c# - WPF how to access MainPage elements from Popup Page -

I am creating a WPF app that requires a numeric input from the user. I am using the navigation window and I An page is created in which there is a numeric keypad, the app requires numerical input more than once. Inspired by this, I want to put a popup inside a frame inside the page as follows:

  & Lt; Grid name = "main display" & gt; & Lt; Popup name = "popup dialog" placement target = "{bining elementname = an input box placement =" center "> gt; stackpayel & gt; frame source =" mynumpad.xaml "/> gt; & lt; button click = "OK_Outside_Click">   
 "Ok_Outside_Numpad"       
     code> button is clicked, the numpad disappears and the main page is reactivated. The code is as follows:  
  private Zero OK_Outside_Click (Object Sender, RoutedEventArgs e) {popupDialog.IsOpen = Wrong; mainDisplay. IsEnabled = true;}   
 Two questions:  
 
 
 Already a "OK" button  inside   MyNumpad.xaml . Is it possible to click  mainDisplay  and  popupDialog   Ok_Inside_Numpad  button? I  MyNumpad  Code> Can I pass the variable for the constructor?   
 
 How to obtain user numeric input when  gets out of MyNump ad ?    
 Thank you! Note that I'm new to WPF, not sure my view is any good any ideas are welcome!  
  
 
 
 The correct approach is  view  s (NavigationWindows and MyNumpad.xaml) Can be sent to  ViewModel  (or many view models). With data binding, you just set a false value to close the popup (since the popup's ison property is linked to that value). It does not matter where the control is from, because you do not have to manipulate the controls in your code.  
 But before reading that article and before learning about MVVM, you can make some changes to your code. It works.  
 Can not access the main page elements on the host page, because there is no reference to the men page on the host page. As you have thought, you can pass the menopp to the constructor of  MyNumpad  (in the code, and remember to modify the MyNumpad's constructor).  
  Public MainWindow () {InitializeComponent (); Mimeampad numpad = new MyNumpad (this); Frame1.Nagigate (numpad); }   
 Then you can access the mainpage elements from the pop-up page.  
 But clicking on the popup button is easy to add event handlers, because the event handler is defined in the main window, its main configuration has access to all the controls (Remember to delete the event handler set in MyNumpad.)  
  string strNumber; Public Manvindo () {Initialization (); MyNumpad numpad = New MyNumpad (); Numpad.button1.AddHandler (Button ClickClick Event, New Routing Documents Handler ((S, E) => Suppose User Input is a text box in the page to accept Stronmember = numpad.InputTextBox.Text; PopupDialog.IsOpen = false; MainDisplay.IsEnabled = true;}), false); Frame1.Nagigate (numpad); }