User Defined constructor with ViewModel injected not firing when using RadTransitionControl

[Jinish]

Hello,

I am having some trouble while using the RadTransition control. The way i am using it is below:

<UserControl.Resources>
       <Style x:Key="TransitionFrameStyle"
               TargetType="sdk:Frame">
            <Setter Property="Background"
                    Value="Transparent" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="sdk:Frame">
                        <Border CornerRadius="5">
                            <Grid Background="{TemplateBinding Background}">
                                <telerik:RadTransitionControl x:Name="PART_FrameCP"
                                                              Content="{TemplateBinding Content}"
                                                              ContentTemplate="{TemplateBinding ContentTemplate}">
                                    <telerik:RadTransitionControl.Transition>
                                        <TransitionEffects:SlideAndZoomTransition MinAlpha="0.1"
                                                                                  MinZoom="0.9"
                                                                                  SlideDirection="LeftToRight"
                                                                                  StartSlideAt="0.25" />
                                    </telerik:RadTransitionControl.Transition>
                                </telerik:RadTransitionControl>
                                <Border BorderBrush="{TemplateBinding BorderBrush}"
                                        BorderThickness="{TemplateBinding BorderThickness}"
                                        Padding="{TemplateBinding Padding}" />
                            </Grid>
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
</UserControl.Resources>

Then using a frame control as below on the page:

<sdk:Frame Style="{StaticResource TransitionFrameStyle}"
                           Grid.Row="1"
                           NavigationFailed="Frame_NavigationFailed"
                           Source="{Binding Path=SelectedPage.PageUri}" />

Then in the Viewmodel for this page:

private readonly ObservableCollection<FramePage> pages;

public UserManagementSummaryViewModel(IRegionManager regionManager)
        {
            if (regionManager == null)
            {
                throw new ArgumentNullException("regionManager");
            }

            this.regionManager = regionManager;
            this.BackCommand = new DelegateCommand(this.NavigateToMainScreen);
            this.RefreshCommand = new DelegateCommand(this.RefreshUserPanel);
            this.ShowIconViewCommand = new DelegateCommand(this.ShowIconView);
            this.ShowListViewCommand = new DelegateCommand(this.ShowListView);

            this.pages = new ObservableCollection<FramePage>();
            pages.Add(new FramePage("Icon View", "/XYZ.UserManagementModule;component/Views/UserIconView.xaml"));
            pages.Add(new FramePage("List View", "/XYZ.UserManagementModule;component/Views/UserListView.xaml"));

            //// Set the default view to the Icons View page
            this.SelectedPage = this.pages[0];
        }

/// <summary>
        /// Gets or sets the selected page to display in the frame
        /// </summary>
        public FramePage SelectedPage
        {
            get
            {
                return GetProperty(() => this.SelectedPage);
            }

            set
            {
                SetProperty(() => this.SelectedPage, value);
            }
        }
        /// <summary>
        /// Gets the pages collection that can be displayed in the transition frame
        /// </summary>
        public ObservableCollection<FramePage> Pages
        {
            get
            {
                return this.pages;
            }
        }

/// <summary>
        /// Shows the Icon view page in the transition frame
        /// </summary>
        private void ShowIconView()
        {
            this.SelectedPage = this.pages[0];
        }

        /// <summary>
        /// Shows the List view page in the transition frame
        /// </summary>
        private void ShowListView()
        {
            this.SelectedPage = this.pages[1];
        }

Now i can navigate to the UserIconView and UserListView pages, thats nto a problem. The problem is that when i transition to any of these pages, in the code-behind, i have 2 constructors defined like this:

/// <summary>
        /// Initializes a new instance of the <see cref="UserListView"/> class.
        /// </summary>
        public UserListView()
        {
            this.InitializeComponent();
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="UserListView"/> class.
        /// </summary>
        /// <param name="userManagementViewModel">View model for <see cref="UserListView"/></param>
        public UserListView(UserManagementViewModel userManagementViewModel)
            : this()
        {
            this.DataContext = userManagementViewModel;
        }

The problem is that it only hits the Default constructor, the second user defined constructor is not fired at all, so basically i am not able to access my view model for these views.

Any help would be appreciated.

[Valeri Hristov]

Hi Jinish,

Are you able to get the correct behavior if you replace the RadTransitionControl with a ContentControl?

Greetings,
Valeri Hristov
the Telerik team

[Jinish]

Hi Valeri,

Yes, the problem apparently seems also with a ContentControl. Will need to dig a bit more into it.

[Jinish]

Solved the problem by making the Frame a Prism region and using the RegionManager's "RequestNavigate" method to navigate to the view. That seems to work fine, although, still couldnt figure out what was wrong in the original approach.