Thread calls between two windows?

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Hi! First question, long time reader!

I'm trying to get to grips with threaded apps but can't seem to get passed the second hurdle. The first I've managed - to launch a second window in a separate thread. However, it is no use if the first window cannot prod the second into doing things! And visa-versa.

In future, the idea is that one window is the main control which has lists and buttons and a scheduler maybe; the other monitors things but has it's own user interaction. The first for example changes what the second monitors; the second later reports back what it has monitored to the first to display and corrolate...

I have a window with two buttons - "Open Window" and "Close Window".

private void ButtonOpen_Click(object sender, RoutedEventArgs e)
{
	Thread tbr = new Thread(() =>
		{
		Window2 br = new Window2();
		br.Closed += (sender2, e2) => br.Dispatcher.InvokeShutdown();
		br.Show();
		System.Windows.Threading.Dispatcher.Run();
		});
	tbr.SetApartmentState(ApartmentState.STA);	//required for WPF
	tbr.Start();
	((Button)sender).IsEnabled = false;
}

private void ButtonClose_Click(object sender, RoutedEventArgs e)
{
//need to figure out how this works	
}

ButtonOpen_Click creates a thread and launches a new instanace of Window2 with UI message pump and has a gracefull exit when closed.

But, how do I invoke "this.close" in the second window via the first's ButtonClose_Click? Since the first is on a different thread? I guess if I can crack this, then the same principle can be used for anything I want to call via a button click on the first window to invoke something to happen in the second?

Thanks in advance for your help.

Posted 15-Jun-11 11:48am

NT986

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Sergey Alexandrovich Kryukov 15-Jun-11 18:26pm

Weird idea. Why doing so? You can perfectly do all multi-threading in WPF in one shared UI thread and multiple working thread using Dispatcher's Invoke/BeginInvoke....
My I know the idea?
--SA

Sergey Alexandrovich Kryukov 15-Jun-11 18:28pm

You should understand that Windows and threads are not directly related. You can use the same window in several threads (of cause, multiple windows in one thread). Also, one-windows UI is the best (a few modal windows would not hurt, very few). Why all that? Just for research?
--SA

2 solutions

Solution 1

Hello Dear
Some times a go i was working on a chat program . because a lot of client connect to server , it was necessary that server work on multiple thread , i had a lot of problem like you , bu finally i could solve my problem . there is a standard way to communicate between thread and controls in each thread , and it is 'Invoke' method which is one of methods of 'Control' class.

I guild you by one example :
I create a project with two forms : Form1 , Form2
Form1 has two button : BtnOpenForm , BtnCloseForm
when user clicks BtnOpenForm a new thread creates and in that thread create a new instance of Form2 then this new insatnce is shown
when user clicks BtnCloseForm this new instance will close

this is an abstract Sample not a complete one . but you can Communicate between any controls in any thread

Form1 :

C#

public delegate void DelegetCloseForm();
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    private Form2 F;
    private void BtnOpenForm_Click(object sender, EventArgs e)
    {
        System.Threading.Thread T = new System.Threading.Thread(delegate()
            {
                F = new Form2();
                F.ShowDialog();
            });
        T.Start();
    }
    private void BtnCloseForm_Click(object sender, EventArgs e)
    {
        this.F.Invoke(F.Dlg);
    }
}

Form2 :

C#

public DelegetCloseForm Dlg;
private void CloseForm()
{
    this.Close();
}
public Form2()
{
    InitializeComponent();
    Dlg = new DelegetCloseForm(this.CloseForm);
}

this is very simple , just need a little practice
if had problem comment me
Good luck

Posted 15-Jun-11 19:51pm

Reza Mansoori

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NT986 · Accepted Answer · 2011-06-15T21:26:00

Thanks Reza Mansoori615 for pointing the way! I'm extremely grateful. That's how I tried it originally, changed it, then tried random things getting more and more frustrated.

However, that's the Windows Forms way, not WPF... A bit more looking and I found a hint - in WPF, Invoke is called via the Dispatcher. So...

Window 1:

MSIL

public delegate void dWindow2Close(); //declare - outside window class
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private Window2 br;
    private void ButtonOpen_Click(object sender, RoutedEventArgs e)
    {
        Thread tbr = new Thread(() =>
                {
                    br = new Window2();
                    br.Closed += (sender2, e2) =>
                        br.Dispatcher.InvokeShutdown();
                    br.Show();
                    System.Windows.Threading.Dispatcher.Run();
                });
        tbr.SetApartmentState(ApartmentState.STA);  //required for WPF
        tbr.Start();
        ((Button)sender).IsEnabled = false;
    }

    private void ButtonClose_Click(object sender, RoutedEventArgs e)
    {
        br.Dispatcher.Invoke(br.Window2Close);
    }
}

Window 2

MSIL

public partial class Window2 : Window
{
    public dWindow2Close Window2Close;    //to instantiate

    public Window2()
    {
        InitializeComponent();
        Window2Close = new dWindow2Close(SecondWindowClose);
    }

    private void SecondWindowClose()
    {
        this.Close();
    }
}

For those who asked, I intend opening 5 to 10 browser windows to monitor live data in real time and collate to a central DB. Navigating the DOM is trivial so there is no actual work to offload to a background worker. However, when each browser starts running flash ads the workload is not trivial for one thread! And all my other CPU's stand idle while a single one is choking... Launching each browser in a seperately threaded window seems my only option.

Thanks again to those who read and replied!

Thread calls between two windows?

2 solutions

Solution 1

Solution 2

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