ToolStripProgressBar Classe

Definição

public ref class ToolStripProgressBar : System::Windows::Forms::ToolStripControlHost

public class ToolStripProgressBar : System.Windows.Forms.ToolStripControlHost

type ToolStripProgressBar = class
    inherit ToolStripControlHost

Public Class ToolStripProgressBar
Inherits ToolStripControlHost

Herança

Object

MarshalByRefObject

Component

ToolStripItem

ToolStripControlHost

ToolStripProgressBar

Exemplos

O exemplo de código seguinte demonstra um ToolStripProgressBar que calcula uma sequência de números de Fibonacci.

using System;
using System.ComponentModel;
using System.Windows.Forms;

class FibonacciNumber : Form
{
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.Run(new FibonacciNumber());
    }

    readonly StatusStrip progressStatusStrip;
    readonly ToolStripProgressBar toolStripProgressBar;
    readonly NumericUpDown requestedCountControl;
    readonly Button goButton;
    readonly TextBox outputTextBox;
    readonly BackgroundWorker backgroundWorker;
    readonly ToolStripStatusLabel toolStripStatusLabel;
    int requestedCount;

    public FibonacciNumber()
    {
        Text = "Fibonacci";

        // Prepare the StatusStrip.
        progressStatusStrip = new StatusStrip();
        toolStripProgressBar = new ToolStripProgressBar
        {
            Enabled = false
        };
        toolStripStatusLabel = new ToolStripStatusLabel();
        _ = progressStatusStrip.Items.Add(toolStripProgressBar);
        _ = progressStatusStrip.Items.Add(toolStripStatusLabel);

        FlowLayoutPanel flp = new()
        {
            Dock = DockStyle.Top
        };

        Label beforeLabel = new()
        {
            Text = "Calculate the first ",
            AutoSize = true
        };
        flp.Controls.Add(beforeLabel);
        requestedCountControl = new NumericUpDown
        {
            Maximum = 1000,
            Minimum = 1,
            Value = 100
        };
        flp.Controls.Add(requestedCountControl);
        Label afterLabel = new()
        {
            Text = "Numbers in the Fibonacci sequence.",
            AutoSize = true
        };
        flp.Controls.Add(afterLabel);

        goButton = new Button
        {
            Text = "&Go"
        };
        goButton.Click += button1_Click;
        flp.Controls.Add(goButton);

        outputTextBox = new TextBox
        {
            Multiline = true,
            ReadOnly = true,
            ScrollBars = ScrollBars.Vertical,
            Dock = DockStyle.Fill
        };

        Controls.Add(outputTextBox);
        Controls.Add(progressStatusStrip);
        Controls.Add(flp);

        backgroundWorker = new BackgroundWorker
        {
            WorkerReportsProgress = true
        };
        backgroundWorker.DoWork += backgroundWorker1_DoWork;
        backgroundWorker.RunWorkerCompleted += backgroundWorker1_RunWorkerCompleted;
        backgroundWorker.ProgressChanged += backgroundWorker1_ProgressChanged;
    }

    void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
    {
        // This method will run on a thread other than the UI thread.
        // Be sure not to manipulate any Windows Forms controls created
        // on the UI thread from this method.
        backgroundWorker.ReportProgress(0, "Working...");
        decimal lastlast = 0;
        decimal last = 1;
        decimal current;
        if (requestedCount >= 1)
        { AppendNumber(0); }
        if (requestedCount >= 2)
        { AppendNumber(1); }
        for (int i = 2; i < requestedCount; ++i)
        {
            // Calculate the number.
            checked { current = lastlast + last; }
            // Introduce some delay to simulate a more complicated calculation.
            System.Threading.Thread.Sleep(100);
            AppendNumber(current);
            backgroundWorker.ReportProgress(100 * i / requestedCount, "Working...");
            // Get ready for the next iteration.
            lastlast = last;
            last = current;
        }

        backgroundWorker.ReportProgress(100, "Complete!");
    }

    delegate void AppendNumberDelegate(decimal number);
    void AppendNumber(decimal number)
    {
        if (outputTextBox.InvokeRequired)
        { _ = outputTextBox.Invoke(new AppendNumberDelegate(AppendNumber), number); }
        else
        { outputTextBox.AppendText(number.ToString("N0") + Environment.NewLine); }
    }
    void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        toolStripProgressBar.Value = e.ProgressPercentage;
        toolStripStatusLabel.Text = e.UserState as string;
    }

    void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        if (e.Error is OverflowException)
        { outputTextBox.AppendText(Environment.NewLine + "**OVERFLOW ERROR, number is too large to be represented by the decimal data type**"); }
        toolStripProgressBar.Enabled = false;
        requestedCountControl.Enabled = true;
        goButton.Enabled = true;
    }

    void button1_Click(object sender, EventArgs e)
    {
        goButton.Enabled = false;
        toolStripProgressBar.Enabled = true;
        requestedCount = (int)requestedCountControl.Value;
        requestedCountControl.Enabled = false;
        outputTextBox.Clear();
        backgroundWorker.RunWorkerAsync();
    }
}

Imports System.Collections.Generic
Imports System.Windows.Forms
Imports System.ComponentModel



Class FibonacciNumber
   Inherits Form
   
   <STAThread()>  _
   Shared Sub Main()
      Application.EnableVisualStyles()
      Application.Run(New FibonacciNumber())
   End Sub    
   Private progressStatusStrip As StatusStrip
   Private toolStripProgressBar As ToolStripProgressBar
   Private requestedCountControl As NumericUpDown
   Private goButton As Button
   Private outputTextBox As TextBox
   Private backgroundWorker As BackgroundWorker
   Private toolStripStatusLabel As ToolStripStatusLabel
   Private requestedCount As Integer
   
   
   Public Sub New()
      [Text] = "Fibonacci"
      
      ' Prepare the StatusStrip.
      progressStatusStrip = New StatusStrip()
      toolStripProgressBar = New ToolStripProgressBar()
      toolStripProgressBar.Enabled = False
      toolStripStatusLabel = New ToolStripStatusLabel()
      progressStatusStrip.Items.Add(toolStripProgressBar)
      progressStatusStrip.Items.Add(toolStripStatusLabel)
      
      Dim flp As New FlowLayoutPanel()
      flp.Dock = DockStyle.Top
      
      Dim beforeLabel As New Label()
      beforeLabel.Text = "Calculate the first "
      beforeLabel.AutoSize = True
      flp.Controls.Add(beforeLabel)
      requestedCountControl = New NumericUpDown()
      requestedCountControl.Maximum = 1000
      requestedCountControl.Minimum = 1
      requestedCountControl.Value = 100
      flp.Controls.Add(requestedCountControl)
      Dim afterLabel As New Label()
      afterLabel.Text = "Numbers in the Fibonacci sequence."
      afterLabel.AutoSize = True
      flp.Controls.Add(afterLabel)
      
      goButton = New Button()
      goButton.Text = "&Go"
      AddHandler goButton.Click, AddressOf button1_Click
      flp.Controls.Add(goButton)
      
      outputTextBox = New TextBox()
      outputTextBox.Multiline = True
      outputTextBox.ReadOnly = True
      outputTextBox.ScrollBars = ScrollBars.Vertical
      outputTextBox.Dock = DockStyle.Fill
      
      Controls.Add(outputTextBox)
      Controls.Add(progressStatusStrip)
      Controls.Add(flp)
      
      backgroundWorker = New BackgroundWorker()
      backgroundWorker.WorkerReportsProgress = True
      AddHandler backgroundWorker.DoWork, AddressOf backgroundWorker1_DoWork
      AddHandler backgroundWorker.RunWorkerCompleted, AddressOf backgroundWorker1_RunWorkerCompleted
      AddHandler backgroundWorker.ProgressChanged, AddressOf backgroundWorker1_ProgressChanged
   End Sub 
    
   
   Private Sub backgroundWorker1_DoWork(sender As Object, e As DoWorkEventArgs)
      ' This method will run on a thread other than the UI thread.
      ' Be sure not to manipulate any Windows Forms controls created
      ' on the UI thread from this method.
      backgroundWorker.ReportProgress(0, "Working...")
      Dim lastlast As [Decimal] = 0
      Dim last As [Decimal] = 1
      Dim current As [Decimal]
      If requestedCount >= 1 Then
         AppendNumber(0)
      End If
      If requestedCount >= 2 Then
         AppendNumber(1)
      End If
      Dim i As Integer
      
      While i < requestedCount
         ' Calculate the number.
         current = lastlast + last
         ' Introduce some delay to simulate a more complicated calculation.
         System.Threading.Thread.Sleep(100)
         AppendNumber(current)
         backgroundWorker.ReportProgress(100 * i / requestedCount, "Working...")
         ' Get ready for the next iteration.
         lastlast = last
         last = current
         i += 1
      End While
      
      
      backgroundWorker.ReportProgress(100, "Complete!")
    End Sub
   
   
   Delegate Sub AppendNumberDelegate(number As [Decimal])
   
   Private Sub AppendNumber(number As [Decimal])
      If outputTextBox.InvokeRequired Then
         outputTextBox.Invoke(New AppendNumberDelegate(AddressOf AppendNumber), number)
      Else
         outputTextBox.AppendText((number.ToString("N0") + Environment.NewLine))
      End If
   End Sub 
   Private Sub backgroundWorker1_ProgressChanged(sender As Object, e As ProgressChangedEventArgs)
      toolStripProgressBar.Value = e.ProgressPercentage
      toolStripStatusLabel.Text = e.UserState '
   End Sub 
   
   
   Private Sub backgroundWorker1_RunWorkerCompleted(sender As Object, e As RunWorkerCompletedEventArgs)
      If TypeOf e.Error Is OverflowException Then
         outputTextBox.AppendText((Environment.NewLine + "**OVERFLOW ERROR, number is too large to be represented by the decimal data type**"))
      End If
      toolStripProgressBar.Enabled = False
      requestedCountControl.Enabled = True
      goButton.Enabled = True
   End Sub 
    
   
   Private Sub button1_Click(sender As Object, e As EventArgs)
      goButton.Enabled = False
      toolStripProgressBar.Enabled = True
      requestedCount = Fix(requestedCountControl.Value)
      requestedCountControl.Enabled = False
      outputTextBox.Clear()
      backgroundWorker.RunWorkerAsync()
   End Sub 
End Class

Observações

ToolStripProgressBar é o ProgressBar otimizado para alojamento num ToolStrip. Um subconjunto das propriedades e eventos do controlo hospedado é exposto ao nível ToolStripProgressBar, mas o controlo subjacente ProgressBar é totalmente acessível pela propriedade ProgressBar.

Um controlo ToolStripProgressBar indica visualmente o progresso de uma operação longa. O ToolStripProgressBar controlo apresenta uma barra que preenche da esquerda para a direita com a cor de destaque do sistema à medida que a operação avança.

O ToolStripProgressBar controlo é normalmente utilizado quando uma aplicação realiza tarefas como copiar ficheiros ou imprimir documentos. Os utilizadores de uma aplicação podem considerar que esta não responde se não houver sinal visual. Use o ToolStripProgressBar para notificar o utilizador de que a aplicação está a realizar uma tarefa longa e que a aplicação continua a responder.

As Maximum propriedades e Minimum definem o intervalo de valores para representar o progresso de uma tarefa. A Minimum propriedade é normalmente definida com um valor zero, e a Maximum propriedade é normalmente definida para um valor que indica a conclusão de uma tarefa. Por exemplo, para mostrar corretamente o progresso ao copiar um grupo de ficheiros, a Maximum propriedade podia ser definida para o número total de ficheiros a copiar. A Value propriedade representa o progresso que a candidatura fez na conclusão da operação. Como a barra exibida no controlo é uma coleção de blocos, o valor apresentado ToolStripProgressBar apenas aproxima o Value valor atual da propriedade. Com base no tamanho do ToolStripProgressBar, a Value propriedade determina quando mostrar o próximo bloco.

Existem várias formas de modificar o valor apresentado ToolStripProgressBar pelo outro para além de alterar diretamente a Value propriedade. Pode usar a Step propriedade para especificar um valor específico para incrementar a Value propriedade e depois chamar o PerformStep método para incrementar o valor. Para variar o valor de incremento, pode usar o Increment método e especificar um valor pelo qual incrementar a Value propriedade.

ToolStripProgressBar substitui o controlo antigo ProgressBar , que ainda assim é mantido para compatibilidade retroativa.

Ver também

• ToolStrip (Windows Forms)