wpf working state

I have a grid in my application. After user selects some files in ofdialog application processes some calculations. While 开发者_StackOverflow中文版app is making calculations it looks like it is not responding. How to display some picture and make main window in black&white while calculating? Maybe make some dp in MainWindow a la "IsBusy" and bind a popup with picture to it?

How you implement this logic in yours apps?

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One easy way is to use the busy indicator from Extended WPF Toolkit:

Dowload the binaries and add project reference to WPFToolkit.Extended.dll.

Next add following namespace in your 'main window':

xmlns:ext="clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit.Extended"

Then add the busy indicator in the view (place it so that when shown, it will occupy the whole screen) Here my main window has two rows and I want the control to span on both rows. The control's IsBusy property is bound to a bool property in the view's data context.

<ext:BusyIndicator Grid.RowSpan="2" x:Name="busyIndicator" IsBusy="{Binding IsBusy}" />

The long lasting calculation should be processed in another thread so that it won't block the user interface. For threading you can use BackgroundWorker class.

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You should have the long running tasks in a seperate thread to avoid UI blocking. Here's one way you could achieve that:

Define background thread as below:

//Delegate that you could pass into the worker thread
public delegate void ProgressMonitor(string s);

//Call this to start background work
void StartLongRunningWork(ProgressMonitor mon)
{
    using (BackgroundWorker bgw = new BackgroundWorker())
    {
        bgw.DoWork             += WorkerThread;
        bgw.RunWorkerCompleted += WorkerThreadCompleted;
        bgw.RunWorkerAsync(mon);
    }
}

void WorkerThread(object sender, DoWorkEventArgs e)
{
    ProgressMonitor pm = (ProgressMonitor)e.Argument;
    WorkerActual(pm, <any other parameters>);
}

void WorkerActual(ProgressMonitor pm,<any other parameters>)
{
    ...
    pm("Doing x");
    Do long running task
    pm("Doing y");
    ...
}

//This function is called in case of Exception, Cancellation or successful completion
//of the background worker. Handle each event appropriately
void WorkerThreadCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    if (e.Error != null)
    {
        //Long running task threw an exception
    }
    else
        if (e.Cancelled)
        {
            //Long running task was cancelled
        }
        else
        {
            //Long running task was successfuly completed
        }
}

And Call it as below:

private void UpDateProgressLabel(string s)
{
    this.Dispatcher.BeginInvoke((Action)delegate
       {
           NotificationLabel.Content = s;
       });
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    StartLongRunningWork(UpDateProgressLabel);
}