How is Navigation from ContentDialog to a different page in UWP which uses Template10 MVVM possible?

Question

LoginPageCD.xaml

<ContentDialog
x:Class="ScanWorx.ContentDialogs.LoginPageCD"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:ScanWorx.ContentDialogs"
xmlns:vm="using:ScanWorx.ViewModels"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
x:Name="LoginPageContentD"
SecondaryButtonText="close"
SecondaryButtonClick="LoginPageContentD_SecondaryButtonClick">

<ContentDialog.Resources>
    <Thickness x:Key="ContentDialogPadding">16,16,16,16</Thickness>
    <vm:LoginPageCDViewModel x:Key="CDViewModel"  />
</ContentDialog.Resources>

<!--  Content Dialog Title  -->
<ContentDialog.TitleTemplate>
    <DataTemplate >

        <TextBlock
            HEADER DATA FOR TEMPLATE/>

    </DataTemplate>
</ContentDialog.TitleTemplate>

<ContentControl x:Name="LoginPageContentControl" Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <ContentControl.ContentTemplate>
        <DataTemplate>
            <Grid Width="500" Height="500">
                <Grid.RowDefinitions>
                    <RowDefinition />
                    <RowDefinition />
                    <RowDefinition Height="1*" />
                </Grid.RowDefinitions>

                <ComboBox
                    x:Name="Combobox_Login_test"
                    Grid.Row="0"
                    Header="Combobox_Login.Header"
                    IsEditable="True"
                    ItemsSource = "{Binding UserNameList, Source = {StaticResource CDViewModel}}" 
                    Text="{Binding Name, Source = {StaticResource CDViewModel},FallbackValue=DesigntimeValue, Mode=TwoWay}"/>

                <PasswordBox
                    x:Name="PasswordBox_Login"
                    Grid.Row="1"
                    Header="PasswordBox_Login.Header"
                    Password="{Binding Passwort, Mode=TwoWay , Source= {StaticResource CDViewModel}}" />

                <Button
                    x:Name="Button_Login_Click"
                    Grid.Row="2"
                    Command="{Binding LoginButtonCommand, Mode=TwoWay, Source= {StaticResource CDViewModel}}"
                    Style="{ThemeResource AccentButtonStyle}"/>

            </Grid>
        </DataTemplate>
    </ContentControl.ContentTemplate>
</ContentControl>

LoginPageCD.xaml.cs <== Code behind

using ScanWorx.ViewModels;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.ApplicationModel.Resources;
using Template10.Mvvm;

namespace ScanWorx.ContentDialogs
{

public partial class LoginPageCD : ContentDialog
{

    public LoginPResult Result { get; set; }

    public static ResourceLoader dict;
    public LoginPageCD()
    {
        this.InitializeComponent();
        ViewModelBase viewModelBase = new LoginPageCDViewModel();
        this.DataContext = viewModelBase;
        dict = ResourceLoader.GetForCurrentView("Login");
        LoginPageCDViewModel LPVM = new LoginPageCDViewModel();
        LPVM.UpdateUserNameList();
    }


    private void LoginPageContentD_SecondaryButtonClick(ContentDialog sender, ContentDialogButtonClickEventArgs args)
    {
        Frame rootFrame = Window.Current.Content as Frame;
        rootFrame = new Frame();
        Window.Current.Content = rootFrame;
        rootFrame.Navigate(typeof(Views.LoginPage));

        LoginPageContentD.Hide();
       
    }

}
}

LoginPageCDViewModel.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.IO;
using System.Threading.Tasks;
using System.Xml;
using Template10.Mvvm;
using Template10.Services.NavigationService;
using Windows.ApplicationModel.Resources;
using Windows.Storage;
using Windows.Storage.Pickers;
using Windows.UI.Popups;
using Windows.UI.Xaml.Navigation;
using System.Linq;
using Windows.UI.Xaml;
using Template10.Utils;

namespace ScanWorx.ViewModels
{
class LoginPageCDViewModel : ViewModelBase
{
    public static ObservableCollection<string> _UserNameList = new ObservableCollection<string>();
    public ObservableCollection<string> UserNameList { get { return _UserNameList; } set { Set(ref _UserNameList, value); } }

    private string _Name = "";
    private string _Passwort = "";

    public RelayCommand LoginButtonCommand
    {
        get;
        private set;
    }

    public string Name { get { return _Name; } set { Set(ref _Name, value); } }
    public string Passwort { get { return _Passwort; } set { Set(ref _Passwort, value); } }


    public static ResourceLoader dict;

    public ObservableCollection<string> UpdateUserNameList()
    {
        try
        {
            **A FUNCTION TO UPDATE THE USER's LIST IN THE COMBOBOX**
            **USAGE: USED IN CODE BEHIND WHILE INITIALIZING THE CONTENT DIALOG**
        }
        catch
        {
            Debug.WriteLine("Catch Exeption:  LoginPage.xaml.cs     Invalid UserManagement.xml file");
        }
        return _UserNameList;
    }

    public LoginPageCDViewModel()
    {
        if (Windows.ApplicationModel.DesignMode.DesignModeEnabled)
        {
            Value = "Designtime value";
        }
        Services.SettingsServices.SettingsService.Instance.IsFullScreen = true;

        LoginButtonCommand = new RelayCommand(Button_Login_Click, () => true);

        dict = ResourceLoader.GetForCurrentView("Login");
    }
 
    public async void Button_Login_Click()
    {
        try
        {
                **ACTION: some code to check the username and password**

                loginPageCDViewModel.navigatetomain();        //<<<<// a function to navigate to main page which doesnt work     
                //NavigationService.Navigate(typeof(Views.MainPage));

        }
        catch
        {
            Debug.WriteLine("Catch Exeption:  LoginPageCDViewModel.cs     Button_Login_Click");
        }
    }

    public void navigatetomain()
    {
        Frame rootFrame = Window.Current.Content as Frame;
        rootFrame = new Frame();
        Window.Current.Content = rootFrame;
        rootFrame.Navigate(typeof(Views.MainPage));
        LoginPageContentD.Hide();

        //NavigationService.Navigate(typeof(Views.MainPage));

    }
}
}

• The above work is what I have tried. I also tried to navigate to the main page using NavigationService.Navigate(typeof(Views.MainPage)); but it is also not working.
• Any help is appreciated
• I am able to navigate to mainpage using the function navigatetomain() but the content dialog doesnt close even though i am trying to Hide(); and also after navigation I am not able to see my hamburger menu in my Mainpage its just a blank mainpage.

NOTE: The Hide(); in code behind for close button works perfect.

Answer 1

Instead of having a button of my own [Button_Login_click] I used the primarybuttonclick of contentdialog and using relaycommand declared in LoginPageCDViewModel.cs I Binded the primarybuttoncommand property to the relaycommand button declared in LoginPageCDViewModel.cs

So now my LoginPageCD.xaml looks like

<ContentDialog
    x:Class="ScanWorx.ContentDialogs.LoginPageCD"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:ScanWorx.ContentDialogs"
    xmlns:vm="using:ScanWorx.ViewModels"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    x:Name="LoginPageContentD"
    PrimaryButtonCommand="{x:Bind Path=vm:LoginPageViewModel.LoginButtonCommand }"
    PrimaryButtonText="Login"
    SecondaryButtonText="close"
    SecondaryButtonClick="LoginPageContentD_SecondaryButtonClick">
   .
   .
   .

and for navigation to the desired page I am making use of the result of the contentdialog box i.e I am calling the ShowAsync(); at the start of the app and after recognizing the primary click I am using NavigationService.Navigate(typeof(Views.MainPage)); to navigate.