Open user control from user controls from the main window grid WPF

Dim Empl As New Employee
MainGrid.Children.Add(Empl)
Grid.SetRow(Empl, 1)

Public Class Employee
 Dim mw As New MainWindow
 Private Sub btnQuestionAdd_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles btnQuestionAdd.Click
 Dim Que As New QuestionAdd
 mw.MainGrid. Children.Add(Que)
 Grid.SetRow(Que, 2)
 Grid.SetColumn(Que, 1)
 End Sub
End Class

Dim Empl As New Employee 
MainGrid.Children.Add(Empl)
Grid.SetRow(Empl, 1)

Public Class Employee
 Dim mw As New MainWindow
 Private Sub btnQuestionAdd_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles btnQuestionAdd.Click
 Dim Que As New QuestionAdd
 mw.MainGrid.Children.Add( Que)
 Grid.SetRow(Que, 2)
 Grid.SetColumn(Que, 1)
 End Sub
End Class

Public Class Employee
 Dim mw As New MainWindow
 Private Sub btnQuestionAdd_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles btnQuestionAdd.Click
 Dim Que As New QuestionAdd
 mw.MainGrid.Children.Add(Que)
 Grid.SetRow(Que, 2)
 Grid.SetColumn(Que, 1 )
 mw.Show() '<---
 End Sub
End Class

Maybe first I will talk about my application.
For example, when an employee logs in to my application, he will load the “employee menu” :

Dim Empl As New Employee
MainGrid.Children.Add(Empl)
Grid.SetRow(Empl, 1)

This is from the Window_Loaded event. The menu is a user control, and I have several buttons to open and operate another user control. When I press the button “Question” for example:

Public Class Em ployee
 Dim mw As New MainWindow
 Private Sub btnQuestionAdd_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles btnQuestionAdd.Click
 Dim Que As New QuestionAdd
 mw .MainGrid.Children.Add(Que)
 Grid.SetRow(Que, 2)
 Grid.SetColumn(Que, 1)
 End Sub
End Class

< p>I don’t know why it is not loaded after button_click…..
Is it difficult to navigate the main window grid from other controls?

This is just a guess, because you didn’t provide much information, but I noticed that the following problem may be the culprit.

In your first code snippet, you seem to be creating employees from MainForm:

Dim Empl As New Employee
MainGrid.Children.Add(Empl) 
Grid.SetRow(Empl, 1)

Your following comment seems to confirm this hypothesis:

This is from Window_Loaded event. Menu is User Control, and there I have few buttons to open and operate another user controls. When I press for example button “Question”

However, in your Employee class , You are creating a brand new instance of MainWindow, and then adding data to it:

Public Class Employee
 Dim mw As New MainWindow
 Private Sub btnQuestionAdd_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles btnQuestionAdd.Click
 Dim Que As New QuestionAdd
 mw.MainGrid.Children.Add(Que)
 Grid.SetRow(Que, 2)
 Grid.SetColumn(Que, 1)
 End Sub
End Class

If this observation is correct, then I think you need to go back to the book and understand The concept of classes and instances.

You basically create a second form (hidden because you never explicitly displayed it), and then modify the second form instead of the original form. To prove this hypothesis , Please try Try adding the following lines of code:

Public Class Employee
 Dim mw As New MainWindow
 Private Sub btnQuestionAdd_Click(sender As System.Object, e As System. Windows.RoutedEventArgs) Handles btnQuestionAdd.Click
 Dim Que As New QuestionAdd
 mw.MainGrid.Children.Add(Que)
 Grid.SetRow(Que, 2)
 Grid.SetColumn (Que, 1)
 mw.Show() '<---
 End Sub
End Class

You may see a second form pop up, where Include all the changes you expect on the first form.

As for how to solve this problem, the easiest way is to add a parameter (“Sub New”) in the initializer, which accepts MainForm as Value. Then you can assign a value to a field or attribute (probably just your mw field) and continue your happy way. However, this will give you a headache, so it may be a good time to start learning more about software architecture , Especially the concept of separation of concerns.