Accessing MainWindow from another window

Question

I have created a new Window that opens up from the MainWindow. Upon clicking a button from this Window, the Window should close and at the same time trigger some event in MainWindow.

I thought this would be easy to implement but I don't know how to access MainWindow methods & fields from another Window...

Any help would be appreciated. Thanks! :)

possible duplicate of [Getting values from method from other form](http://stackoverflow.com/questions/2378511/getting-values-from-method-from-other-form) — H H, Apr 30 '11 at 09:08
I don't understand why this question is asked again and agian.. just do a search and you'll find 100's of them. — Shekhar_Pro, Apr 30 '11 at 09:31
The first exposure to class objects for many beginning programmers. — Hans Passant, Apr 30 '11 at 13:31

score 1 · Answer 1 · edited Jan 05 '14 at 15:34

1

That is the wrong way to do it... the child window should have a Closed event that you can register a handler for. If you really need to execute parent window functions from the child before it has closed then you can pass delegates in to the child when you open it.

edited Jan 05 '14 at 15:34

BenMorel

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answered Apr 30 '11 at 09:03

slugster

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score 0 · Answer 2 · answered Apr 30 '11 at 08:59

0

Use Application.MainWindow property

answered Apr 30 '11 at 08:59

Arsen Mkrtchyan

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score 0 · Answer 3 · answered Apr 30 '11 at 09:04

You dont need to do that in this way...

define in the child window an event like:

public event EventHandler Closing;

when you create this window in the main window subscribe to it:

Window1 wnd = new Window1();

wnd.Closing += new EventHandler(childClosing);

when closing the child window check if the event is subscribed and raise it:

if (Closing != null) {
  Closing(this, new EventArgs());
}

of course you need a childClosing method in the main window:

private void childClosing(object sender, EvenrArgs e) {
  /// do your work
}

If you need to pass some data back then you create a class that derives from EvenrArgs and use that instead. But you need a delegate different from Eventhandler like:

class ClosingArgs : EventArgs {
   // some property here
}

in the child window

delegate void ClosingEventHandler(object sender, ClosingArgs e);

and

public event ClosingEventHandler Closing;

cheers!

Hmmm...actually, if I wanted to pass some data back and used ClosingEventHandler instead of a normal EventHandler, would I also need to modify the line wnd.Closing += new EventHandler(childClosing)? — AshleyKang, Apr 30 '11 at 09:29

score 0 · Answer 4 · answered Apr 30 '11 at 09:09

This is quite simple since you want an action in the MainWindow to be triggered when the child window closes, simply register the close event :

// In the main window, whenever your start your child window (not in the constructor)
private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        var window = new Window();
        window.Closed += new EventHandler(window_Closed);
        window.ShowDialog();
    }

    void window_Closed(object sender, EventArgs e)
    {
        throw new NotImplementedException();
    }

Then the function window_Closed in the main window will be called when the child window is closed.

Accessing MainWindow from another window

4 Answers4