Change the thumb colour of a trackbar in winforms vb.net

Question

Hi,
I have a requirement to change the thumb colour of trackbar from blue to orange. Is it possible to change the thumb colour and please give a solution for that.

Answer 1

It can be customized with Custom Draw

I have just drawn an orange rectangle for this test to simplify, but you can draw any shape or any bitmap : Trackbar.jpg

Public Class TrackBarCustom
    Inherits TrackBar    

    Private Const TBCD_TICS = &H1
    Private Const TBCD_THUMB = &H2
    Private Const TBCD_CHANNEL = &H3

    <StructLayout(LayoutKind.Sequential)>
    Private Structure NMHDR
        Public hwndFrom As IntPtr
        Public idFrom As IntPtr
        Public code As Integer
    End Structure

    <StructLayout(LayoutKind.Sequential)>
    Friend Structure RECT
        Public left As Integer
        Public top As Integer
        Public right As Integer
        Public bottom As Integer
    End Structure

    <StructLayout(LayoutKind.Sequential)>
    Private Structure NMCUSTOMDRAW
        Public hdr As NMHDR
        Public dwDrawStage As Integer
        Public hdc As IntPtr
        Public rc As RECT
        Public dwItemSpec As IntPtr
        Public uItemState As UInteger
        Public lItemlParam As IntPtr
    End Structure

    <FlagsAttribute>
    Friend Enum CDRF
        CDRF_DODEFAULT = &H0
        CDRF_NEWFONT = &H2
        CDRF_SKIPDEFAULT = &H4
        CDRF_DOERASE = &H8
        CDRF_SKIPPOSTPAINT = &H100
        CDRF_NOTIFYPOSTPAINT = &H10
        CDRF_NOTIFYITEMDRAW = &H20
        CDRF_NOTIFYSUBITEMDRAW = &H20
        CDRF_NOTIFYPOSTERASE = &H40
    End Enum

    <FlagsAttribute>
    Friend Enum CDDS
        CDDS_PREPAINT = &H1
        CDDS_POSTPAINT = &H2
        CDDS_PREERASE = &H3
        CDDS_POSTERASE = &H4
        CDDS_ITEM = &H10000
        CDDS_ITEMPREPAINT = (CDDS_ITEM Or CDDS_PREPAINT)
        CDDS_ITEMPOSTPAINT = (CDDS_ITEM Or CDDS_POSTPAINT)
        CDDS_ITEMPREERASE = (CDDS_ITEM Or CDDS_PREERASE)
        CDDS_ITEMPOSTERASE = (CDDS_ITEM Or CDDS_POSTERASE)
        CDDS_SUBITEM = &H20000
    End Enum


    <DllImport("User32.dll", SetLastError:=True)>
    Private Shared Function FillRect(ByVal hDC As IntPtr, ByRef lpRect As RECT, ByVal hBR As IntPtr) As IntPtr
    End Function

    <DllImport("Gdi32.dll", SetLastError:=True)>
    Public Shared Function CreateSolidBrush(crColor As Integer) As Integer
    End Function

    <DllImport("Gdi32.dll", SetLastError:=True)>
    Public Shared Function DeleteObject(hObject As IntPtr) As Boolean
    End Function

    Protected Overrides Sub WndProc(ByRef m As Message)
        If m.Msg = WM_REFLECT + WM_NOFITY Then
            Dim pnmhdr = CType(m.GetLParam(GetType(NMHDR)), NMHDR)
            If pnmhdr.code = NM_CUSTOMDRAW Then
                Dim pnmlv = CType(m.GetLParam(GetType(NMCUSTOMDRAW)), NMCUSTOMDRAW)
                Select Case pnmlv.dwDrawStage
                    Case CDDS.CDDS_PREPAINT
                        m.Result = New IntPtr(CDRF.CDRF_NOTIFYITEMDRAW)
                    Case CDDS.CDDS_ITEMPREPAINT
                        If (pnmlv.dwItemSpec = TBCD_THUMB) Then
                            Dim hBrush As IntPtr = CreateSolidBrush(ColorTranslator.ToWin32(Color.Orange))
                            FillRect(pnmlv.hdc, pnmlv.rc, hBrush)
                            DeleteObject(hBrush)
                            m.Result = New IntPtr(CDRF.CDRF_SKIPDEFAULT)
                        Else
                            m.Result = New IntPtr(CDRF.CDRF_NOTIFYPOSTPAINT)
                        End If
                    Case CDDS.CDDS_ITEMPOSTPAINT
                        m.Result = New IntPtr(CDRF.CDRF_DODEFAULT)
                End Select
            End If
            Return
        Else
            MyBase.WndProc(m)
        End If
    End Sub

    Private Const NM_FIRST As Integer = 0
    Private Const NM_CLICK As Integer = NM_FIRST - 2
    Private Const NM_CUSTOMDRAW As Integer = NM_FIRST - 12
    Private Const WM_REFLECT As Integer = &H2000
    Private Const WM_NOFITY As Integer = &H4E
End Class