BackgroundWorker.ReportProgress Method (Int32, Object) (System.ComponentModel)

ReportProgress Method (Int32, Objec...

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Microsoft Visual Studio 2008/.NET Framework 3.5

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.NET Framework Class Library

BackgroundWorker..::.ReportProgress Method (Int32, Object)

Updated: November 2007

Raises the ProgressChanged event.

Namespace: System.ComponentModel
Assembly: System (in System.dll)

Syntax

Visual Basic (Declaration)

Public Sub ReportProgress ( _
    percentProgress As Integer, _
    userState As Object _
)

Visual Basic (Usage)

Dim instance As BackgroundWorker
Dim percentProgress As Integer
Dim userState As Object

instance.ReportProgress(percentProgress, _
    userState)

public void ReportProgress(
    int percentProgress,
    Object userState
)

Visual C++

public:
void ReportProgress(
    int percentProgress, 
    Object^ userState
)

public void ReportProgress(
    int percentProgress,
    Object userState
)

JScript

public function ReportProgress(
    percentProgress : int, 
    userState : Object
)

Parameters

percentProgress: Type: System..::.Int32
The percentage, from 0 to 100, of the background operation that is complete.

userState: Type: System..::.Object
The state object passed to RunWorkerAsync.

Exceptions

Exception	Condition
InvalidOperationException	The WorkerReportsProgress property is set to false.

Remarks

If you need the background operation to report on its progress, you can call the ReportProgress method to raise the ProgressChanged event. The WorkerReportsProgress property value must true, or ReportProgress will throw an InvalidOperationException.

It is up to you to implement a meaningful way of measuring your background operation's progress as a percentage of the total task completed.

Examples

The following code example demonstrates the use of the ReportProgress method to report the progress of an asynchronous operation to the user. This code example is part of a larger example provided for the ToolStripProgressBar class.

Visual Basic

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

    private 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!");
    }

Platforms

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information