TrackBarRenderer 類別

  • 參考

定義

命名空間:
System.Windows.Forms
組件:
System.Windows.Forms.dll

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 sealed
public ref class TrackBarRenderer abstract sealed
public sealed class TrackBarRenderer
public static class TrackBarRenderer
type TrackBarRenderer = class
Public NotInheritable Class TrackBarRenderer
Public Class TrackBarRenderer
繼承
Object
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。

方法

DrawBottomPointingThumb(Graphics, Rectangle, TrackBarThumbState)

繪製具有視覺化樣式的下指 (Downward-Pointing) 追蹤列滑桿 (也稱為捲動方塊)。
DrawHorizontalThumb(Graphics, Rectangle, TrackBarThumbState)

繪製具有視覺化樣式的水平追蹤列滑桿 (也稱為捲動方塊)。
DrawHorizontalTicks(Graphics, Rectangle, Int32, EdgeStyle)

繪製具有視覺化樣式之指定數目的水平追蹤列刻度。
DrawHorizontalTrack(Graphics, Rectangle)

繪製具有視覺化樣式之水平追蹤列的追蹤。
DrawLeftPointingThumb(Graphics, Rectangle, TrackBarThumbState)

繪製具有視覺化樣式的左指 (Left-Pointing) 追蹤列滑桿 (也稱為捲動方塊)。
DrawRightPointingThumb(Graphics, Rectangle, TrackBarThumbState)

繪製具有視覺化樣式的右指 (Right-Pointing) 追蹤列滑桿 (也稱為捲動方塊)。
DrawTopPointingThumb(Graphics, Rectangle, TrackBarThumbState)

繪製具有視覺化樣式的上指 (Upward-Pointing) 追蹤列滑桿 (也稱為捲動方塊)。
DrawVerticalThumb(Graphics, Rectangle, TrackBarThumbState)

繪製具有視覺化樣式的垂直追蹤列滑桿 (也稱為捲動方塊)。
DrawVerticalTicks(Graphics, Rectangle, Int32, EdgeStyle)

繪製具有視覺化樣式之指定數目的垂直追蹤列刻度。
DrawVerticalTrack(Graphics, Rectangle)

繪製具有視覺化樣式之垂直追蹤列的追蹤。
GetBottomPointingThumbSize(Graphics, TrackBarThumbState)

傳回指向下方之追蹤列滑桿 (也稱為捲動方塊) 的大小 (以像素為單位)。
GetLeftPointingThumbSize(Graphics, TrackBarThumbState)

傳回指向左方之追蹤列滑桿 (也稱為捲動方塊) 的大小 (以像素為單位)。
GetRightPointingThumbSize(Graphics, TrackBarThumbState)

傳回指向右方之追蹤列滑桿 (也稱為捲動方塊) 的大小 (以像素為單位)。
GetTopPointingThumbSize(Graphics, TrackBarThumbState)

傳回指向上方之追蹤列滑桿 (也稱為捲動方塊) 的大小 (以像素為單位)。

適用於

另請參閱