.MeasureItemEventArgs) Handles ListBox1.MeasureItem

        e.ItemHeight = 15

    End Sub



    Private Sub ListBox1_DrawItem(ByVal sender As Object, ByVal e As System.Windows.Forms.DrawItemEventArgs) Handles ListBox1.DrawItem

        If e.Index < 0 Then Exit Sub



        If ListBox1.SelectedIndex = e.Index Then

            e.Graphics.FillRectangle(Brushes.Aqua, e.Bounds)

        Else

            e.Graphics.FillRectangle(Brushes.LightGray, e.Bounds)

        End If

        e.Graphics.DrawString(e.Index.ToString, ListBox1.Font, Brushes.Black, e.Bounds.X + 10, e.Bounds.Y + 1)





    End Sub



    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load



        For i As Integer = 0 To 99

            ListBox1.Items.Add(i)

        Next

        ListBox1.SelectedIndex = 0



    End Sub



    Private Sub ListBox1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged

        ListBox1.Invalidate()

    End Sub

Imports System.Runtime.InteropServices



Public Class myListBox

    Inherits System.Windows.Forms.ListBox



+#Region " Windows フォーム デザイナで生成されたコード "



    Const WM_VSCROLL As Integer = &H115I

    Const WM_PAINT As Integer = &HFI

    Const WM_SETREDRAW As Integer = &HBI



    Const SB_LINEUP As Short = &H0S

    Const SB_LINELEFT As Short = &H0S

    Const SB_LINEDOWN As Short = &H1S

    Const SB_LINERIGHT As Short = &H1S

    Const SB_PAGEUP As Short = &H2S

    Const SB_PAGELEFT As Short = &H2S

    Const SB_PAGEDOWN As Short = &H3S

    Const SB_PAGERIGHT As Short = &H3S

    Const SB_THUMBPOSITION As Short = &H4S

    Const SB_THUMBTRACK As Short = &H5S

    Const SB_TOP As Short = &H6S

    Const SB_LEFT As Short = &H6S

    Const SB_BOTTOM As Short = &H7S

    Const SB_RIGHT As Short = &H7S

    Const SB_ENDSCROLL As Short = &H8S



    <StructLayout(LayoutKind.Sequential)> Public Structure SCROLLINFO

        Public cbSize As Integer

        Public fMask As Integer

        Public nMin As Integer

        Public nMax As Integer

        Public nPage As Integer

        Public nPos As Integer

        Public nTrackPos As Integer

    End Structure



    Private Const SB_HORZ = 0    '標準水平スクロールバーを指定する

    Private Const SB_VERT = 1     '標準垂直スクロールバーを指定する

    Private Const SB_CTL = 2     'スクロールバーコントロールを指定する



    Private Const SIF_RANGE = &H1

    Private Const SIF_PAGE = &H2

    Private Const SIF_POS = &H4

    Private Const SIF_DISABLENOSCROLL = &H8

    Private Const SIF_TRACKPOS = &H10

    Private Const SIF_ALL = (SIF_RANGE Or SIF_PAGE Or SIF_POS Or SIF_TRACKPOS)



    <DllImport("user32.dll")> _

    Private Shared Function GetScrollInfo(ByVal hWnd As IntPtr, _

                                        ByVal nBar As Integer, _

        <MarshalAs(UnmanagedType.Struct)> ByRef lpScrollInfo As SCROLLINFO) As Integer

    End Function



    <DllImport("user32.dll")> _

    Private Shared Function SetScrollInfo(ByVal hWnd As IntPtr, _

                                        ByVal nBar As Integer, _

        <MarshalAs(UnmanagedType.Struct)> ByRef lpScrollInfo As SCROLLINFO) As Integer

    End Function



    <DllImport("user32.dll")> _

    Private Shared Function SendMessage(ByVal hWnd As IntPtr, _

                                        ByVal msg As Int32, _

                                        ByVal wParam As Int32, _

                                        ByVal lParam As IntPtr) As Int32

    End Function



    <DllImport("user32.dll")> _

    Private Shared Function GetScrollRange(ByVal hWnd As IntPtr, _

                                            ByVal nBar As Integer, _

                                            ByRef MinPos As Integer, _

                                            ByRef MaxPos As Integer) As Integer

    End Function



    Private Structure POINT

        Public x As Integer

        Public y As Integer

    End Structure



    Protected Overrides Sub WndProc(ByRef m As Message)

        Select Case m.Msg

            Case WM_VSCROLL



                SendMessage(m.HWnd, WM_SETREDRAW, False, New IntPtr(0))

                MyBase.WndProc(m)

                SendMessage(m.HWnd, WM_SETREDRAW, True, New IntPtr(0))

                MyBase.Invalidate()



                'なぜかスクロールバーが同期しないのでSetScrollInfo

                Dim scInfo As SCROLLINFO

                scInfo.cbSize = Marshal.SizeOf(scInfo)

                scInfo.fMask = SIF_POS

                GetScrollInfo(m.HWnd, SB_VERT, scInfo)

                SetScrollInfo(m.HWnd, SB_VERT, scInfo)



                Exit Sub

        End Select

        MyBase.WndProc(m)

    End Sub



    Protected Overrides Sub OnMeasureItem(ByVal e As System.Windows.Forms.MeasureItemEventArgs)

        e.ItemHeight = 15

    End Sub



    Protected Overrides Sub OnDrawItem(ByVal e As System.Windows.Forms.DrawItemEventArgs)

        If e.Index < 0 Then Exit Sub



        If MyBase.SelectedIndex = e.Index Then

            e.Graphics.FillRectangle(Brushes.Aqua, e.Bounds)

        Else

            e.Graphics.FillRectangle(Brushes.LightGray, e.Bounds)

        End If

        e.Graphics.DrawString(e.Index.ToString, MyBase.Font, Brushes.Black, e.Bounds.X + 10, e.Bounds.Y + 1)



    End Sub





    Protected Overrides Sub OnSelectedIndexChanged(ByVal e As System.EventArgs)

        MyBase.Invalidate()

    End Sub





End Class

    Case WM_VSCROLL

        MyBase.Visible = False

        MyBase.WndProc(m)

        MyBase.Visible = True