Navigating with Button MVVM

Dec 16, 2013 at 7:21 AM
Hey Guys,

I could use your help one more time. Im trying to navigate from one page to another using a command bound to a button. I have found a way to do it in xaml BUT I need to pass a parameter to the new page/viewmodel.
Code behing is no solution for me, as we are working strictly with MVVM.
Any suggestions are welcome.
Dec 16, 2013 at 2:52 PM
You need to find the ModernFrame and set it's Source property to initiate the navigation. Finding the frame can be done with the VisualTreeHelper. If you're already passing a parameter through the Command, you'll need to find some other way to get a reference to the UserControl or ModernWindow; perhaps the constructor of the view model?
public class VisualHelper
{
    /// <summary>
    /// Finds a Child of a given item in the visual tree. 
    /// </summary>
    /// <param name="parent">A direct parent of the queried item.</param>
    /// <typeparam name="T">The type of the queried item.</typeparam>
    /// <param name="childName">x:Name or Name of child. </param>
    /// <returns>The first parent item that matches the submitted type parameter. 
    /// If no matching item can be found, 
    /// a null parent is being returned.</returns>
    public static T FindChild<T>(DependencyObject parent, string childName)
        where T : DependencyObject
    {
        // Confirm parent and childName are valid. 
        if (parent == null) return null;

        T foundChild = null;

        int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
        for (int i = 0; i < childrenCount; i++)
        {
            var child = VisualTreeHelper.GetChild(parent, i);
            // If the child is not of the request child type child
            T childType = child as T;
            if (childType == null)
            {
                // recursively drill down the tree
                foundChild = FindChild<T>(child, childName);

                // If the child is found, break so we do not overwrite the found child. 
                if (foundChild != null) break;
            }
            else if (!string.IsNullOrEmpty(childName))
            {
                var frameworkElement = child as FrameworkElement;
                // If the child's name is set for search
                if (frameworkElement != null && frameworkElement.Name == childName)
                {
                    // if the child's name is of the request name
                    foundChild = (T)child;
                    break;
                }
            }
            else
            {
                // child element found.
                foundChild = (T)child;
                break;
            }
        }

        return foundChild;
    }
}