WinUI3: How to search and get control from loaded XAML file

Question

Hi,
In App.xaml.cs, I already loaded MainWindow.xaml from a persistent storage, such as 'C:\Projects\SamplePages\MainWindows.xaml' by using this codes:

My question is that: How can I find and get the NavigationView control from this window? Thank you.

Answer 1

With VisualTreeHelper
I use utility functions like :

    private DependencyObject FindChildElementByName(DependencyObject tree, string sName)  
    {  
        for (int i = 0; i < Microsoft.UI.Xaml.Media.VisualTreeHelper.GetChildrenCount(tree); i++)  
        {  
            DependencyObject child = Microsoft.UI.Xaml.Media.VisualTreeHelper.GetChild(tree, i);  
            if (child != null && ((FrameworkElement)child).Name == sName)  
                return child;  
            else  
            {  
                DependencyObject childInSubtree = FindChildElementByName(child, sName);  
                if (childInSubtree != null)  
                    return childInSubtree;  
            }  
        }  
        return null;  
    }