BackgroundWorker BackgroundWorker BackgroundWorker BackgroundWorker Class

정의

별도의 스레드에서 작업을 실행합니다.Executes an operation on a separate thread.

public ref class BackgroundWorker : System::ComponentModel::Component
public class BackgroundWorker : System.ComponentModel.Component
type BackgroundWorker = class
    inherit Component
Public Class BackgroundWorker
Inherits Component
상속

예제

다음 코드 예제는 기본 사항을 보여줍니다는 BackgroundWorker 시간이 많이 걸리는 작업을 비동기적으로 실행 하기 위한 클래스입니다.The following code example demonstrates the basics of the BackgroundWorker class for executing a time-consuming operation asynchronously. 다음 그림에서는 출력의 예를 보여 줍니다.The following illustration shows an example of the output.

BackgroundWorker 간단한 예제BackgroundWorker simple example

이 코드를 실행 하려면 Windows Forms 애플리케이션을 작성 합니다.To try this code, create a Windows Forms application. 추가 Label 라는 컨트롤 resultLabel 두 개의 추가 Button 컨트롤 이라는 startAsyncButtoncancelAsyncButton합니다.Add a Label control named resultLabel and add two Button controls named startAsyncButton and cancelAsyncButton. 만들 Click 두 단추에 대 한 이벤트 처리기입니다.Create Click event handlers for both buttons. 구성 요소 탭 도구 상자의 추가 BackgroundWorker 라는 구성 요소 backgroundWorker1합니다.From the Components tab of the Toolbox, add a BackgroundWorker component named backgroundWorker1. 만들 DoWork, ProgressChanged, 및 RunWorkerCompleted 에 대 한 이벤트 처리기는 BackgroundWorker합니다.Create DoWork, ProgressChanged, and RunWorkerCompleted event handlers for the BackgroundWorker. 폼의 코드에서 기존 코드를 다음 코드로 바꿉니다.In the code for the form, replace the existing code with the following code.

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

namespace BackgroundWorkerSimple
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            backgroundWorker1.WorkerReportsProgress = true;
            backgroundWorker1.WorkerSupportsCancellation = true;
        }

        private void startAsyncButton_Click(object sender, EventArgs e)
        {
            if (backgroundWorker1.IsBusy != true)
            {
                // Start the asynchronous operation.
                backgroundWorker1.RunWorkerAsync();
            }
        }

        private void cancelAsyncButton_Click(object sender, EventArgs e)
        {
            if (backgroundWorker1.WorkerSupportsCancellation == true)
            {
                // Cancel the asynchronous operation.
                backgroundWorker1.CancelAsync();
            }
        }

        // This event handler is where the time-consuming work is done.
        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            BackgroundWorker worker = sender as BackgroundWorker;

            for (int i = 1; i <= 10; i++)
            {
                if (worker.CancellationPending == true)
                {
                    e.Cancel = true;
                    break;
                }
                else
                {
                    // Perform a time consuming operation and report progress.
                    System.Threading.Thread.Sleep(500);
                    worker.ReportProgress(i * 10);
                }
            }
        }

        // This event handler updates the progress.
        private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            resultLabel.Text = (e.ProgressPercentage.ToString() + "%");
        }

        // This event handler deals with the results of the background operation.
        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if (e.Cancelled == true)
            {
                resultLabel.Text = "Canceled!";
            }
            else if (e.Error != null)
            {
                resultLabel.Text = "Error: " + e.Error.Message;
            }
            else
            {
                resultLabel.Text = "Done!";
            }
        }
    }
}
Imports System.ComponentModel

Public Class Form1

    Public Sub New()
        InitializeComponent()
        backgroundWorker1.WorkerReportsProgress = True
        backgroundWorker1.WorkerSupportsCancellation = True
    End Sub

    Private Sub startAsyncButton_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles startAsyncButton.Click
        If backgroundWorker1.IsBusy <> True Then
            ' Start the asynchronous operation.
            backgroundWorker1.RunWorkerAsync()
        End If
    End Sub

    Private Sub cancelAsyncButton_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles cancelAsyncButton.Click
        If backgroundWorker1.WorkerSupportsCancellation = True Then
            ' Cancel the asynchronous operation.
            backgroundWorker1.CancelAsync()
        End If
    End Sub

    ' This event handler is where the time-consuming work is done.
    Private Sub backgroundWorker1_DoWork(ByVal sender As System.Object, _
    ByVal e As DoWorkEventArgs) Handles backgroundWorker1.DoWork
        Dim worker As BackgroundWorker = CType(sender, BackgroundWorker)
        Dim i As Integer

        For i = 1 To 10
            If (worker.CancellationPending = True) Then
                e.Cancel = True
                Exit For
            Else
                ' Perform a time consuming operation and report progress.
                System.Threading.Thread.Sleep(500)
                worker.ReportProgress(i * 10)
            End If
        Next
    End Sub

    ' This event handler updates the progress.
    Private Sub backgroundWorker1_ProgressChanged(ByVal sender As System.Object, _
    ByVal e As ProgressChangedEventArgs) Handles backgroundWorker1.ProgressChanged
        resultLabel.Text = (e.ProgressPercentage.ToString() + "%")
    End Sub

    ' This event handler deals with the results of the background operation.
    Private Sub backgroundWorker1_RunWorkerCompleted(ByVal sender As System.Object, _
    ByVal e As RunWorkerCompletedEventArgs) Handles backgroundWorker1.RunWorkerCompleted
        If e.Cancelled = True Then
            resultLabel.Text = "Canceled!"
        ElseIf e.Error IsNot Nothing Then
            resultLabel.Text = "Error: " & e.Error.Message
        Else
            resultLabel.Text = "Done!"
        End If
    End Sub
End Class

다음 코드 예제에서는 BackgroundWorker 시간이 많이 걸리는 작업을 비동기적으로 실행 하기 위한 클래스입니다.The following code example demonstrates the use of the BackgroundWorker class for executing a time-consuming operation asynchronously. 다음 그림에서는 출력의 예를 보여 줍니다.The following illustration shows an example of the output.

BackgroundWorker 피보나치 예제BackgroundWorker Fibonacci example

작업 선택한 피보나치 수를 계산 하 고 계산 진행 되 면 진행률 업데이트를 보고 취소할 보류 중인 계산을 허용 합니다.The operation computes the selected Fibonacci number, reports progress updates as the calculation proceeds, and permits a pending calculation to be canceled.

#using <System.Drawing.dll>
#using <System.dll>
#using <System.Windows.Forms.dll>

using namespace System;
using namespace System::Collections;
using namespace System::ComponentModel;
using namespace System::Drawing;
using namespace System::Threading;
using namespace System::Windows::Forms;

public ref class FibonacciForm: public System::Windows::Forms::Form
{
private:

   int numberToCompute;
   int highestPercentageReached;

   System::Windows::Forms::NumericUpDown^ numericUpDown1;
   System::Windows::Forms::Button^ startAsyncButton;
   System::Windows::Forms::Button^ cancelAsyncButton;
   System::Windows::Forms::ProgressBar^ progressBar1;
   System::Windows::Forms::Label ^ resultLabel;
   System::ComponentModel::BackgroundWorker^ backgroundWorker1;

public:
   FibonacciForm()
   {
      InitializeComponent();
      numberToCompute = highestPercentageReached = 0;
      InitializeBackgoundWorker();
   }


private:

   // Set up the BackgroundWorker object by 
   // attaching event handlers. 
   void InitializeBackgoundWorker()
   {
      backgroundWorker1->DoWork += gcnew DoWorkEventHandler( this, &FibonacciForm::backgroundWorker1_DoWork );
      backgroundWorker1->RunWorkerCompleted += gcnew RunWorkerCompletedEventHandler( this, &FibonacciForm::backgroundWorker1_RunWorkerCompleted );
      backgroundWorker1->ProgressChanged += gcnew ProgressChangedEventHandler( this, &FibonacciForm::backgroundWorker1_ProgressChanged );
   }

   void startAsyncButton_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      
      // Reset the text in the result label.
      resultLabel->Text = String::Empty;

      // Disable the UpDown control until 
      // the asynchronous operation is done.
      this->numericUpDown1->Enabled = false;

      // Disable the Start button until 
      // the asynchronous operation is done.
      this->startAsyncButton->Enabled = false;

      // Enable the Cancel button while 
      // the asynchronous operation runs.
      this->cancelAsyncButton->Enabled = true;

      // Get the value from the UpDown control.
      numberToCompute = (int)numericUpDown1->Value;

      // Reset the variable for percentage tracking.
      highestPercentageReached = 0;

      // Start the asynchronous operation.
      backgroundWorker1->RunWorkerAsync( numberToCompute );
   }

   void cancelAsyncButton_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {  
      // Cancel the asynchronous operation.
      this->backgroundWorker1->CancelAsync();
      
      // Disable the Cancel button.
      cancelAsyncButton->Enabled = false;
   }

   // This event handler is where the actual,
   // potentially time-consuming work is done.
   void backgroundWorker1_DoWork( Object^ sender, DoWorkEventArgs^ e )
   {
      // Get the BackgroundWorker that raised this event.
      BackgroundWorker^ worker = dynamic_cast<BackgroundWorker^>(sender);

      // Assign the result of the computation
      // to the Result property of the DoWorkEventArgs
      // object. This is will be available to the 
      // RunWorkerCompleted eventhandler.
      e->Result = ComputeFibonacci( safe_cast<Int32>(e->Argument), worker, e );
   }

   // This event handler deals with the results of the
   // background operation.
   void backgroundWorker1_RunWorkerCompleted( Object^ /*sender*/, RunWorkerCompletedEventArgs^ e )
   {
      // First, handle the case where an exception was thrown.
      if ( e->Error != nullptr )
      {
         MessageBox::Show( e->Error->Message );
      }
      else
      if ( e->Cancelled )
      {
         // Next, handle the case where the user cancelled 
         // the operation.
         // Note that due to a race condition in 
         // the DoWork event handler, the Cancelled
         // flag may not have been set, even though
         // CancelAsync was called.
         resultLabel->Text = "Cancelled";
      }
      else
      {
         // Finally, handle the case where the operation 
         // succeeded.
         resultLabel->Text = e->Result->ToString();
      }

      // Enable the UpDown control.
      this->numericUpDown1->Enabled = true;

      // Enable the Start button.
      startAsyncButton->Enabled = true;

      // Disable the Cancel button.
      cancelAsyncButton->Enabled = false;
   }

   // This event handler updates the progress bar.
   void backgroundWorker1_ProgressChanged( Object^ /*sender*/, ProgressChangedEventArgs^ e )
   {
      this->progressBar1->Value = e->ProgressPercentage;
   }

   // This is the method that does the actual work. For this
   // example, it computes a Fibonacci number and
   // reports progress as it does its work.
   long ComputeFibonacci( int n, BackgroundWorker^ worker, DoWorkEventArgs ^ e )
   {
      // The parameter n must be >= 0 and <= 91.
      // Fib(n), with n > 91, overflows a long.
      if ( (n < 0) || (n > 91) )
      {
         throw gcnew ArgumentException( "value must be >= 0 and <= 91","n" );
      }

      long result = 0;
      
      // Abort the operation if the user has cancelled.
      // Note that a call to CancelAsync may have set 
      // CancellationPending to true just after the
      // last invocation of this method exits, so this 
      // code will not have the opportunity to set the 
      // DoWorkEventArgs.Cancel flag to true. This means
      // that RunWorkerCompletedEventArgs.Cancelled will
      // not be set to true in your RunWorkerCompleted
      // event handler. This is a race condition.
      if ( worker->CancellationPending )
      {
         e->Cancel = true;
      }
      else
      {
         if ( n < 2 )
         {
            result = 1;
         }
         else
         {
            result = ComputeFibonacci( n - 1, worker, e ) + ComputeFibonacci( n - 2, worker, e );
         }

         // Report progress as a percentage of the total task.
         int percentComplete = (int)((float)n / (float)numberToCompute * 100);
         if ( percentComplete > highestPercentageReached )
         {
            highestPercentageReached = percentComplete;
            worker->ReportProgress( percentComplete );
         }
      }

      return result;
   }

   void InitializeComponent()
   {
      this->numericUpDown1 = gcnew System::Windows::Forms::NumericUpDown;
      this->startAsyncButton = gcnew System::Windows::Forms::Button;
      this->cancelAsyncButton = gcnew System::Windows::Forms::Button;
      this->resultLabel = gcnew System::Windows::Forms::Label;
      this->progressBar1 = gcnew System::Windows::Forms::ProgressBar;
      this->backgroundWorker1 = gcnew System::ComponentModel::BackgroundWorker;
      (dynamic_cast<System::ComponentModel::ISupportInitialize^>(this->numericUpDown1))->BeginInit();
      this->SuspendLayout();
      
      // 
      // numericUpDown1
      // 
      this->numericUpDown1->Location = System::Drawing::Point( 16, 16 );
      array<Int32>^temp0 = {91,0,0,0};
      this->numericUpDown1->Maximum = System::Decimal( temp0 );
      array<Int32>^temp1 = {1,0,0,0};
      this->numericUpDown1->Minimum = System::Decimal( temp1 );
      this->numericUpDown1->Name = "numericUpDown1";
      this->numericUpDown1->Size = System::Drawing::Size( 80, 20 );
      this->numericUpDown1->TabIndex = 0;
      array<Int32>^temp2 = {1,0,0,0};
      this->numericUpDown1->Value = System::Decimal( temp2 );

      // 
      // startAsyncButton
      // 
      this->startAsyncButton->Location = System::Drawing::Point( 16, 72 );
      this->startAsyncButton->Name = "startAsyncButton";
      this->startAsyncButton->Size = System::Drawing::Size( 120, 23 );
      this->startAsyncButton->TabIndex = 1;
      this->startAsyncButton->Text = "Start Async";
      this->startAsyncButton->Click += gcnew System::EventHandler( this, &FibonacciForm::startAsyncButton_Click );

      // 
      // cancelAsyncButton
      // 
      this->cancelAsyncButton->Enabled = false;
      this->cancelAsyncButton->Location = System::Drawing::Point( 153, 72 );
      this->cancelAsyncButton->Name = "cancelAsyncButton";
      this->cancelAsyncButton->Size = System::Drawing::Size( 119, 23 );
      this->cancelAsyncButton->TabIndex = 2;
      this->cancelAsyncButton->Text = "Cancel Async";
      this->cancelAsyncButton->Click += gcnew System::EventHandler( this, &FibonacciForm::cancelAsyncButton_Click );

      // 
      // resultLabel
      // 
      this->resultLabel->BorderStyle = System::Windows::Forms::BorderStyle::Fixed3D;
      this->resultLabel->Location = System::Drawing::Point( 112, 16 );
      this->resultLabel->Name = "resultLabel";
      this->resultLabel->Size = System::Drawing::Size( 160, 23 );
      this->resultLabel->TabIndex = 3;
      this->resultLabel->Text = "(no result)";
      this->resultLabel->TextAlign = System::Drawing::ContentAlignment::MiddleCenter;

      // 
      // progressBar1
      // 
      this->progressBar1->Location = System::Drawing::Point( 18, 48 );
      this->progressBar1->Name = "progressBar1";
      this->progressBar1->Size = System::Drawing::Size( 256, 8 );
      this->progressBar1->Step = 2;
      this->progressBar1->TabIndex = 4;

      // 
      // backgroundWorker1
      // 
      this->backgroundWorker1->WorkerReportsProgress = true;
      this->backgroundWorker1->WorkerSupportsCancellation = true;

      // 
      // FibonacciForm
      // 
      this->ClientSize = System::Drawing::Size( 292, 118 );
      this->Controls->Add( this->progressBar1 );
      this->Controls->Add( this->resultLabel );
      this->Controls->Add( this->cancelAsyncButton );
      this->Controls->Add( this->startAsyncButton );
      this->Controls->Add( this->numericUpDown1 );
      this->Name = "FibonacciForm";
      this->Text = "Fibonacci Calculator";
      (dynamic_cast<System::ComponentModel::ISupportInitialize^>(this->numericUpDown1))->EndInit();
      this->ResumeLayout( false );
   }
};

[STAThread]
int main()
{
   Application::Run( gcnew FibonacciForm );
}
using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;

namespace BackgroundWorkerExample
{	
    public class FibonacciForm : System.Windows.Forms.Form
    {	
        private int numberToCompute = 0;
        private int highestPercentageReached = 0;

        private System.Windows.Forms.NumericUpDown numericUpDown1;
        private System.Windows.Forms.Button startAsyncButton;
        private System.Windows.Forms.Button cancelAsyncButton;
        private System.Windows.Forms.ProgressBar progressBar1;
        private System.Windows.Forms.Label resultLabel;
        private System.ComponentModel.BackgroundWorker backgroundWorker1;

        public FibonacciForm()
        {	
            InitializeComponent();

            InitializeBackgroundWorker();
        }

        // Set up the BackgroundWorker object by 
        // attaching event handlers. 
        private void InitializeBackgroundWorker()
        {
            backgroundWorker1.DoWork += 
                new DoWorkEventHandler(backgroundWorker1_DoWork);
            backgroundWorker1.RunWorkerCompleted += 
                new RunWorkerCompletedEventHandler(
            backgroundWorker1_RunWorkerCompleted);
            backgroundWorker1.ProgressChanged += 
                new ProgressChangedEventHandler(
            backgroundWorker1_ProgressChanged);
        }
    
        private void startAsyncButton_Click(System.Object sender, 
            System.EventArgs e)
        {
            // Reset the text in the result label.
            resultLabel.Text = String.Empty;

            // Disable the UpDown control until 
            // the asynchronous operation is done.
            this.numericUpDown1.Enabled = false;

            // Disable the Start button until 
            // the asynchronous operation is done.
            this.startAsyncButton.Enabled = false;

            // Enable the Cancel button while 
            // the asynchronous operation runs.
            this.cancelAsyncButton.Enabled = true;

            // Get the value from the UpDown control.
            numberToCompute = (int)numericUpDown1.Value;

            // Reset the variable for percentage tracking.
            highestPercentageReached = 0;

            // Start the asynchronous operation.
            backgroundWorker1.RunWorkerAsync(numberToCompute);
        }

        private void cancelAsyncButton_Click(System.Object sender, 
            System.EventArgs e)
        {   
            // Cancel the asynchronous operation.
            this.backgroundWorker1.CancelAsync();

            // Disable the Cancel button.
            cancelAsyncButton.Enabled = false;
        }

        // This event handler is where the actual,
        // potentially time-consuming work is done.
        private void backgroundWorker1_DoWork(object sender, 
            DoWorkEventArgs e)
        {   
            // Get the BackgroundWorker that raised this event.
            BackgroundWorker worker = sender as BackgroundWorker;

            // Assign the result of the computation
            // to the Result property of the DoWorkEventArgs
            // object. This is will be available to the 
            // RunWorkerCompleted eventhandler.
            e.Result = ComputeFibonacci((int)e.Argument, worker, e);
        }

        // This event handler deals with the results of the
        // background operation.
        private void backgroundWorker1_RunWorkerCompleted(
            object sender, RunWorkerCompletedEventArgs e)
        {
            // First, handle the case where an exception was thrown.
            if (e.Error != null)
            {
                MessageBox.Show(e.Error.Message);
            }
            else if (e.Cancelled)
            {
                // Next, handle the case where the user canceled 
                // the operation.
                // Note that due to a race condition in 
                // the DoWork event handler, the Cancelled
                // flag may not have been set, even though
                // CancelAsync was called.
                resultLabel.Text = "Canceled";
            }
            else
            {
                // Finally, handle the case where the operation 
                // succeeded.
                resultLabel.Text = e.Result.ToString();
            }

            // Enable the UpDown control.
            this.numericUpDown1.Enabled = true;

            // Enable the Start button.
            startAsyncButton.Enabled = true;

            // Disable the Cancel button.
            cancelAsyncButton.Enabled = false;
        }

        // This event handler updates the progress bar.
        private void backgroundWorker1_ProgressChanged(object sender,
            ProgressChangedEventArgs e)
        {
            this.progressBar1.Value = e.ProgressPercentage;
        }

        // This is the method that does the actual work. For this
        // example, it computes a Fibonacci number and
        // reports progress as it does its work.
        long ComputeFibonacci(int n, BackgroundWorker worker, DoWorkEventArgs e)
        {
            // The parameter n must be >= 0 and <= 91.
            // Fib(n), with n > 91, overflows a long.
            if ((n < 0) || (n > 91))
            {
                throw new ArgumentException(
                    "value must be >= 0 and <= 91", "n");
            }

            long result = 0;

            // Abort the operation if the user has canceled.
            // Note that a call to CancelAsync may have set 
            // CancellationPending to true just after the
            // last invocation of this method exits, so this 
            // code will not have the opportunity to set the 
            // DoWorkEventArgs.Cancel flag to true. This means
            // that RunWorkerCompletedEventArgs.Cancelled will
            // not be set to true in your RunWorkerCompleted
            // event handler. This is a race condition.

            if (worker.CancellationPending)
            {   
                e.Cancel = true;
            }
            else
            {   
                if (n < 2)
                {   
                    result = 1;
                }
                else
                {   
                    result = ComputeFibonacci(n - 1, worker, e) + 
                             ComputeFibonacci(n - 2, worker, e);
                }

                // Report progress as a percentage of the total task.
                int percentComplete = 
                    (int)((float)n / (float)numberToCompute * 100);
                if (percentComplete > highestPercentageReached)
                {
                    highestPercentageReached = percentComplete;
                    worker.ReportProgress(percentComplete);
                }
            }

            return result;
        }


        #region Windows Form Designer generated code
        
        private void InitializeComponent()
        {
            this.numericUpDown1 = new System.Windows.Forms.NumericUpDown();
            this.startAsyncButton = new System.Windows.Forms.Button();
            this.cancelAsyncButton = new System.Windows.Forms.Button();
            this.resultLabel = new System.Windows.Forms.Label();
            this.progressBar1 = new System.Windows.Forms.ProgressBar();
            this.backgroundWorker1 = new System.ComponentModel.BackgroundWorker();
            ((System.ComponentModel.ISupportInitialize)(this.numericUpDown1)).BeginInit();
            this.SuspendLayout();
            // 
            // numericUpDown1
            // 
            this.numericUpDown1.Location = new System.Drawing.Point(16, 16);
            this.numericUpDown1.Maximum = new System.Decimal(new int[] {
            91,
            0,
            0,
            0});
            this.numericUpDown1.Minimum = new System.Decimal(new int[] {
            1,
            0,
            0,
            0});
            this.numericUpDown1.Name = "numericUpDown1";
            this.numericUpDown1.Size = new System.Drawing.Size(80, 20);
            this.numericUpDown1.TabIndex = 0;
            this.numericUpDown1.Value = new System.Decimal(new int[] {
            1,
            0,
            0,
            0});
            // 
            // startAsyncButton
            // 
            this.startAsyncButton.Location = new System.Drawing.Point(16, 72);
            this.startAsyncButton.Name = "startAsyncButton";
            this.startAsyncButton.Size = new System.Drawing.Size(120, 23);
            this.startAsyncButton.TabIndex = 1;
            this.startAsyncButton.Text = "Start Async";
            this.startAsyncButton.Click += new System.EventHandler(this.startAsyncButton_Click);
            // 
            // cancelAsyncButton
            // 
            this.cancelAsyncButton.Enabled = false;
            this.cancelAsyncButton.Location = new System.Drawing.Point(153, 72);
            this.cancelAsyncButton.Name = "cancelAsyncButton";
            this.cancelAsyncButton.Size = new System.Drawing.Size(119, 23);
            this.cancelAsyncButton.TabIndex = 2;
            this.cancelAsyncButton.Text = "Cancel Async";
            this.cancelAsyncButton.Click += new System.EventHandler(this.cancelAsyncButton_Click);
            // 
            // resultLabel
            // 
            this.resultLabel.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
            this.resultLabel.Location = new System.Drawing.Point(112, 16);
            this.resultLabel.Name = "resultLabel";
            this.resultLabel.Size = new System.Drawing.Size(160, 23);
            this.resultLabel.TabIndex = 3;
            this.resultLabel.Text = "(no result)";
            this.resultLabel.TextAlign = System.Drawing.ContentAlignment.MiddleCenter;
            // 
            // progressBar1
            // 
            this.progressBar1.Location = new System.Drawing.Point(18, 48);
            this.progressBar1.Name = "progressBar1";
            this.progressBar1.Size = new System.Drawing.Size(256, 8);
            this.progressBar1.Step = 2;
            this.progressBar1.TabIndex = 4;
            // 
            // backgroundWorker1
            // 
            this.backgroundWorker1.WorkerReportsProgress = true;
            this.backgroundWorker1.WorkerSupportsCancellation = true;
            // 
            // FibonacciForm
            // 
            this.ClientSize = new System.Drawing.Size(292, 118);
            this.Controls.Add(this.progressBar1);
            this.Controls.Add(this.resultLabel);
            this.Controls.Add(this.cancelAsyncButton);
            this.Controls.Add(this.startAsyncButton);
            this.Controls.Add(this.numericUpDown1);
            this.Name = "FibonacciForm";
            this.Text = "Fibonacci Calculator";
            ((System.ComponentModel.ISupportInitialize)(this.numericUpDown1)).EndInit();
            this.ResumeLayout(false);

        }
        #endregion

        [STAThread]
        static void Main()
        {
            Application.Run(new FibonacciForm());
        }
    }
}
Imports System.Collections
Imports System.ComponentModel
Imports System.Drawing
Imports System.Threading
Imports System.Windows.Forms

Public Class FibonacciForm
    Inherits System.Windows.Forms.Form

    Private numberToCompute As Integer = 0
    Private highestPercentageReached As Integer = 0

    Private numericUpDown1 As System.Windows.Forms.NumericUpDown
    Private WithEvents startAsyncButton As System.Windows.Forms.Button
    Private WithEvents cancelAsyncButton As System.Windows.Forms.Button
    Private progressBar1 As System.Windows.Forms.ProgressBar
    Private resultLabel As System.Windows.Forms.Label
    Private WithEvents backgroundWorker1 As System.ComponentModel.BackgroundWorker


    Public Sub New()
        InitializeComponent()
    End Sub

    Private Sub startAsyncButton_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) _
    Handles startAsyncButton.Click

        ' Reset the text in the result label.
        resultLabel.Text = [String].Empty

        ' Disable the UpDown control until 
        ' the asynchronous operation is done.
        Me.numericUpDown1.Enabled = False

        ' Disable the Start button until 
        ' the asynchronous operation is done.
        Me.startAsyncButton.Enabled = False

        ' Enable the Cancel button while 
        ' the asynchronous operation runs.
        Me.cancelAsyncButton.Enabled = True

        ' Get the value from the UpDown control.
        numberToCompute = CInt(numericUpDown1.Value)

        ' Reset the variable for percentage tracking.
        highestPercentageReached = 0


        ' Start the asynchronous operation.
        backgroundWorker1.RunWorkerAsync(numberToCompute)
    End Sub 

    Private Sub cancelAsyncButton_Click( _
    ByVal sender As System.Object, _
    ByVal e As System.EventArgs) _
    Handles cancelAsyncButton.Click
        
        ' Cancel the asynchronous operation.
        Me.backgroundWorker1.CancelAsync()

        ' Disable the Cancel button.
        cancelAsyncButton.Enabled = False
        
    End Sub

    ' This event handler is where the actual work is done.
    Private Sub backgroundWorker1_DoWork( _
    ByVal sender As Object, _
    ByVal e As DoWorkEventArgs) _
    Handles backgroundWorker1.DoWork

        ' Get the BackgroundWorker object that raised this event.
        Dim worker As BackgroundWorker = _
            CType(sender, BackgroundWorker)

        ' Assign the result of the computation
        ' to the Result property of the DoWorkEventArgs
        ' object. This is will be available to the 
        ' RunWorkerCompleted eventhandler.
        e.Result = ComputeFibonacci(e.Argument, worker, e)
    End Sub

    ' This event handler deals with the results of the
    ' background operation.
    Private Sub backgroundWorker1_RunWorkerCompleted( _
    ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs) _
    Handles backgroundWorker1.RunWorkerCompleted

        ' First, handle the case where an exception was thrown.
        If (e.Error IsNot Nothing) Then
            MessageBox.Show(e.Error.Message)
        ElseIf e.Cancelled Then
            ' Next, handle the case where the user canceled the 
            ' operation.
            ' Note that due to a race condition in 
            ' the DoWork event handler, the Cancelled
            ' flag may not have been set, even though
            ' CancelAsync was called.
            resultLabel.Text = "Canceled"
        Else
            ' Finally, handle the case where the operation succeeded.
            resultLabel.Text = e.Result.ToString()
        End If

        ' Enable the UpDown control.
        Me.numericUpDown1.Enabled = True

        ' Enable the Start button.
        startAsyncButton.Enabled = True

        ' Disable the Cancel button.
        cancelAsyncButton.Enabled = False
    End Sub

    ' This event handler updates the progress bar.
    Private Sub backgroundWorker1_ProgressChanged( _
    ByVal sender As Object, ByVal e As ProgressChangedEventArgs) _
    Handles backgroundWorker1.ProgressChanged

        Me.progressBar1.Value = e.ProgressPercentage

    End Sub

    ' This is the method that does the actual work. For this
    ' example, it computes a Fibonacci number and
    ' reports progress as it does its work.
    Function ComputeFibonacci( _
        ByVal n As Integer, _
        ByVal worker As BackgroundWorker, _
        ByVal e As DoWorkEventArgs) As Long

        ' The parameter n must be >= 0 and <= 91.
        ' Fib(n), with n > 91, overflows a long.
        If n < 0 OrElse n > 91 Then
            Throw New ArgumentException( _
                "value must be >= 0 and <= 91", "n")
        End If

        Dim result As Long = 0

        ' Abort the operation if the user has canceled.
        ' Note that a call to CancelAsync may have set 
        ' CancellationPending to true just after the
        ' last invocation of this method exits, so this 
        ' code will not have the opportunity to set the 
        ' DoWorkEventArgs.Cancel flag to true. This means
        ' that RunWorkerCompletedEventArgs.Cancelled will
        ' not be set to true in your RunWorkerCompleted
        ' event handler. This is a race condition.
        If worker.CancellationPending Then
            e.Cancel = True
        Else
            If n < 2 Then
                result = 1
            Else
                result = ComputeFibonacci(n - 1, worker, e) + _
                         ComputeFibonacci(n - 2, worker, e)
            End If

            ' Report progress as a percentage of the total task.
            Dim percentComplete As Integer = _
                CSng(n) / CSng(numberToCompute) * 100
            If percentComplete > highestPercentageReached Then
                highestPercentageReached = percentComplete
                worker.ReportProgress(percentComplete)
            End If

        End If

        Return result

    End Function


    Private Sub InitializeComponent()
        Me.numericUpDown1 = New System.Windows.Forms.NumericUpDown
        Me.startAsyncButton = New System.Windows.Forms.Button
        Me.cancelAsyncButton = New System.Windows.Forms.Button
        Me.resultLabel = New System.Windows.Forms.Label
        Me.progressBar1 = New System.Windows.Forms.ProgressBar
        Me.backgroundWorker1 = New System.ComponentModel.BackgroundWorker
        CType(Me.numericUpDown1, System.ComponentModel.ISupportInitialize).BeginInit()
        Me.SuspendLayout()
        '
        'numericUpDown1
        '
        Me.numericUpDown1.Location = New System.Drawing.Point(16, 16)
        Me.numericUpDown1.Maximum = New Decimal(New Integer() {91, 0, 0, 0})
        Me.numericUpDown1.Minimum = New Decimal(New Integer() {1, 0, 0, 0})
        Me.numericUpDown1.Name = "numericUpDown1"
        Me.numericUpDown1.Size = New System.Drawing.Size(80, 20)
        Me.numericUpDown1.TabIndex = 0
        Me.numericUpDown1.Value = New Decimal(New Integer() {1, 0, 0, 0})
        '
        'startAsyncButton
        '
        Me.startAsyncButton.Location = New System.Drawing.Point(16, 72)
        Me.startAsyncButton.Name = "startAsyncButton"
        Me.startAsyncButton.Size = New System.Drawing.Size(120, 23)
        Me.startAsyncButton.TabIndex = 1
        Me.startAsyncButton.Text = "Start Async"
        '
        'cancelAsyncButton
        '
        Me.cancelAsyncButton.Enabled = False
        Me.cancelAsyncButton.Location = New System.Drawing.Point(153, 72)
        Me.cancelAsyncButton.Name = "cancelAsyncButton"
        Me.cancelAsyncButton.Size = New System.Drawing.Size(119, 23)
        Me.cancelAsyncButton.TabIndex = 2
        Me.cancelAsyncButton.Text = "Cancel Async"
        '
        'resultLabel
        '
        Me.resultLabel.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.resultLabel.Location = New System.Drawing.Point(112, 16)
        Me.resultLabel.Name = "resultLabel"
        Me.resultLabel.Size = New System.Drawing.Size(160, 23)
        Me.resultLabel.TabIndex = 3
        Me.resultLabel.Text = "(no result)"
        Me.resultLabel.TextAlign = System.Drawing.ContentAlignment.MiddleCenter
        '
        'progressBar1
        '
        Me.progressBar1.Location = New System.Drawing.Point(18, 48)
        Me.progressBar1.Name = "progressBar1"
        Me.progressBar1.Size = New System.Drawing.Size(256, 8)
        Me.progressBar1.TabIndex = 4
        '
        'backgroundWorker1
        '
        Me.backgroundWorker1.WorkerReportsProgress = True
        Me.backgroundWorker1.WorkerSupportsCancellation = True
        '
        'FibonacciForm
        '
        Me.ClientSize = New System.Drawing.Size(292, 118)
        Me.Controls.Add(Me.progressBar1)
        Me.Controls.Add(Me.resultLabel)
        Me.Controls.Add(Me.cancelAsyncButton)
        Me.Controls.Add(Me.startAsyncButton)
        Me.Controls.Add(Me.numericUpDown1)
        Me.Name = "FibonacciForm"
        Me.Text = "Fibonacci Calculator"
        CType(Me.numericUpDown1, System.ComponentModel.ISupportInitialize).EndInit()
        Me.ResumeLayout(False)

    End Sub

    <STAThread()> _
    Shared Sub Main()
        Application.Run(New FibonacciForm)
    End Sub
End Class

설명

BackgroundWorker 클래스를 사용 하면 별도 전용 스레드에서 작업을 실행할 수 있습니다.The BackgroundWorker class allows you to run an operation on a separate, dedicated thread. 다운로드 및 데이터베이스 트랜잭션과 같은 시간이 많이 걸리는 작업은 사용자 인터페이스 (UI) 실행 하 고 응답을 멈춘 것 처럼 보일 수 발생할 수 있습니다.Time-consuming operations like downloads and database transactions can cause your user interface (UI) to seem as though it has stopped responding while they are running. 이러한 작업으로 인 한 지연이 길어지는 경우 및 응답성이 뛰어난 UI를 구성할 때의 BackgroundWorker 클래스는 편리 하 게 솔루션을 제공 합니다.When you want a responsive UI and you are faced with long delays associated with such operations, the BackgroundWorker class provides a convenient solution.

시간이 많이 걸리는 작업을 백그라운드에서를 실행 하려면 만들기를 BackgroundWorker 작업이 완료 되 면 신호 확인 하 고 작업의 진행률을 보고 하는 이벤트를 수신 합니다.To execute a time-consuming operation in the background, create a BackgroundWorker and listen for events that report the progress of your operation and signal when your operation is finished. 만들 수 있습니다는 BackgroundWorker 프로그래밍 방식으로에서 폼으로 끌어 놓을 수 있습니다 합니다 구성 요소 탭의 도구 상자.You can create the BackgroundWorker programmatically or you can drag it onto your form from the Components tab of the Toolbox. 만드는 경우는 BackgroundWorker Windows Forms 디자이너에서 구성 요소 트레이에 표시 됩니다 하 고 해당 속성이 속성 창에 표시 됩니다.If you create the BackgroundWorker in the Windows Forms Designer, it will appear in the Component Tray, and its properties will be displayed in the Properties window.

백그라운드 작업에 대 한 설정에 대 한 이벤트 처리기를 추가 합니다 DoWork 이벤트입니다.To set up for a background operation, add an event handler for the DoWork event. 이 이벤트 처리기에서 시간이 오래 걸리는 작업을 호출 합니다.Call your time-consuming operation in this event handler. 작업을 시작 하려면 호출 RunWorkerAsync합니다.To start the operation, call RunWorkerAsync. 진행률 업데이트의 알림을 받으려면 처리는 ProgressChanged 이벤트입니다.To receive notifications of progress updates, handle the ProgressChanged event. 작업이 완료 될 때 알림을 받으려면 처리는 RunWorkerCompleted 이벤트입니다.To receive a notification when the operation is completed, handle the RunWorkerCompleted event.

참고

사용자 인터페이스 개체를 조작 하지 않도록 주의 해야 프로그램 DoWork 이벤트 처리기입니다.You must be careful not to manipulate any user-interface objects in your DoWork event handler. 대신, 사용자 인터페이스를 통해 통신 합니다 ProgressChangedRunWorkerCompleted 이벤트입니다.Instead, communicate to the user interface through the ProgressChanged and RunWorkerCompleted events.

BackgroundWorker 이벤트에서 마샬링되지는 AppDomain 경계입니다.BackgroundWorker events are not marshaled across AppDomain boundaries. 사용 하지 마십시오는 BackgroundWorker 구성 요소에서 둘 이상의 다중 스레드 작업을 수행할 AppDomain합니다.Do not use a BackgroundWorker component to perform multithreaded operations in more than one AppDomain.

백그라운드 작업에 매개 변수가 필요 합니다 호출 RunWorkerAsync 매개 변수를 사용 하 여 합니다.If your background operation requires a parameter, call RunWorkerAsync with your parameter. 내 합니다 DoWork 이벤트 처리기에서 매개 변수를 추출할 수 있습니다는 DoWorkEventArgs.Argument 속성입니다.Inside the DoWork event handler, you can extract the parameter from the DoWorkEventArgs.Argument property.

BackgroundWorker에 대한 자세한 내용은 방법: 백그라운드에서 작업 실행을 참조하세요.For more information about BackgroundWorker, see How to: Run an Operation in the Background.

생성자

BackgroundWorker() BackgroundWorker() BackgroundWorker() BackgroundWorker()

BackgroundWorker 클래스의 새 인스턴스를 초기화합니다.Initializes a new instance of the BackgroundWorker class.

속성

CancellationPending CancellationPending CancellationPending CancellationPending

애플리케이션에서 백그라운드 작업의 취소를 요청했는지 여부를 나타내는 값을 가져옵니다.Gets a value indicating whether the application has requested cancellation of a background operation.

CanRaiseEvents CanRaiseEvents CanRaiseEvents CanRaiseEvents

구성 요소가 이벤트를 발생시킬 수 있는지 여부를 나타내는 값을 가져옵니다.Gets a value indicating whether the component can raise an event.

(Inherited from Component)
Container Container Container Container

IContainer가 포함된 Component를 가져옵니다.Gets the IContainer that contains the Component.

(Inherited from Component)
DesignMode DesignMode DesignMode DesignMode

Component가 현재 디자인 모드인지 여부를 나타내는 값을 가져옵니다.Gets a value that indicates whether the Component is currently in design mode.

(Inherited from Component)
Events Events Events Events

Component에 연결된 이벤트 처리기의 목록을 가져옵니다.Gets the list of event handlers that are attached to this Component.

(Inherited from Component)
IsBusy IsBusy IsBusy IsBusy

BackgroundWorker가 비동기 작업을 실행하고 있는지 여부를 나타내는 값을 가져옵니다.Gets a value indicating whether the BackgroundWorker is running an asynchronous operation.

Site Site Site Site

ComponentISite를 가져오거나 설정합니다.Gets or sets the ISite of the Component.

(Inherited from Component)
WorkerReportsProgress WorkerReportsProgress WorkerReportsProgress WorkerReportsProgress

BackgroundWorker가 진행률 업데이트를 보고할 수 있는지 여부를 나타내는 값을 가져오거나 설정합니다.Gets or sets a value indicating whether the BackgroundWorker can report progress updates.

WorkerSupportsCancellation WorkerSupportsCancellation WorkerSupportsCancellation WorkerSupportsCancellation

BackgroundWorker가 비동기 취소를 지원하는지 여부를 나타내는 값을 가져오거나 설정합니다.Gets or sets a value indicating whether the BackgroundWorker supports asynchronous cancellation.

메서드

CancelAsync() CancelAsync() CancelAsync() CancelAsync()

보류 중인 백그라운드 작업의 취소를 요청합니다.Requests cancellation of a pending background operation.

CreateObjRef(Type) CreateObjRef(Type) CreateObjRef(Type) CreateObjRef(Type)

원격 개체와 통신하는 데 사용되는 프록시 생성에 필요한 모든 관련 정보가 들어 있는 개체를 만듭니다.Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object.

(Inherited from MarshalByRefObject)
Dispose() Dispose() Dispose() Dispose()
Dispose(Boolean) Dispose(Boolean) Dispose(Boolean) Dispose(Boolean)
Equals(Object) Equals(Object) Equals(Object) Equals(Object)

지정한 개체와 현재 개체가 같은지 여부를 확인합니다.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

기본 해시 함수로 작동합니다.Serves as the default hash function.

(Inherited from Object)
GetLifetimeService() GetLifetimeService() GetLifetimeService() GetLifetimeService()

이 인스턴스의 수명 정책을 제어하는 현재의 수명 서비스 개체를 검색합니다.Retrieves the current lifetime service object that controls the lifetime policy for this instance.

(Inherited from MarshalByRefObject)
GetService(Type) GetService(Type) GetService(Type) GetService(Type)

Component 또는 해당 Container에서 제공하는 서비스를 나타내는 개체를 반환합니다.Returns an object that represents a service provided by the Component or by its Container.

(Inherited from Component)
GetType() GetType() GetType() GetType()

현재 인스턴스의 Type을 가져옵니다.Gets the Type of the current instance.

(Inherited from Object)
InitializeLifetimeService() InitializeLifetimeService() InitializeLifetimeService() InitializeLifetimeService()

이 인스턴스의 수명 정책을 제어하는 수명 서비스 개체를 가져옵니다.Obtains a lifetime service object to control the lifetime policy for this instance.

(Inherited from MarshalByRefObject)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

현재 Object의 단순 복사본을 만듭니다.Creates a shallow copy of the current Object.

(Inherited from Object)
MemberwiseClone(Boolean) MemberwiseClone(Boolean) MemberwiseClone(Boolean) MemberwiseClone(Boolean)

현재 MarshalByRefObject 개체의 단순 복사본을 만듭니다.Creates a shallow copy of the current MarshalByRefObject object.

(Inherited from MarshalByRefObject)
OnDoWork(DoWorkEventArgs) OnDoWork(DoWorkEventArgs) OnDoWork(DoWorkEventArgs) OnDoWork(DoWorkEventArgs)

DoWork 이벤트를 발생시킵니다.Raises the DoWork event.

OnProgressChanged(ProgressChangedEventArgs) OnProgressChanged(ProgressChangedEventArgs) OnProgressChanged(ProgressChangedEventArgs) OnProgressChanged(ProgressChangedEventArgs)

ProgressChanged 이벤트를 발생시킵니다.Raises the ProgressChanged event.

OnRunWorkerCompleted(RunWorkerCompletedEventArgs) OnRunWorkerCompleted(RunWorkerCompletedEventArgs) OnRunWorkerCompleted(RunWorkerCompletedEventArgs) OnRunWorkerCompleted(RunWorkerCompletedEventArgs)

RunWorkerCompleted 이벤트를 발생시킵니다.Raises the RunWorkerCompleted event.

ReportProgress(Int32) ReportProgress(Int32) ReportProgress(Int32) ReportProgress(Int32)

ProgressChanged 이벤트를 발생시킵니다.Raises the ProgressChanged event.

ReportProgress(Int32, Object) ReportProgress(Int32, Object) ReportProgress(Int32, Object) ReportProgress(Int32, Object)

ProgressChanged 이벤트를 발생시킵니다.Raises the ProgressChanged event.

RunWorkerAsync() RunWorkerAsync() RunWorkerAsync() RunWorkerAsync()

백그라운드 작업의 실행을 시작합니다.Starts execution of a background operation.

RunWorkerAsync(Object) RunWorkerAsync(Object) RunWorkerAsync(Object) RunWorkerAsync(Object)

백그라운드 작업의 실행을 시작합니다.Starts execution of a background operation.

ToString() ToString() ToString() ToString()

Component의 이름이 포함된 String을 반환합니다(있는 경우).Returns a String containing the name of the Component, if any. 이 메서드는 재정의할 수 없습니다.This method should not be overridden.

(Inherited from Component)

이벤트

Disposed Disposed Disposed Disposed

Dispose() 메서드를 호출하여 구성 요소가 삭제되는 경우 발생합니다.Occurs when the component is disposed by a call to the Dispose() method.

(Inherited from Component)
DoWork DoWork DoWork DoWork

RunWorkerAsync()가 호출될 때 발생합니다.Occurs when RunWorkerAsync() is called.

ProgressChanged ProgressChanged ProgressChanged ProgressChanged

ReportProgress(Int32)가 호출될 때 발생합니다.Occurs when ReportProgress(Int32) is called.

RunWorkerCompleted RunWorkerCompleted RunWorkerCompleted RunWorkerCompleted

백그라운드 작업이 완료되거나 취소되거나 예외를 발생시켰을 때 발생합니다.Occurs when the background operation has completed, has been canceled, or has raised an exception.

적용 대상

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