TrackBarRenderer Classe
Definição
Importante
Algumas informações se referem a produtos de pré-lançamento que podem ser substancialmente modificados antes do lançamento. A Microsoft não oferece garantias, expressas ou implícitas, das informações aqui fornecidas.
Fornece os métodos usados para renderizar um controle de barra de acompanhamento com estilos visuais. Essa classe não pode ser herdada.
public ref class TrackBarRenderer sealedpublic ref class TrackBarRenderer abstract sealedpublic sealed class TrackBarRendererpublic static class TrackBarRenderertype TrackBarRenderer = classPublic NotInheritable Class TrackBarRendererPublic Class TrackBarRenderer- Herança
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TrackBarRenderer
Exemplos
O exemplo de código a seguir demonstra como criar um controle personalizado que usa os TrackBarRenderer métodos para desenhar uma barra de faixa horizontal que responde a cliques do mouse.
#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
Comentários
A TrackBarRenderer classe fornece um conjunto de static métodos que podem ser usados para renderizar cada parte de um controle de barra de controle com o estilo visual atual do sistema operacional. Renderizar um controle refere-se a desenhar a interface do usuário de um controle. Isso será útil se você estiver desenhando um controle personalizado que deve ter a aparência do estilo visual atual.
Se os estilos visuais estiverem habilitados no sistema operacional e os estilos visuais forem aplicados à área do cliente das janelas do aplicativo, os métodos dessa classe desenharão a barra de faixa com o estilo visual atual. Caso contrário, os métodos nessa classe lançarão um InvalidOperationException. Para determinar se os membros dessa classe podem ser usados, você pode verificar o valor da IsSupported propriedade .
Essa classe encapsula a funcionalidade de um System.Windows.Forms.VisualStyles.VisualStyleRenderer que é definido como um dos elementos expostos pela System.Windows.Forms.VisualStyles.VisualStyleElement.TrackBar classe . Para obter mais informações, consulte Renderizando controles com estilos visuais.
Propriedades
| IsSupported |
Obtém um valor que indica se a classe TrackBarRenderer pode ser usada para desenhar uma barra de acompanhamento com estilos visuais. |
Métodos
| DrawBottomPointingThumb(Graphics, Rectangle, TrackBarThumbState) |
Desenha um controle deslizante da barra de acompanhamento que aponta para baixo (também conhecido como controle de posição) com estilos visuais. |
| DrawHorizontalThumb(Graphics, Rectangle, TrackBarThumbState) |
Desenha um controle deslizante da barra de acompanhamento horizontal (também conhecido como controle de posição) com estilos visuais. |
| DrawHorizontalTicks(Graphics, Rectangle, Int32, EdgeStyle) |
Desenha o número especificado de tiques de barra de acompanhamento horizontal com estilos visuais. |
| DrawHorizontalTrack(Graphics, Rectangle) |
Desenha a barra de uma barra de acompanhamento horizontal com estilos visuais. |
| DrawLeftPointingThumb(Graphics, Rectangle, TrackBarThumbState) |
Desenha um controle deslizante da barra de acompanhamento que aponta para a esquerda (também conhecido como controle de posição) com estilos visuais. |
| DrawRightPointingThumb(Graphics, Rectangle, TrackBarThumbState) |
Desenha um controle deslizante da barra de acompanhamento que aponta para a direita (também conhecido como controle de posição) com estilos visuais. |
| DrawTopPointingThumb(Graphics, Rectangle, TrackBarThumbState) |
Desenha um controle deslizante da barra de acompanhamento que aponta para cima (também conhecido como controle de posição) com estilos visuais. |
| DrawVerticalThumb(Graphics, Rectangle, TrackBarThumbState) |
Desenha um controle deslizante da barra de acompanhamento vertical (também conhecido como controle de posição) com estilos visuais. |
| DrawVerticalTicks(Graphics, Rectangle, Int32, EdgeStyle) |
Desenha o número especificado de tiques de barra de acompanhamento vertical com estilos visuais. |
| DrawVerticalTrack(Graphics, Rectangle) |
Desenha a barra de uma barra de acompanhamento vertical com estilos visuais. |
| GetBottomPointingThumbSize(Graphics, TrackBarThumbState) |
Retorna o tamanho, em pixels, do controle deslizante da barra de acompanhamento (também conhecido como controle de posição) que aponta para baixo. |
| GetLeftPointingThumbSize(Graphics, TrackBarThumbState) |
Retorna o tamanho, em pixels, do controle deslizante da barra de acompanhamento (também conhecido como controle de posição) que aponta para a esquerda. |
| GetRightPointingThumbSize(Graphics, TrackBarThumbState) |
Retorna o tamanho, em pixels, do controle deslizante da barra de acompanhamento (também conhecido como controle de posição) que aponta para a direita. |
| GetTopPointingThumbSize(Graphics, TrackBarThumbState) |
Retorna o tamanho, em pixels, do controle deslizante da barra de acompanhamento (também conhecido como controle de posição) que aponta para cima. |
Aplica-se a
Confira também
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