Win32API+WinRT+XamlなGUIを.NETやUWPなしで作成する（１）

<?xml version="1.0" encoding="UTF-8"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
    <application>
      <!-- Windows 10 -->
      <maxversiontested Id="10.0.18362.0"/>
      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
    </application>
  </compatibility>
</assembly>

#include "pch.h"

#include <windows.h>
#include <stdlib.h>
#include <string.h>

#include <winrt/Windows.Foundation.Collections.h>
#include <winrt/Windows.system.h>
#include <winrt/windows.ui.xaml.hosting.h>
#include <windows.ui.xaml.hosting.desktopwindowxamlsource.h>
#include <winrt/windows.ui.xaml.controls.h>
#include <winrt/Windows.ui.xaml.media.h>

using namespace winrt;
using namespace Windows::UI;
using namespace Windows::UI::Composition;
using namespace Windows::UI::Xaml::Hosting;
using namespace Windows::Foundation::Numerics;


// Microsoftのサンプルをそのままビルドすると
// TextOutでリンクエラーが出るのでこれらを追加しておく
#pragma comment(lib,"gdi32.lib")



LRESULT CALLBACK WindowProc(HWND, UINT, WPARAM, LPARAM);

HWND _hWnd;
HWND _childhWnd;
HINSTANCE _hInstance;


 

int CALLBACK WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPSTR lpCmdLine, _In_ int nCmdShow)
{
  _hInstance = hInstance;

  // The main window class name.
  const wchar_t szWindowClass[] = L"Win32DesktopApp";
  WNDCLASSEX windowClass = { };

  windowClass.cbSize = sizeof(WNDCLASSEX);
  windowClass.lpfnWndProc = WindowProc;
  windowClass.hInstance = hInstance;
  windowClass.lpszClassName = szWindowClass;
  windowClass.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);

  windowClass.hIconSm = LoadIcon(windowClass.hInstance, IDI_APPLICATION);

  if (RegisterClassEx(&windowClass) == NULL)
  {
    MessageBox(NULL, L"Windows registration failed!", L"Error", NULL);
    return 0;
  }

  _hWnd = CreateWindow(
    szWindowClass,
    L"Windows c++ Win32 Desktop App",
    WS_OVERLAPPEDWINDOW | WS_VISIBLE,
    CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
    NULL,
    NULL,
    hInstance,
    NULL
  );
  if (_hWnd == NULL)
  {
    MessageBox(NULL, L"Call to CreateWindow failed!", L"Error", NULL);
    return 0;
  }


  // Begin XAML Island section.

  // The call to winrt::init_apartment initializes COM; by default, in a multithreaded apartment.
  winrt::init_apartment(apartment_type::single_threaded);

  // Initialize the XAML framework's core window for the current thread.
  WindowsXamlManager winxamlmanager = WindowsXamlManager::InitializeForCurrentThread();

  // This DesktopWindowXamlSource is the object that enables a non-UWP desktop application 
  // to host WinRT XAML controls in any UI element that is associated with a window handle (HWND).
  DesktopWindowXamlSource desktopSource;

  // Get handle to the core window.
  auto interop = desktopSource.as<IDesktopWindowXamlSourceNative>();

  // Parent the DesktopWindowXamlSource object to the current window.
  check_hresult(interop->AttachToWindow(_hWnd));

  // This HWND will be the window handler for the XAML Island: A child window that contains XAML.  
  HWND hWndXamlIsland = nullptr;

  // Get the new child window's HWND. 
  interop->get_WindowHandle(&hWndXamlIsland);

  // Update the XAML Island window size because initially it is 0,0.
  SetWindowPos(hWndXamlIsland, 0, 200, 100, 800, 200, SWP_SHOWWINDOW);

  // Create the XAML content.
  Windows::UI::Xaml::Controls::StackPanel xamlContainer;
  xamlContainer.Background(Windows::UI::Xaml::Media::SolidColorBrush{ Windows::UI::Colors::LightGray() });

  Windows::UI::Xaml::Controls::TextBlock tb;
  tb.Text(L"Hello World from Xaml Islands!");
  tb.VerticalAlignment(Windows::UI::Xaml::VerticalAlignment::Center);
  tb.HorizontalAlignment(Windows::UI::Xaml::HorizontalAlignment::Center);
  tb.FontSize(48);

  xamlContainer.Children().Append(tb);
  xamlContainer.UpdateLayout();
  desktopSource.Content(xamlContainer);

  // End XAML Island section.

  ShowWindow(_hWnd, nCmdShow);
  UpdateWindow(_hWnd);

  //Message loop:
  MSG msg = { };
  while (GetMessage(&msg, NULL, 0, 0))
  {
    TranslateMessage(&msg);
    DispatchMessage(&msg);
  }

  return 0;
}

///////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////

LRESULT CALLBACK WindowProc(HWND hWnd, UINT messageCode, WPARAM wParam, LPARAM lParam)
{
  PAINTSTRUCT ps;
  HDC hdc;
  wchar_t greeting[] = L"Hello World in Win32!";
  RECT rcClient;

  switch (messageCode)
  {
  case WM_PAINT:
    if (hWnd == _hWnd)
    {
      hdc = BeginPaint(hWnd, &ps);
      TextOut(hdc, 300, 5, greeting, wcslen(greeting));
      EndPaint(hWnd, &ps);
    }
    break;
  case WM_DESTROY:
    PostQuitMessage(0);
    break;

    // Create main window
  case WM_CREATE:
    _childhWnd = CreateWindowEx(0, L"ChildWClass", NULL, WS_CHILD | WS_BORDER, 0, 0, 0, 0, hWnd, NULL, _hInstance, NULL);
    return 0;

    // Main window changed size
  case WM_SIZE:
    // Get the dimensions of the main window's client
    // area, and enumerate the child windows. Pass the
    // dimensions to the child windows during enumeration.
    GetClientRect(hWnd, &rcClient);
    MoveWindow(_childhWnd, 200, 200, 400, 500, TRUE);
    ShowWindow(_childhWnd, SW_SHOW);

    return 0;

    // Process other messages.

  default:
    return DefWindowProc(hWnd, messageCode, wParam, lParam);
    break;
  }

  return 0;
}