ProgressBarRenderer Classe

Definizione

Spazio dei nomi:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Fornisce i metodi utilizzati per eseguire il rendering di un controllo indicatore di stato con gli stili di visualizzazione. La classe non può essere ereditata.

public ref class ProgressBarRenderer abstract sealed

public static class ProgressBarRenderer

type ProgressBarRenderer = class

Public Class ProgressBarRenderer

Ereditarietà

Object

ProgressBarRenderer

Esempio

Nell'esempio di codice seguente viene illustrato come creare un controllo personalizzato che usa i DrawVerticalBar metodi e DrawVerticalChunks per disegnare una barra di stato verticale. Il controllo usa un Timer oggetto per ridisegnare la barra di avanzamento con un pezzo aggiunto ogni secondo. Il SetupProgressBar metodo usa le ChunkThickness proprietà e ChunkSpaceThickness per calcolare l'altezza di ogni rettangolo progressivamente più grande disegnato.

#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 ProgressBarRendererSample
{
    public ref class VerticalProgressBar : public Control
    {
    private:
        int numberChunksValue;
        int ticks;
        Timer^ progressTimer;
        array<Rectangle>^ progressBarRectangles;

    public:
        VerticalProgressBar() : Control()
        {
            this->Location = Point(10, 10);
            this->Width = 50;
            progressTimer = gcnew Timer();

            // The progress bar will update every second.
            progressTimer->Interval = 1000;
            progressTimer->Tick += gcnew EventHandler(this,
                &VerticalProgressBar::progressTimer_Tick);

            // This property also calls SetupProgressBar to initialize
            // the progress bar rectangles if styles are enabled.
            NumberChunks = 20;

            // Set the default height if visual styles are not enabled.
            if (!ProgressBarRenderer::IsSupported)
            {
                this->Height = 100;
            }
        }

        // Specify the number of progress bar chunks to base the height on.
    public:
        property int NumberChunks
        {
            int get()
            {
                return numberChunksValue;
            }

            void set(int value)
            {
                if (value <= 50 && value > 0)
                {
                    numberChunksValue = value;
                }
                else
                {
                    MessageBox::Show("Number of chunks must be between " +
                        "0 and 50; defaulting to 10");
                    numberChunksValue = 10;
                }

                // Recalculate the progress bar size, if visual styles
                // are active.
                if (ProgressBarRenderer::IsSupported)
                {
                    SetupProgressBar();
                }
            }
        }

        // Draw the progress bar in its normal state.
    protected:
        virtual void OnPaint(PaintEventArgs^ e) override
        {
            __super::OnPaint(e);

            if (ProgressBarRenderer::IsSupported)
            {
                ProgressBarRenderer::DrawVerticalBar(e->Graphics, 
                    ClientRectangle);
                this->Parent->Text = "VerticalProgressBar Enabled";
            }
            else
            {
                this->Parent->Text = "VerticalProgressBar Disabled";
            }
        }

        // Initialize the rectangles used to paint the states of the
        // progress bar.
    private:
        void SetupProgressBar()
        {
            if (!ProgressBarRenderer::IsSupported)
            {
                return;
            }

            // Determine the size of the progress bar frame.
            this->Size = System::Drawing::Size(ClientRectangle.Width,
                (NumberChunks * (ProgressBarRenderer::ChunkThickness + 
                (2 * ProgressBarRenderer::ChunkSpaceThickness))) + 6);

            // Initialize the rectangles to draw each step of the
            // progress bar.
            progressBarRectangles = gcnew array<Rectangle>(NumberChunks);

            for (int i = 0; i < NumberChunks; i++)
            {
                // Use the thickness defined by the current visual style
                // to calculate the height of each rectangle. The size
                // adjustments ensure that the chunks do not paint over
                // the frame.

                int filledRectangleHeight = 
                    ((i + 1) * (ProgressBarRenderer::ChunkThickness +
                    (2 * ProgressBarRenderer::ChunkSpaceThickness)));

                progressBarRectangles[i] = Rectangle(
                    ClientRectangle.X + 3,
                    ClientRectangle.Y + ClientRectangle.Height - 3
                    - filledRectangleHeight,
                    ClientRectangle.Width - 6,
                    filledRectangleHeight);
            }
        }

        // Handle the timer tick; draw each progressively larger rectangle.
    private:
        void progressTimer_Tick(Object^ myObject, EventArgs^ e)
        {
            if (ticks < NumberChunks)
            {
                Graphics^ g = this->CreateGraphics();
                ProgressBarRenderer::DrawVerticalChunks(g,
                    progressBarRectangles[ticks]);
                ticks++;
            }
            else
            {
                progressTimer->Enabled = false;
            }
        }

        // Start the progress bar.
    public:
        void Start()
        {
            if (ProgressBarRenderer::IsSupported)
            {
                progressTimer->Start();
            }
            else
            {
                MessageBox::Show("VerticalScrollBar requires visual styles");
            }
        }
    };

    public ref class Form1 : public Form
    {
    private:
        VerticalProgressBar^ bar1;
        Button^ button1;

    public:
        Form1() : Form()
        {
            this->Size = System::Drawing::Size(500, 500);
            bar1 = gcnew VerticalProgressBar();
            bar1->NumberChunks = 30;
            button1 = gcnew Button();
            button1->Location = Point(150, 10);
            button1->Size = System::Drawing::Size(150, 30);
            button1->Text = "Start VerticalProgressBar";
            button1->Click += gcnew EventHandler(this, &Form1::button1_Click);
            Controls->AddRange(gcnew array<Control^> { button1, bar1 });
        }

        // Start the VerticalProgressBar.
    private:
        void button1_Click(Object^ sender, EventArgs^ e)
        {
            bar1->Start();
        }
    };
}


[STAThread]
int main()
{
    // The call to EnableVisualStyles below does not affect
    // whether ProgressBarRenderer.IsSupported is true; as
    // long as visual styles are enabled by the operating system,
    // IsSupported is true.
    Application::EnableVisualStyles();
    Application::Run(gcnew ProgressBarRendererSample::Form1());
}

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;

namespace ProgressBarRendererSample
{
    public class Form1 : Form
    {
        private VerticalProgressBar bar1 = new VerticalProgressBar();
        private Button button1 = new Button();

        public Form1()
            : base()
        {
            this.Size = new Size(500, 500);
            bar1.NumberChunks = 30;
            button1.Location = new Point(150, 10);
            button1.Size = new Size(150, 30);
            button1.Text = "Start VerticalProgressBar";
            button1.Click += new EventHandler(button1_Click);
            Controls.AddRange(new Control[] { button1, bar1 });
        }

        [STAThread]
        public static void Main()
        {
            // The call to EnableVisualStyles below does not affect
            // whether ProgressBarRenderer.IsSupported is true; as 
            // long as visual styles are enabled by the operating system, 
            // IsSupported is true.
            Application.EnableVisualStyles();
            Application.Run(new Form1());
        }

        // Start the VerticalProgressBar.
        private void button1_Click(object sender, EventArgs e)
        {
            bar1.Start();
        }
    }

    public class VerticalProgressBar : Control
    {
        private int numberChunksValue;
        private int ticks;
        private Timer progressTimer = new Timer();
        private Rectangle[] progressBarRectangles;

        public VerticalProgressBar()
            : base()
        {
            this.Location = new Point(10, 10);
            this.Width = 50;

            // The progress bar will update every second.
            progressTimer.Interval = 1000;
            progressTimer.Tick += new EventHandler(progressTimer_Tick);

            // This property also calls SetupProgressBar to initialize 
            // the progress bar rectangles if styles are enabled.
            NumberChunks = 20;

            // Set the default height if visual styles are not enabled.
            if (!ProgressBarRenderer.IsSupported)
            {
                this.Height = 100;
            }
        }

        // Specify the number of progress bar chunks to base the height on.
        public int NumberChunks
        {
            get
            {
                return numberChunksValue;
            }

            set
            {
                if (value <= 50 && value > 0)
                {
                    numberChunksValue = value;
                }
                else
                {
                    MessageBox.Show("Number of chunks must be between " +
                        "0 and 50; defaulting to 10");
                    numberChunksValue = 10;
                }

                // Recalculate the progress bar size, if visual styles 
                // are active.
                if (ProgressBarRenderer.IsSupported)
                {
                    SetupProgressBar();
                }
            }
        }

        // Draw the progress bar in its normal state.
        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);

            if (ProgressBarRenderer.IsSupported)
            {
                ProgressBarRenderer.DrawVerticalBar(e.Graphics,
                    ClientRectangle);
                this.Parent.Text = "VerticalProgressBar Enabled";
            }
            else
            {
                this.Parent.Text = "VerticalProgressBar Disabled";
            }
        }

        // Initialize the rectangles used to paint the states of the 
        // progress bar.
        private void SetupProgressBar()
        {
            if (!ProgressBarRenderer.IsSupported)
            {
                return;
            }

            // Determine the size of the progress bar frame.
            this.Size = new Size(ClientRectangle.Width,
                (NumberChunks) * (ProgressBarRenderer.ChunkThickness +
                (2 * ProgressBarRenderer.ChunkSpaceThickness)) + 6);

            // Initialize the rectangles to draw each step of the 
            // progress bar.
            progressBarRectangles = new Rectangle[NumberChunks];

            for (int i = 0; i < NumberChunks; i++)
            {
                // Use the thickness defined by the current visual style 
                // to calculate the height of each rectangle. The size 
                // adjustments ensure that the chunks do not paint over 
                // the frame.

                int filledRectangleHeight =
                    ((i + 1) * (ProgressBarRenderer.ChunkThickness +
                    (2 * ProgressBarRenderer.ChunkSpaceThickness)));

                progressBarRectangles[i] = new Rectangle(
                    ClientRectangle.X + 3,
                    ClientRectangle.Y + ClientRectangle.Height - 3
                    - filledRectangleHeight,
                    ClientRectangle.Width - 6,
                    filledRectangleHeight);
            }
        }

        // Handle the timer tick; draw each progressively larger rectangle.
        private void progressTimer_Tick(Object myObject, EventArgs e)
        {
            if (ticks < NumberChunks)
            {
                using (Graphics g = this.CreateGraphics())
                {
                    ProgressBarRenderer.DrawVerticalChunks(g,
                        progressBarRectangles[ticks]);
                    ticks++;
                }
            }
            else
            {
                progressTimer.Enabled = false;
            }
        }

        // Start the progress bar.
        public void Start()
        {
            if (ProgressBarRenderer.IsSupported)
            {
                progressTimer.Start();
            }
            else
            {
                MessageBox.Show("VerticalScrollBar requires visual styles");
            }
        }
    }
}

Imports System.Drawing
Imports System.Windows.Forms
Imports System.Windows.Forms.VisualStyles



Public Class Form1
    Inherits Form
    Private bar1 As New VerticalProgressBar()
    Private button1 As New Button()
    
    
    Public Sub New() 
        Me.Size = New Size(500, 500)
        bar1.NumberChunks = 30
        button1.Location = New Point(150, 10)
        button1.Size = New Size(150, 30)
        button1.Text = "Start VerticalProgressBar"
        AddHandler button1.Click, AddressOf button1_Click
        Controls.AddRange(New Control() {button1, bar1})
    
    End Sub
    
    
    <STAThread()>  _
    Public Shared Sub Main() 
        ' The call to EnableVisualStyles below does not affect
        ' whether ProgressBarRenderer.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
    
    
    ' Start the VerticalProgressBar.
    Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) 
        bar1.Start()
    
    End Sub
End Class


Public Class VerticalProgressBar
    Inherits Control
    Private numberChunksValue As Integer
    Private ticks As Integer
    Private progressTimer As New Timer()
    Private progressBarRectangles() As Rectangle
    
    
    Public Sub New() 
        Me.Location = New Point(10, 10)
        Me.Width = 50
        
        ' The progress bar will update every second.
        progressTimer.Interval = 1000
        AddHandler progressTimer.Tick, AddressOf progressTimer_Tick
        
        ' This property also calls SetupProgressBar to initialize 
        ' the progress bar rectangles if styles are enabled.
        NumberChunks = 20
        
        ' Set the default height if visual styles are not enabled.
        If Not ProgressBarRenderer.IsSupported Then
            Me.Height = 100
        End If
    
    End Sub
    
    ' Specify the number of progress bar chunks to base the height on.
    
    Public Property NumberChunks() As Integer 
        Get
            Return numberChunksValue
        End Get
        
        Set
            If value <= 50 AndAlso value > 0 Then
                numberChunksValue = value
            Else
                MessageBox.Show("Number of chunks must be between " + "0 and 50; defaulting to 10")
                numberChunksValue = 10
            End If
            
            ' Recalculate the progress bar size, if visual styles 
            ' are active.
            If ProgressBarRenderer.IsSupported Then
                SetupProgressBar()
            End If
        End Set
    End Property
    
    
    ' Draw the progress bar in its normal state.
    Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs) 
        MyBase.OnPaint(e)
        
        If ProgressBarRenderer.IsSupported Then
            ProgressBarRenderer.DrawVerticalBar(e.Graphics, ClientRectangle)
            Me.Parent.Text = "VerticalProgressBar Enabled"
        Else
            Me.Parent.Text = "VerticalProgressBar Disabled"
        End If
    
    End Sub
    
    ' Initialize the rectangles used to paint the states of the 
    ' progress bar.
    Private Sub SetupProgressBar() 
        If Not ProgressBarRenderer.IsSupported Then
            Return
        End If
        
        ' Determine the size of the progress bar frame.
        Me.Size = New Size(ClientRectangle.Width, NumberChunks *(ProgressBarRenderer.ChunkThickness + 2 * ProgressBarRenderer.ChunkSpaceThickness) + 6)
        
        ' Initialize the rectangles to draw each step of the 
        ' progress bar.
        progressBarRectangles = New Rectangle(NumberChunks) {}
        
        Dim i As Integer
        For i = 0 To NumberChunks
            ' Use the thickness defined by the current visual style 
            ' to calculate the height of each rectangle. The size 
            ' adjustments ensure that the chunks do not paint over 
            ' the frame.
            Dim filledRectangleHeight As Integer = (i + 1)  _
        *(ProgressBarRenderer.ChunkThickness + 2 * ProgressBarRenderer.ChunkSpaceThickness)
            
            progressBarRectangles(i) = New Rectangle(ClientRectangle.X + 3, _
                ClientRectangle.Y + ClientRectangle.Height - 3 - filledRectangleHeight, _
                ClientRectangle.Width - 6, filledRectangleHeight)
        Next i
    
    End Sub
    
    ' Handle the timer tick; draw each progressively larger rectangle.
    Private Sub progressTimer_Tick(ByVal myObject As [Object], ByVal e As EventArgs) 
        If ticks < NumberChunks Then
            Dim g As Graphics = Me.CreateGraphics()
            Try
                ProgressBarRenderer.DrawVerticalChunks(g, progressBarRectangles(ticks))
                ticks += 1
            Finally
                g.Dispose()
            End Try
        Else
            progressTimer.Enabled = False
        End If
    
    End Sub
    
    ' Start the progress bar.
    Public Sub Start() 
        If ProgressBarRenderer.IsSupported Then
            progressTimer.Start()
        Else
            MessageBox.Show("VerticalScrollBar requires visual styles")
        End If
    
    End Sub
End Class

Commenti

La ProgressBarRenderer classe fornisce un set di metodi che possono essere usati per eseguire il rendering di un controllo barra di static stato con lo stile visivo corrente del sistema operativo. Il rendering di un controllo si riferisce alla grafica dell'interfaccia utente di un controllo. Questo è utile se si disegna un controllo personalizzato che deve avere l'aspetto dello stile di visualizzazione corrente. Per disegnare una barra di stato, usare i DrawHorizontalBar metodi o DrawVerticalBar per disegnare la barra vuota e quindi usare i DrawHorizontalChunks metodi o DrawVerticalChunks per disegnare gli elementi che riempiono la barra.

Se gli stili di visualizzazione sono abilitati nel sistema operativo e gli stili visivi vengono applicati all'area client delle finestre dell'applicazione, i metodi di questa classe disegnano la barra di avanzamento con lo stile di visualizzazione corrente. In caso contrario, i metodi e le proprietà di questa classe genereranno un InvalidOperationExceptionoggetto . Per determinare se è possibile usare i membri di questa classe, è possibile controllare il valore della IsSupported proprietà.

Questa classe esegue il wrapping della funzionalità di un System.Windows.Forms.VisualStyles.VisualStyleRenderer oggetto impostato su uno degli elementi esposti dalle System.Windows.Forms.VisualStyles.VisualStyleElement.ProgressBar.Barclassi , System.Windows.Forms.VisualStyles.VisualStyleElement.ProgressBar.BarVertical, System.Windows.Forms.VisualStyles.VisualStyleElement.ProgressBar.Chunke System.Windows.Forms.VisualStyles.VisualStyleElement.ProgressBar.ChunkVertical . Per altre informazioni, vedere Controlli di rendering con stili di visualizzazione.

Proprietà

ChunkSpaceThickness	Ottiene la larghezza, in pixel, dello spazio tra ciascuna porzione interna dell'indicatore di stato.
ChunkThickness	Ottiene la larghezza, in pixel, di una singola porzione interna dell'indicatore di stato.
IsSupported	Ottiene un valore che indica se la classe ProgressBarRenderer può essere utilizzata per disegnare un indicatore di stato con gli stili di visualizzazione.

Metodi

DrawHorizontalBar(Graphics, Rectangle)	Disegna un controllo indicatore di stato vuoto che viene riempito orizzontalmente.
DrawHorizontalChunks(Graphics, Rectangle)	Disegna un insieme di porzioni che riempiono un indicatore di stato orizzontale.
DrawVerticalBar(Graphics, Rectangle)	Disegna un controllo indicatore di stato vuoto che viene riempito verticalmente.
DrawVerticalChunks(Graphics, Rectangle)	Disegna un insieme di porzioni che riempiono un indicatore di stato verticale.

Vedi anche

• VisualStyleRenderer
• VisualStyleElement