MouseClicks reaching back window WPF

I have created a sort of "processing" dialogbox which displays the progess of a certain process.It contains one progressbar and one Label. Here is the code:

public class ProcessingDialog
    {
        FrontWindow win;
        public ProcessingDialog(int min, int max, string initialMessage,string title, bool isContineous)
        {
            Thread th= new Thread(new ThreadStart(delegate()
            {
                win = new FrontWindow();
                win.Title = title;
                if (isContineous == false)
                {
                    win.ProgressBarProgress.Minimum = min;
                    win.ProgressBarProgress.Maximum = max;
                }
                else
                    win.ProgressBarProgress.IsIndeterminate = true;

                win.LabelStatus.Content = initialMessage;
                win.ShowInTaskbar = false;
                win.Topmost = true;
                win.ShowDialog();
            }
            ));
            th.SetApartmentState(ApartmentState.STA);
            th.Start();
        }


        public void Increment(int margin)
        {
            win.Dispatcher.Invoke(new ThreadStart(delegate { win.ProgressBarProgress.Value+=margin; }), null); ;
        }

        public void Reset()
        {
            win.Dispatcher.Invoke(new ThreadStart(delegate { win.ProgressBarProgress.Value=0; }), null); ;
        }

        public void ChangeMessage(string message)
        {
            win.Dispatcher.Invoke(new ThreadStart(delegate { win.LabelStatus.Content=message; }), null); ;
        }


        public void Close()
        {
            win.Dispatcher.Invoke(new ThreadStart(delegate { win.Close(); }), null); ;
        }
    }

This is the markup for FrontWindow:

<Window x:Class="WpfApplicationUnleashed.FrontWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="FrontWindow" Height="165" Width="300" WindowStyle="ThreeDBorderWindow" WindowStartupLocation="CenterOwner" ResizeMode="NoResize">
    <DockPanel>
        <ProgressBar x:FieldModifier="public" x:Name="ProgressBarProgress" Height="15" Margin="20" DockPanel.Dock="Top" VerticalAlignment="Top"></ProgressBar>
        <Label x:FieldModifier="public" x:Name="LabelStatus" Margin="10" VerticalAlignment="Top" HorizontalAlignment="Left" DockPanel.Dock="Bottom"></Label>
    </DockPanel>
</Window>

And here is the Window from where I show the dialogbox.It just cantains one buttons whose click event is this:

   private void button1_Click(object sender, RoutedEventArgs e)
        {
            ProcessingDialog pd = new ProcessingDialog(0, 10, "Starting", "Processing", false);
            Thread.Sleep(1000);

            pd.ChangeMessage("Step 1");
            pd.Increment(1);
            Thread.Sleep(1000);

            pd.ChangeMessage("Step 2");
            pd.Increment(1);
            Thread.Sleep(1000);开发者_开发知识库

            pd.ChangeMessage("Step 3");
            pd.Increment(1);
            Thread.Sleep(1000);


            pd.ChangeMessage("Step 4");
            pd.Increment(1);
            Thread.Sleep(1000);


            pd.ChangeMessage("Step 5");
            pd.Increment(1);
            Thread.Sleep(1000);


            pd.ChangeMessage("Step 6");
            pd.Increment(1);
            Thread.Sleep(1000);


            pd.ChangeMessage("Step 7");
            pd.Increment(1);
            Thread.Sleep(1000);


            pd.ChangeMessage("Step 8");
            pd.Increment(1);
            Thread.Sleep(1000);


            pd.ChangeMessage("Step 9");
            pd.Increment(1);
            Thread.Sleep(1000);


            pd.ChangeMessage("Step 10");
            pd.Increment(1);
            Thread.Sleep(1000);

            pd.Close();


        }

The problem is that when it's being shown, if i click the button again, when the dialogbox is closed, it opens again. I mean it does not get clicked because it's Modal, but it just queues up and when the dialogbox is closed, it gets clicked.

How can I prevent this from happening?

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Maybe bind a command to the button and write a CanExecute method which prevents the command from being executed if it is already in progress.

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If the back window is not meant to be used while the front window is open, I would set an event on the frontwindow's loaded to disable the back window, and on close, enable the back window.