秘訣は、TrackBarコントロールをサブクラス化し、OnPaintBackgroundイベントとOnPaintイベントを処理することです。これは、私が自分のプロジェクトのいくつかで使用しているコントロールの「エクストラライト」バージョンです。
このバージョンはかなり制限されていますが、始めるのに役立つはずです...
Imports System.Drawing.Drawing2D
Public Class CoolTrackBar
Inherits TrackBar
Private thumbRect As Rectangle = New Rectangle(0, 0, 19, 19)
Private isOverThumb As Boolean
Private cachedValue As Integer
Private rangeRect As Rectangle = Rectangle.Empty
Private mGrooveSize As Integer = 6
Private mGrooveBorderColor As Color = Color.Gray
Private mGrooveColor As Color = Color.LightGray
Private mSelStartColor As Color = Color.Blue
Private mSelEndColor As Color = Color.Red
Public Sub New()
Me.SetStyle(ControlStyles.AllPaintingInWmPaint, True)
Me.SetStyle(ControlStyles.OptimizedDoubleBuffer, True)
Me.SetStyle(ControlStyles.ResizeRedraw, True)
Me.SetStyle(ControlStyles.UserPaint, True)
Me.SetStyle(ControlStyles.SupportsTransparentBackColor, True)
End Sub
Public Property GrooveSize As Integer
Get
Return mGrooveSize
End Get
Set(value As Integer)
mGrooveSize = value
Me.Invalidate()
End Set
End Property
Public Property GrooveColor As Color
Get
Return mGrooveColor
End Get
Set(value As Color)
mGrooveColor = value
Me.Invalidate()
End Set
End Property
Public Property GrooveBorderColor As Color
Get
Return mGrooveBorderColor
End Get
Set(value As Color)
mGrooveBorderColor = value
Me.Invalidate()
End Set
End Property
Public Overloads Property TickStyle As TickStyle
Get
Return Windows.Forms.TickStyle.Both
End Get
Set(value As TickStyle)
MyBase.TickStyle = Windows.Forms.TickStyle.Both
End Set
End Property
Protected Overrides Sub OnPaintBackground(pevent As PaintEventArgs)
Dim g As Graphics = pevent.Graphics
Dim r As Rectangle = Me.DisplayRectangle
Select Case MyBase.Orientation
Case Orientation.Horizontal
rangeRect = New Rectangle(r.X + 14, r.Top, r.Width - 30, r.Height)
Case Orientation.Vertical
rangeRect = New Rectangle(r.X + 5, r.Y + 14, r.Width, r.Height - 29)
End Select
MyBase.OnPaintBackground(pevent)
DrawGroove(g)
End Sub
Protected Overrides Sub OnPaint(e As PaintEventArgs)
Dim g As Graphics = e.Graphics
DrawThumb(g)
End Sub
Private Sub DrawGroove(g As Graphics)
Dim r1 As Rectangle
Dim r2 As Rectangle
Select Case Orientation
Case Windows.Forms.Orientation.Horizontal
r1 = New Rectangle(rangeRect.X, rangeRect.Y + (rangeRect.Height - mGrooveSize) \ 2, rangeRect.Width, mGrooveSize)
r2 = New Rectangle(r1.X, r1.Y, r1.Width * ValueToPercentage(cachedValue), r1.Height)
Case Windows.Forms.Orientation.Vertical
r1 = New Rectangle(rangeRect.X + (rangeRect.Width - mGrooveSize) / 2 - mGrooveSize \ 2, rangeRect.Y, mGrooveSize, rangeRect.Height)
r2 = New Rectangle(r1.X, r1.Y, r1.Width, r1.Height * ValueToPercentage(cachedValue))
End Select
Using b As New SolidBrush(mGrooveColor)
g.FillRectangle(b, r1)
End Using
Using p As New Pen(mGrooveBorderColor)
g.DrawRectangle(p, r1)
End Using
Using lgb As New LinearGradientBrush(r1.Location, New Point(r1.Right, r1.Bottom), mSelStartColor, mSelEndColor)
g.FillRectangle(lgb, r2)
End Using
End Sub
Private Sub DrawThumb(g As Graphics)
Dim thumb As VisualStyles.VisualStyleElement = Nothing
Select Case MyBase.Orientation
Case Orientation.Horizontal
If MyBase.Enabled Then
If isOverThumb Then
thumb = VisualStyles.VisualStyleElement.TrackBar.ThumbTop.Hot
Else
If MyBase.Focused Then
thumb = VisualStyles.VisualStyleElement.TrackBar.ThumbTop.Focused
Else
thumb = VisualStyles.VisualStyleElement.TrackBar.ThumbTop.Normal
End If
End If
Else
thumb = VisualStyles.VisualStyleElement.TrackBar.ThumbTop.Disabled
End If
Case Orientation.Vertical
If MyBase.Enabled Then
If isOverThumb Then
thumb = VisualStyles.VisualStyleElement.TrackBar.ThumbRight.Hot
Else
If MyBase.Focused Then
thumb = VisualStyles.VisualStyleElement.TrackBar.ThumbRight.Focused
Else
thumb = VisualStyles.VisualStyleElement.TrackBar.ThumbRight.Normal
End If
End If
Else
thumb = VisualStyles.VisualStyleElement.TrackBar.ThumbRight.Disabled
End If
End Select
Dim valuePercentage As Single = ValueToPercentage(cachedValue)
Dim vsr = New VisualStyles.VisualStyleRenderer(thumb)
thumbRect.Size = vsr.GetPartSize(g, VisualStyles.ThemeSizeType.Draw)
Dim pos As Integer
Select Case MyBase.Orientation
Case Orientation.Horizontal
pos = valuePercentage * rangeRect.Width
thumbRect.Location = New Point(pos + thumbRect.Width / 2 + 3, rangeRect.Y + thumbRect.Height / 2 + mGrooveSize / 4)
Case Orientation.Vertical
pos = valuePercentage * rangeRect.Height
thumbRect.Location = New Point(rangeRect.X + thumbRect.Width / 2 + mGrooveSize / 4, pos + thumbRect.Height / 2 + 3)
End Select
vsr.DrawBackground(g, thumbRect)
End Sub
Private Function ValueToPercentage(value As Integer) As Single
Dim w As Integer = MyBase.Maximum - MyBase.Minimum
Dim min = MyBase.Minimum
Dim max = MyBase.Maximum
If MyBase.Orientation = Orientation.Horizontal Then
Return (value - min) / (max - min)
Else
Return 1 - (value - min) / (max - min)
End If
End Function
Private Sub CoolTrackBar_MouseMove(sender As Object, e As MouseEventArgs) Handles Me.MouseMove
If thumbRect.IntersectsWith(New Rectangle(e.Location, New Size(1, 1))) Then
isOverThumb = True
Me.Invalidate()
ElseIf isOverThumb Then
isOverThumb = False
Me.Invalidate()
End If
End Sub
Private Sub CoolTrackBar_ValueChanged(sender As Object, e As EventArgs) Handles Me.ValueChanged
cachedValue = MyBase.Value
Me.Invalidate()
End Sub
End Class
これを使用するには、WinFormsプロジェクトを作成してから、新しいプロジェクトを作成しClass
、名前CoolTrackBar
を付けて、上記のコードを貼り付けます。コントロールをツールボックスに表示するには、ソリューションをコンパイルする必要があります。