Issue demonstrated

SecondWndowIssueTest_v01.Core/Helpers/Json.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Threading.Tasks;
+
+using Newtonsoft.Json;
+
+namespace SecondWndowIssueTest_v01.Core.Helpers
+{
+    public static class Json
+    {
+        public static async Task<T> ToObjectAsync<T>(string value)
+        {
+            return await Task.Run<T>(() =>
+            {
+                return JsonConvert.DeserializeObject<T>(value);
+            });
+        }
+
+        public static async Task<string> StringifyAsync(object value)
+        {
+            return await Task.Run<string>(() =>
+            {
+                return JsonConvert.SerializeObject(value);
+            });
+        }
+    }
+}

SecondWndowIssueTest_v01.Core/Helpers/Singleton.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Concurrent;
+
+namespace SecondWndowIssueTest_v01.Core.Helpers
+{
+    public static class Singleton<T>
+        where T : new()
+    {
+        private static ConcurrentDictionary<Type, T> _instances = new ConcurrentDictionary<Type, T>();
+
+        public static T Instance
+        {
+            get
+            {
+                return _instances.GetOrAdd(typeof(T), (t) => new T());
+            }
+        }
+    }
+}

SecondWndowIssueTest_v01.Core/SecondWndowIssueTest_v01.Core.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <RootNamespace>SecondWndowIssueTest_v01.Core</RootNamespace>
+  </PropertyGroup>
+
+   <ItemGroup>
+    <Folder Include="Models\" />
+  </ItemGroup>
+
+   <ItemGroup>
+     <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
+   </ItemGroup>
+</Project>

SecondWndowIssueTest_v01.Core/readme.txt

@@ -0,0 +1,2 @@
+This core project is a .net standard project.
+It's a great place to put all your logic that is not platform dependent (e.g. model/helper classes) so they can be reused.

SecondWndowIssueTest_v01.sln

@@ -0,0 +1,77 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.28307.1145
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SecondWndowIssueTest_v01", "SecondWndowIssueTest_v01\SecondWndowIssueTest_v01.csproj", "{B5F40F5B-86C2-4791-8E1A-314F97B3F621}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SecondWndowIssueTest_v01.Core", "SecondWndowIssueTest_v01.Core\SecondWndowIssueTest_v01.Core.csproj", "{BA5DEF64-AC57-443B-A478-19C971323A5F}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Debug|ARM = Debug|ARM
+		Debug|ARM64 = Debug|ARM64
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|Any CPU = Release|Any CPU
+		Release|ARM = Release|ARM
+		Release|ARM64 = Release|ARM64
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|Any CPU.ActiveCfg = Debug|x86
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|ARM.ActiveCfg = Debug|ARM
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|ARM.Build.0 = Debug|ARM
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|ARM.Deploy.0 = Debug|ARM
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|ARM64.ActiveCfg = Debug|ARM64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|ARM64.Build.0 = Debug|ARM64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|ARM64.Deploy.0 = Debug|ARM64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|x64.ActiveCfg = Debug|x64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|x64.Build.0 = Debug|x64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|x64.Deploy.0 = Debug|x64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|x86.ActiveCfg = Debug|x86
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|x86.Build.0 = Debug|x86
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Debug|x86.Deploy.0 = Debug|x86
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|Any CPU.ActiveCfg = Release|x86
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|ARM.ActiveCfg = Release|ARM
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|ARM.Build.0 = Release|ARM
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|ARM.Deploy.0 = Release|ARM
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|ARM64.ActiveCfg = Release|ARM64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|ARM64.Build.0 = Release|ARM64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|ARM64.Deploy.0 = Release|ARM64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|x64.ActiveCfg = Release|x64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|x64.Build.0 = Release|x64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|x64.Deploy.0 = Release|x64
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|x86.ActiveCfg = Release|x86
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|x86.Build.0 = Release|x86
+		{B5F40F5B-86C2-4791-8E1A-314F97B3F621}.Release|x86.Deploy.0 = Release|x86
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Debug|ARM.Build.0 = Debug|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Debug|ARM64.ActiveCfg = Debug|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Debug|ARM64.Build.0 = Debug|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Debug|x64.Build.0 = Debug|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Debug|x86.Build.0 = Debug|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Release|ARM.ActiveCfg = Release|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Release|ARM.Build.0 = Release|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Release|ARM64.ActiveCfg = Release|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Release|ARM64.Build.0 = Release|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Release|x64.ActiveCfg = Release|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Release|x64.Build.0 = Release|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Release|x86.ActiveCfg = Release|Any CPU
+		{BA5DEF64-AC57-443B-A478-19C971323A5F}.Release|x86.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {A71A1292-B997-4A37-BC04-BD690BADB880}
+	EndGlobalSection
+EndGlobal

SecondWndowIssueTest_v01/.editorconfig

@@ -0,0 +1,11 @@
+# top-most EditorConfig file
+root = true
+
+[*]
+end_of_line = crlf
+
+[*.{cs,xaml}]
+indent_style = space
+indent_size = 4
+trim_trailing_whitespace = true
+insert_final_newline = true

SecondWndowIssueTest_v01/Activation/ActivationHandler.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Threading.Tasks;
+
+namespace SecondWndowIssueTest_v01.Activation
+{
+    // For more information on understanding and extending activation flow see
+    // https://github.com/Microsoft/WindowsTemplateStudio/blob/master/docs/UWP/activation.md
+    internal abstract class ActivationHandler
+    {
+        public abstract bool CanHandle(object args);
+
+        public abstract Task HandleAsync(object args);
+    }
+
+    // Extend this class to implement new ActivationHandlers
+    internal abstract class ActivationHandler<T> : ActivationHandler
+        where T : class
+    {
+        // Override this method to add the activation logic in your activation handler
+        protected abstract Task HandleInternalAsync(T args);
+
+        public override async Task HandleAsync(object args)
+        {
+            await HandleInternalAsync(args as T);
+        }
+
+        public override bool CanHandle(object args)
+        {
+            // CanHandle checks the args is of type you have configured
+            return args is T && CanHandleInternal(args as T);
+        }
+
+        // You can override this method to add extra validation on activation args
+        // to determine if your ActivationHandler should handle this activation args
+        protected virtual bool CanHandleInternal(T args)
+        {
+            return true;
+        }
+    }
+}

SecondWndowIssueTest_v01/Activation/DefaultActivationHandler.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Threading.Tasks;
+
+using SecondWndowIssueTest_v01.Services;
+
+using Windows.ApplicationModel.Activation;
+
+namespace SecondWndowIssueTest_v01.Activation
+{
+    internal class DefaultActivationHandler : ActivationHandler<IActivatedEventArgs>
+    {
+        private readonly Type _navElement;
+
+        public DefaultActivationHandler(Type navElement)
+        {
+            _navElement = navElement;
+        }
+
+        protected override async Task HandleInternalAsync(IActivatedEventArgs args)
+        {
+            // When the navigation stack isn't restored, navigate to the first page and configure
+            // the new page by passing required information in the navigation parameter
+            object arguments = null;
+            if (args is LaunchActivatedEventArgs launchArgs)
+            {
+                arguments = launchArgs.Arguments;
+            }
+
+            NavigationService.Navigate(_navElement, arguments);
+            await Task.CompletedTask;
+        }
+
+        protected override bool CanHandleInternal(IActivatedEventArgs args)
+        {
+            // None of the ActivationHandlers has handled the app activation
+            return NavigationService.Frame.Content == null && _navElement != null;
+        }
+    }
+}

SecondWndowIssueTest_v01/App.xaml

@@ -0,0 +1,19 @@
+<Application
+    x:Class="SecondWndowIssueTest_v01.App"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    >
+
+    <Application.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="/Styles/_Colors.xaml" />
+                <ResourceDictionary Source="/Styles/_FontSizes.xaml" />
+                <ResourceDictionary Source="/Styles/_Thickness.xaml" />
+
+                <ResourceDictionary Source="/Styles/TextBlock.xaml" />
+                <ResourceDictionary Source="/Styles/Page.xaml"/>
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </Application.Resources>
+</Application>

SecondWndowIssueTest_v01/App.xaml.cs

@@ -0,0 +1,45 @@
+using System;
+
+using SecondWndowIssueTest_v01.Services;
+
+using Windows.ApplicationModel.Activation;
+using Windows.UI.Xaml;
+
+namespace SecondWndowIssueTest_v01
+{
+    public sealed partial class App : Application
+    {
+        private Lazy<ActivationService> _activationService;
+
+        private ActivationService ActivationService
+        {
+            get { return _activationService.Value; }
+        }
+
+        public App()
+        {
+            InitializeComponent();
+
+            // Deferred execution until used. Check https://msdn.microsoft.com/library/dd642331(v=vs.110).aspx for further info on Lazy<T> class.
+            _activationService = new Lazy<ActivationService>(CreateActivationService);
+        }
+
+        protected override async void OnLaunched(LaunchActivatedEventArgs args)
+        {
+            if (!args.PrelaunchActivated)
+            {
+                await ActivationService.ActivateAsync(args);
+            }
+        }
+
+        protected override async void OnActivated(IActivatedEventArgs args)
+        {
+            await ActivationService.ActivateAsync(args);
+        }
+
+        private ActivationService CreateActivationService()
+        {
+            return new ActivationService(this, typeof(Views.BlankPage));
+        }
+    }
+}

SecondWndowIssueTest_v01/Helpers/ResourceExtensions.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Runtime.InteropServices;
+
+using Windows.ApplicationModel.Resources;
+
+namespace SecondWndowIssueTest_v01.Helpers
+{
+    internal static class ResourceExtensions
+    {
+        private static ResourceLoader _resLoader = new ResourceLoader();
+
+        public static string GetLocalized(this string resourceKey)
+        {
+            return _resLoader.GetString(resourceKey);
+        }
+    }
+}