Is it possible to programatically create a xaml page? - c++-winrt

Question

I might write no sense on the next lines:
I tried to derive a struct named mainpage from winrt::Windows::UI::Xaml::Controls::Page and pass it to winrt::xaml_typename<>(), in "<>" is mainpage.
It will be understandable when you look at the code:
Point number 1 "(1)" is the mainpage.h file, is very short.
Point number 2 "(2)" is the App.cpp file, it only has the necessary.
//(1) mainpage.h
#pragma once
#include "pch.h"
struct mainpage : winrt::Windows::UI::Xaml::Controls::Page
{
mainpage() {
winrt::Windows::UI::Xaml::Controls::Button thebutton = winrt::Windows::UI::Xaml::Controls::Button();
thebutton.Click([&](const IInspectable& sender, const winrt::Windows::UI::Xaml::RoutedEventArgs& event_arg)
{
thebutton.Content(winrt::box_value(L"Clicked"));
});
}
};
//(2) App.cpp
#include "pch.h"
#include "mainpage.h"
struct App : winrt::Windows::UI::Xaml::ApplicationT<App>
{
void OnLaunched(const winrt::Windows::ApplicationModel::Activation::LaunchActivatedEventArgs& event_arg)
{
winrt::Windows::UI::Xaml::Controls::Frame root_frame{ nullptr };
winrt::Windows::UI::Xaml::UIElement content = winrt::Windows::UI::Xaml::Window::Current().Content();
if (content)
{
root_frame = content.try_as<winrt::Windows::UI::Xaml::Controls::Frame>();
}
// Do not repeat app initialization when the Window already has content,
// just ensure that the window is active
if (root_frame == nullptr)
{
// Create a Frame to act as the navigation context and associate it with
// a SuspensionManager key
root_frame = winrt::Windows::UI::Xaml::Controls::Frame();
root_frame.NavigationFailed({ this, &App::OnNavigationFailed });
if (event_arg.PreviousExecutionState() == winrt::Windows::ApplicationModel::Activation::ApplicationExecutionState::Terminated)
{
// Restore the saved session state only when appropriate, scheduling the
// final launch steps after the restore is complete
}
if (event_arg.PrelaunchActivated() == false)
{
if (root_frame.Content() == nullptr)
{
// When the navigation stack isn't restored navigate to the first page,
// configuring the new page by passing required information as a navigation
// parameter
root_frame.Navigate(winrt::xaml_typename<mainpage>(), box_value(event_arg.Arguments()));
}
// Place the frame in the current Window
winrt::Windows::UI::Xaml::Window::Current().Content(root_frame);
// Ensure the current window is active
winrt::Windows::UI::Xaml::Window::Current().Activate();
}
}
else
{
if (event_arg.PrelaunchActivated() == false)
{
if (root_frame.Content() == nullptr)
{
// When the navigation stack isn't restored navigate to the first page,
// configuring the new page by passing required information as a navigation
// parameter
root_frame.Navigate(winrt::xaml_typename<mainpage>(), box_value(event_arg.Arguments()));
}
// Ensure the current window is active
winrt::Windows::UI::Xaml::Window::Current().Activate();
}
}
}
void App::OnNavigationFailed(const IInspectable&, const winrt::Windows::UI::Xaml::Navigation::NavigationFailedEventArgs& event_arg)
{
throw winrt::hresult_error(E_FAIL, winrt::hstring(L"Failed to load Page ") + event_arg.SourcePageType().Name);
}
};
int __stdcall wWinMain(HINSTANCE, HINSTANCE, PWSTR, int) {
winrt::Windows::UI::Xaml::Application::Start([](auto &&) { winrt::make<App>(); });
}
If it is not possible, how can I properly create a page?

Answer 1

It is simple if you have installed the CppWinRT VSIX. Then create a "View model" and edit the files. You shouldn't derive the struct from the winrt::Windows::UI::Xaml::Controls::Page class because winrt::xaml_typename<> needs a WinRT class in <>.