Cannot access control items after switching windows in wpf

Question

Sorry about the title but I don't really know how to word the problem. Basically, I have a log in screen which comes up when you start the program. After the user logs in successfully, the current window is switched with

MainWindow obj = new MainWindow(userNameTextBox.Text);
App.Current.MainWindow = obj;
obj.Show(); //after login Redirect to second window  
this.Close();//after login hide the  Login window

I then try to fill a datagrid on the next window but get this error.

Object reference not set to an instance of an object.

I have tried just setting the text in a label and get the same error. When I have tried setting the text in a label in the login.xml.cs code (so after the this.close line) it works using this line

obj.label.Content = "test";

Why can I not access the wpf controls in the current window?

Call `InitializeComponents()` http://stackoverflow.com/questions/245825/what-does-initializecomponent-do-and-how-does-it-work-in-wpf — Khalil Khalaf, Apr 26 '16 at 23:42
Thanks. I was calling the method that used components before InitializeComponents() in the constructor. — Matt Key, Apr 27 '16 at 00:09
Glad it helped. Please mark/rate my answer if it answers your question :) — Khalil Khalaf, Apr 27 '16 at 00:12

score 0 · Accepted Answer · edited May 23 '17 at 12:31

0

You need to make sure that you are calling InitializeComponents() for your WPF before your method that is using the componenets.

Helpful Referenece: What does InitializeComponent() do, and how does it work in WPF?

edited May 23 '17 at 12:31

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answered Apr 27 '16 at 00:11

Khalil Khalaf

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Cannot access control items after switching windows in wpf

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