TrackBarRenderer 類別
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
提供用來呈現具有視覺化樣式之追蹤列控制項的方法。 此類別無法獲得繼承。
public ref class TrackBarRenderer sealedpublic ref class TrackBarRenderer abstract sealedpublic sealed class TrackBarRendererpublic static class TrackBarRenderertype TrackBarRenderer = classPublic NotInheritable Class TrackBarRendererPublic Class TrackBarRenderer- 繼承
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TrackBarRenderer
範例
下列程式碼範例示範如何建立自訂控制項，以使用 TrackBarRenderer 方法來繪製可回應滑鼠點選的水準追蹤列。
#using <System.Drawing.dll>
#using <System.Windows.Forms.dll>
#using <System.dll>
using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
using namespace System::Windows::Forms::VisualStyles;
namespace TrackBarRendererSample
{
ref class CustomTrackBar : public Control
{
private:
int numberTicks;
Rectangle trackRectangle;
Rectangle ticksRectangle;
Rectangle thumbRectangle;
int currentTickPosition;
float tickSpace;
bool thumbClicked;
TrackBarThumbState thumbState;
public:
CustomTrackBar(int ticks, System::Drawing::Size trackBarSize)
{
this->Location = Point(10, 10);
this->Size = trackBarSize;
this->numberTicks = ticks;
this->BackColor = Color::DarkCyan;
this->DoubleBuffered = true;
numberTicks = 10;
thumbState = TrackBarThumbState::Normal;
// Calculate the initial sizes of the bar,
// thumb and ticks.
SetupTrackBar();
}
// Calculate the sizes of the bar, thumb, and ticks rectangle.
private:
void SetupTrackBar()
{
if (!TrackBarRenderer::IsSupported)
{
return;
}
Graphics^ g = this->CreateGraphics();
// Calculate the size of the track bar.
trackRectangle.X = ClientRectangle.X + 2;
trackRectangle.Y = ClientRectangle.Y + 28;
trackRectangle.Width = ClientRectangle.Width - 4;
trackRectangle.Height = 4;
// Calculate the size of the rectangle in which to
// draw the ticks.
ticksRectangle.X = trackRectangle.X + 4;
ticksRectangle.Y = trackRectangle.Y - 8;
ticksRectangle.Width = trackRectangle.Width - 8;
ticksRectangle.Height = 4;
tickSpace = ((float)ticksRectangle.Width - 1) /
((float)numberTicks - 1);
// Calculate the size of the thumb.
thumbRectangle.Size =
TrackBarRenderer::GetTopPointingThumbSize(g,
TrackBarThumbState::Normal);
thumbRectangle.X = CurrentTickXCoordinate();
thumbRectangle.Y = trackRectangle.Y - 8;
}
private:
int CurrentTickXCoordinate()
{
if (tickSpace == 0)
{
return 0;
}
else
{
return ((int)Math::Round(tickSpace) *
currentTickPosition);
}
}
// Draw the track bar.
protected:
virtual void OnPaint(PaintEventArgs^ e) override
{
if (!TrackBarRenderer::IsSupported)
{
this->Parent->Text = "CustomTrackBar Disabled";
return;
}
this->Parent->Text = "CustomTrackBar Enabled";
TrackBarRenderer::DrawHorizontalTrack(e->Graphics,
trackRectangle);
TrackBarRenderer::DrawTopPointingThumb(e->Graphics,
thumbRectangle, thumbState);
TrackBarRenderer::DrawHorizontalTicks(e->Graphics,
ticksRectangle, numberTicks, EdgeStyle::Raised);
}
// Determine whether the user has clicked the track bar thumb.
protected:
virtual void OnMouseDown(MouseEventArgs^ e) override
{
if (!TrackBarRenderer::IsSupported)
{
return;
}
if (this->thumbRectangle.Contains(e->Location))
{
thumbClicked = true;
thumbState = TrackBarThumbState::Pressed;
}
this->Invalidate();
}
// Redraw the track bar thumb if the user has moved it.
protected:
virtual void OnMouseUp(MouseEventArgs^ e) override
{
if (!TrackBarRenderer::IsSupported)
{
return;
}
if (thumbClicked == true)
{
if (e->Location.X > trackRectangle.X &&
e->Location.X < (trackRectangle.X +
trackRectangle.Width - thumbRectangle.Width))
{
thumbClicked = false;
thumbState = TrackBarThumbState::Hot;
this->Invalidate();
}
thumbClicked = false;
}
}
// Track cursor movements.
protected:
virtual void OnMouseMove(MouseEventArgs^ e) override
{
if (!TrackBarRenderer::IsSupported)
{
return;
}
// The user is moving the thumb.
if (thumbClicked == true)
{
// Track movements to the next tick to the right, if
// the cursor has moved halfway to the next tick.
if (currentTickPosition < numberTicks - 1 &&
e->Location.X > CurrentTickXCoordinate() +
(int)(tickSpace))
{
currentTickPosition++;
}
// Track movements to the next tick to the left, if
// cursor has moved halfway to the next tick.
else if (currentTickPosition > 0 &&
e->Location.X < CurrentTickXCoordinate() -
(int)(tickSpace / 2))
{
currentTickPosition--;
}
thumbRectangle.X = CurrentTickXCoordinate();
}
// The cursor is passing over the track.
else
{
if (thumbRectangle.Contains(e->Location))
{
thumbState = TrackBarThumbState::Hot;
}
else
{
thumbState = TrackBarThumbState::Normal;
}
}
Invalidate();
}
};
ref class Form1 : public Form
{
public:
Form1()
{
CustomTrackBar^ TrackBar1 = gcnew CustomTrackBar(19,
System::Drawing::Size(300, 50));
this->Width = 500;
this->Controls->Add(TrackBar1);
}
};
}
[STAThread]
int main()
{
// Note that the call to EnableVisualStyles below does
// not affect whether TrackBarRenderer.IsSupported is true;
// as long as visual styles are enabled by the operating system,
// IsSupported is true.
Application::EnableVisualStyles();
Application::Run(gcnew TrackBarRendererSample::Form1());
return 0;
}
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;
namespace TrackBarRendererSample
{
class Form1 : Form
{
public Form1()
{
CustomTrackBar TrackBar1 = new CustomTrackBar(19,
new Size(300, 50));
this.Width = 500;
this.Controls.Add(TrackBar1);
}
[STAThread]
static void Main()
{
// Note that the call to EnableVisualStyles below does
// not affect whether TrackBarRenderer.IsSupported is true;
// as long as visual styles are enabled by the operating system,
// IsSupported is true.
Application.EnableVisualStyles();
Application.Run(new Form1());
}
}
class CustomTrackBar : Control
{
private int numberTicks = 10;
private Rectangle trackRectangle = new Rectangle();
private Rectangle ticksRectangle = new Rectangle();
private Rectangle thumbRectangle = new Rectangle();
private int currentTickPosition = 0;
private float tickSpace = 0;
private bool thumbClicked = false;
private TrackBarThumbState thumbState =
TrackBarThumbState.Normal;
public CustomTrackBar(int ticks, Size trackBarSize)
{
this.Location = new Point(10, 10);
this.Size = trackBarSize;
this.numberTicks = ticks;
this.BackColor = Color.DarkCyan;
this.DoubleBuffered = true;
// Calculate the initial sizes of the bar,
// thumb and ticks.
SetupTrackBar();
}
// Calculate the sizes of the bar, thumb, and ticks rectangle.
private void SetupTrackBar()
{
if (!TrackBarRenderer.IsSupported)
return;
using (Graphics g = this.CreateGraphics())
{
// Calculate the size of the track bar.
trackRectangle.X = ClientRectangle.X + 2;
trackRectangle.Y = ClientRectangle.Y + 28;
trackRectangle.Width = ClientRectangle.Width - 4;
trackRectangle.Height = 4;
// Calculate the size of the rectangle in which to
// draw the ticks.
ticksRectangle.X = trackRectangle.X + 4;
ticksRectangle.Y = trackRectangle.Y - 8;
ticksRectangle.Width = trackRectangle.Width - 8;
ticksRectangle.Height = 4;
tickSpace = ((float)ticksRectangle.Width - 1) /
((float)numberTicks - 1);
// Calculate the size of the thumb.
thumbRectangle.Size =
TrackBarRenderer.GetTopPointingThumbSize(g,
TrackBarThumbState.Normal);
thumbRectangle.X = CurrentTickXCoordinate();
thumbRectangle.Y = trackRectangle.Y - 8;
}
}
private int CurrentTickXCoordinate()
{
if (tickSpace == 0)
{
return 0;
}
else
{
return ((int)Math.Round(tickSpace) *
currentTickPosition);
}
}
// Draw the track bar.
protected override void OnPaint(PaintEventArgs e)
{
if (!TrackBarRenderer.IsSupported)
{
this.Parent.Text = "CustomTrackBar Disabled";
return;
}
this.Parent.Text = "CustomTrackBar Enabled";
TrackBarRenderer.DrawHorizontalTrack(e.Graphics,
trackRectangle);
TrackBarRenderer.DrawTopPointingThumb(e.Graphics,
thumbRectangle, thumbState);
TrackBarRenderer.DrawHorizontalTicks(e.Graphics,
ticksRectangle, numberTicks, EdgeStyle.Raised);
}
// Determine whether the user has clicked the track bar thumb.
protected override void OnMouseDown(MouseEventArgs e)
{
if (!TrackBarRenderer.IsSupported)
return;
if (this.thumbRectangle.Contains(e.Location))
{
thumbClicked = true;
thumbState = TrackBarThumbState.Pressed;
}
this.Invalidate();
}
// Redraw the track bar thumb if the user has moved it.
protected override void OnMouseUp(MouseEventArgs e)
{
if (!TrackBarRenderer.IsSupported)
return;
if (thumbClicked == true)
{
if (e.Location.X > trackRectangle.X &&
e.Location.X < (trackRectangle.X +
trackRectangle.Width - thumbRectangle.Width))
{
thumbClicked = false;
thumbState = TrackBarThumbState.Hot;
this.Invalidate();
}
thumbClicked = false;
}
}
// Track cursor movements.
protected override void OnMouseMove(MouseEventArgs e)
{
if (!TrackBarRenderer.IsSupported)
return;
// The user is moving the thumb.
if (thumbClicked == true)
{
// Track movements to the next tick to the right, if
// the cursor has moved halfway to the next tick.
if (currentTickPosition < numberTicks - 1 &&
e.Location.X > CurrentTickXCoordinate() +
(int)(tickSpace))
{
currentTickPosition++;
}
// Track movements to the next tick to the left, if
// cursor has moved halfway to the next tick.
else if (currentTickPosition > 0 &&
e.Location.X < CurrentTickXCoordinate() -
(int)(tickSpace / 2))
{
currentTickPosition--;
}
thumbRectangle.X = CurrentTickXCoordinate();
}
// The cursor is passing over the track.
else
{
thumbState = thumbRectangle.Contains(e.Location) ?
TrackBarThumbState.Hot : TrackBarThumbState.Normal;
}
Invalidate();
}
}
}
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Windows.Forms.VisualStyles
Namespace TrackBarRendererSample
Class Form1
Inherits Form
Public Sub New()
Dim TrackBar1 As New CustomTrackBar(19, New Size(300, 50))
Me.Width = 500
Me.Controls.Add(TrackBar1)
End Sub
<STAThread()> _
Shared Sub Main()
' Note that the call to EnableVisualStyles below does
' not affect whether TrackBarRenderer.IsSupported is true;
' as long as visual styles are enabled by the operating system,
' IsSupported is true.
Application.EnableVisualStyles()
Application.Run(New Form1())
End Sub
End Class
Class CustomTrackBar
Inherits Control
Private numberTicks As Integer = 10
Private trackRectangle As New Rectangle()
Private ticksRectangle As New Rectangle()
Private thumbRectangle As New Rectangle()
Private currentTickPosition As Integer = 0
Private tickSpace As Single = 0
Private thumbClicked As Boolean = False
Private thumbState As TrackBarThumbState = TrackBarThumbState.Normal
Public Sub New(ByVal ticks As Integer, ByVal trackBarSize As Size)
With Me
.Location = New Point(10, 10)
.Size = trackBarSize
.numberTicks = ticks
.BackColor = Color.DarkCyan
.DoubleBuffered = True
End With
' Calculate the initial sizes of the bar,
' thumb and ticks.
SetupTrackBar()
End Sub
' Calculate the sizes of the bar, thumb, and ticks rectangle.
Private Sub SetupTrackBar()
If Not TrackBarRenderer.IsSupported Then
Return
End If
Using g As Graphics = Me.CreateGraphics()
' Calculate the size of the track bar.
trackRectangle.X = ClientRectangle.X + 2
trackRectangle.Y = ClientRectangle.Y + 28
trackRectangle.Width = ClientRectangle.Width - 4
trackRectangle.Height = 4
' Calculate the size of the rectangle in which to
' draw the ticks.
ticksRectangle.X = trackRectangle.X + 4
ticksRectangle.Y = trackRectangle.Y - 8
ticksRectangle.Width = trackRectangle.Width - 8
ticksRectangle.Height = 4
tickSpace = (CSng(ticksRectangle.Width) - 1) / _
(CSng(numberTicks) - 1)
' Calculate the size of the thumb.
thumbRectangle.Size = _
TrackBarRenderer.GetTopPointingThumbSize( _
g, TrackBarThumbState.Normal)
thumbRectangle.X = CurrentTickXCoordinate()
thumbRectangle.Y = trackRectangle.Y - 8
End Using
End Sub
Private Function CurrentTickXCoordinate() As Integer
If tickSpace = 0 Then
Return 0
Else
Return CInt(Math.Round(tickSpace)) * currentTickPosition
End If
End Function
' Draw the track bar.
Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
If Not TrackBarRenderer.IsSupported Then
Me.Parent.Text = "CustomTrackBar Disabled"
Return
End If
Me.Parent.Text = "CustomTrackBar Enabled"
TrackBarRenderer.DrawHorizontalTrack(e.Graphics, _
trackRectangle)
TrackBarRenderer.DrawTopPointingThumb(e.Graphics, _
thumbRectangle, thumbState)
TrackBarRenderer.DrawHorizontalTicks(e.Graphics, _
ticksRectangle, numberTicks, EdgeStyle.Raised)
End Sub
' Determine whether the user has clicked the track bar thumb.
Protected Overrides Sub OnMouseDown(ByVal e As MouseEventArgs)
If Not TrackBarRenderer.IsSupported Then
Return
End If
If Me.thumbRectangle.Contains(e.Location) Then
thumbClicked = True
thumbState = TrackBarThumbState.Pressed
End If
Me.Invalidate()
End Sub
' Redraw the track bar thumb if the user has moved it.
Protected Overrides Sub OnMouseUp(ByVal e As MouseEventArgs)
If Not TrackBarRenderer.IsSupported Then
Return
End If
If thumbClicked = True Then
If e.Location.X > trackRectangle.X And _
e.Location.X < trackRectangle.X + _
trackRectangle.Width - thumbRectangle.Width Then
thumbClicked = False
thumbState = TrackBarThumbState.Hot
Me.Invalidate()
End If
thumbClicked = False
End If
End Sub
' Track cursor movements.
Protected Overrides Sub OnMouseMove(ByVal e As MouseEventArgs)
If Not TrackBarRenderer.IsSupported Then
Return
End If
' The user is moving the thumb.
If thumbClicked = True Then
' Track movements to the next tick to the right, if the
' cursor has moved halfway to the next tick.
If currentTickPosition < numberTicks - 1 And _
e.Location.X > CurrentTickXCoordinate() + _
CInt(tickSpace) Then
currentTickPosition += 1
' Track movements to the next tick to the left, if
' the cursor has moved halfway to the next tick.
Else
If currentTickPosition > 0 And _
e.Location.X < CurrentTickXCoordinate() - _
CInt(tickSpace / 2) Then
currentTickPosition -= 1
End If
End If
thumbRectangle.X = CurrentTickXCoordinate()
' The cursor is passing over the track.
Else
If thumbRectangle.Contains(e.Location) Then
thumbState = TrackBarThumbState.Hot
Else
thumbState = TrackBarThumbState.Normal
End If
End If
Invalidate()
End Sub
End Class
End Namespace
備註
類別 TrackBarRenderer 提供一組 static 方法，可用來轉譯具有作業系統目前視覺化樣式之追蹤列控制項的每個部分。 呈現控制項是指繪製控制項的使用者介面。 如果您要繪製應該具有目前視覺化樣式外觀的自訂控制項，這會很有用。
如果在作業系統中啟用視覺化樣式，而視覺化樣式會套用至應用程式視窗的工作區，則此類別中的方法將會使用目前的視覺化樣式繪製追蹤列。 否則，這個類別中的方法會擲回 InvalidOperationException 。 若要判斷是否可以使用此類別的成員，您可以檢查 屬性的值 IsSupported 。
這個類別會將 System.Windows.Forms.VisualStyles.VisualStyleRenderer 的功能包裝為 類別所 System.Windows.Forms.VisualStyles.VisualStyleElement.TrackBar 公開的其中一個專案。 如需詳細資訊，請參閱 使用視覺化樣式轉譯控制項。
屬性
| IsSupported |
取得值，指出 TrackBarRenderer 類別是否可用來繪製具有視覺化樣式的追蹤列。 |