Backgroundworker + wpf & # 8594; frozen window

Question

-progressbar is always 0%

- froozen window (while DoWork r.)

-if System.threading.thread.sleep (1) on - works great

What is the problem?

private void btnNext_Click(object sender, RoutedEventArgs e)
{
  this._worker = new BackgroundWorker();
  this._worker.DoWork += delegate(object s, DoWorkEventArgs args)
            {
                long current = 1;
                long max = generalMaxSzam();


                for (int i = 1; i <= 30; i++)
                {
                    for (int j = i+1; j <= 30; j++)
                    {
                        for (int c = j+1; c <= 30; c++)
                        {
                            for (int h = c+1; h <= 30; h++)
                            {
                                for (int d = h+1; d <= 30; d++)
                                {
                                    int percent = Convert.ToInt32(((decimal)current / (decimal)max) * 100);
                                    this._worker.ReportProgress(percent);
                                    current++;
                                    //System.Threading.Thread.Sleep(1); - it works well
                                }
                            }
                        }
                    }
                }
            };

            this._worker.WorkerReportsProgress = true;

 this._worker.RunWorkerCompleted += delegate(object s, RunWorkerCompletedEventArgs args)
            {
                this.Close();
            };

 this._worker.ProgressChanged += delegate(object s, ProgressChangedEventArgs args)
            {                              
                this.statusPG.Value = args.ProgressPercentage;             
            };

 this._worker.RunWorkerAsync();
}

<Window x:Class="SzerencsejatekProgram.Create"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Létrehozás" mc:Ignorable="d" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" Height="500" Width="700">    
    <DockPanel>    
        <Button DockPanel.Dock="Right"  Name="btnNext" Width="80" Click="btnNext_Click">Tovább</Button>
        <StatusBar DockPanel.Dock="Bottom">
            <StatusBar.ItemsPanel>
                <ItemsPanelTemplate>
                    <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="*"/>
                            <ColumnDefinition Width="Auto"/>
                            <ColumnDefinition Width="auto"/>
                            <ColumnDefinition Width="auto"/>
                        </Grid.ColumnDefinitions>
                    </Grid>
                </ItemsPanelTemplate>
            </StatusBar.ItemsPanel>
            <StatusBarItem Grid.Column="1">
                <TextBlock Name="statusText"></TextBlock>
            </StatusBarItem>
            <StatusBarItem Grid.Column="2">
                <ProgressBar Name="statusPG" Width="80" Height="18" IsEnabled="False" />
            </StatusBarItem>
            <StatusBarItem Grid.Column="3">
                <Button Name="statusB" IsCancel="True" IsEnabled="False">Cancel</Button>
            </StatusBarItem>
        </StatusBar>
    </DockPanel>
</Window>

Answer 1

Your code runs a very tight loop, and in its center it calls ReportProgress ().

This means that your MessageQueue is loaded with requests for execution updates.

If you create some delay (Thread.Sleep (100)) in the Bgw stream, you will see that responsiveness improves.

A more practical solution is to move the report into an external loop. In your case:

for (int i = 1; i <= 30; i++)
{
    int percent = (i * 100) / 30;
    _worker.ReportProgress(percent);
    for(int j = 0; ....)
        ....
}

1 , : "if ((counter% 100) == 0)...`

- , 10 100 Reportprogress.

Answer 2

 if (current++ % onePercent == 0)
                    {
                         int percent = Convert.ToInt32(((decimal)current / (decimal)max) * 100);
                         this._worker.ReportProgress(percent, new WorkerUserState { current = current, max = max });                        
                    }

.

Answer 3

Your anonymous method for the ProgressChanged event will be run in the user interface thread. since you are reporting frequent progress, it will be queued by the dispatcher and will block the user interface.