// resource_study.cpp : 定义应用程序的入口点。
//

#include "framework.h"
#include "resource_study.h"
#include "windows.h"                      

#define MAX_LOADSTRING 100

// 全局变量:
HMENU hmenu, haddmenu; //定义菜单句柄
HDC hdc;
HDC hdcmem;
HBITMAP hBm;
BITMAP bm;
HINSTANCE hInst;                                // 当前实例
WCHAR szTitle[MAX_LOADSTRING];                  // 标题栏文本
WCHAR szWindowClass[MAX_LOADSTRING];            // 主窗口类名

// 此代码模块中包含的函数的前向声明:
ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    About(HWND, UINT, WPARAM, LPARAM);

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPWSTR    lpCmdLine,
                     _In_ int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // TODO: 在此处放置代码。

    // 初始化全局字符串
    LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadStringW(hInstance, IDC_RESOURCESTUDY, szWindowClass, MAX_LOADSTRING);
    MyRegisterClass(hInstance);

    // 执行应用程序初始化:
    if (!InitInstance (hInstance, nCmdShow))
    {
        return FALSE;
    }

    HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_RESOURCESTUDY));

    MSG msg;

    // 主消息循环:
    while (GetMessage(&msg, nullptr, 0, 0))
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return (int) msg.wParam;
}

//
//  函数: MyRegisterClass()
//
//  目标: 注册窗口类。
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEXW wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);

    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = WndProc;
    wcex.cbClsExtra     = 0;
    wcex.cbWndExtra     = 0;
    wcex.hInstance      = hInstance;
    wcex.hIcon          = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_RESOURCESTUDY));
    wcex.hCursor        = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName   = MAKEINTRESOURCEW(IDC_RESOURCESTUDY);
    wcex.lpszClassName  = szWindowClass;
    wcex.hIconSm        = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    return RegisterClassExW(&wcex);
}

//
//   函数: InitInstance(HINSTANCE, int)
//
//   目标: 保存实例句柄并创建主窗口
//
//   注释:
//
//        在此函数中，我们在全局变量中保存实例句柄并
//        创建和显示主程序窗口。
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   hInst = hInstance; // 将实例句柄存储在全局变量中

   HWND hWnd = CreateWindowW(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, nullptr, nullptr, hInstance, nullptr);

   if (!hWnd)
   {
      return FALSE;
   }

   hBm = LoadBitmap(hInstance, MAKEINTRESOURCE(IDB_BITMAP2));//加载位图IDB_BITMAP2  (位图名称为IDB_BITMAP2)
   GetObject(hBm, sizeof(BITMAP), (LPVOID)& bm);//获取位图尺寸
   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);

   return TRUE;
}

//
//  函数: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  目标: 处理主窗口的消息。
//
//  WM_COMMAND  - 处理应用程序菜单
//  WM_PAINT    - 绘制主窗口
//  WM_DESTROY  - 发送退出消息并返回
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    //位图
    case WM_CREATE:
        hdc = GetDC(hWnd);      //获取设备环境句柄
        hdcmem = CreateCompatibleDC(hdc);//内存设备环境句柄
        ReleaseDC(hWnd, hdc);       //释放设备环境句柄
    case WM_COMMAND:
        {
            int wmId = LOWORD(wParam);
            // 分析菜单选择:
            switch (wmId)
            {
            case IDM_ADDMENU:       //在主菜单中添加弹出式菜单
                hmenu = GetMenu(hWnd);      //获取主菜单句柄
                haddmenu = CreateMenu();        //动态创建菜单
                //在创建的菜单中增加菜单项
                AppendMenu(haddmenu, MF_ENABLED, IDM_qiuhe, L"求和");
                AppendMenu(haddmenu, MF_ENABLED, IDM_fangcha, L"方差");
                AppendMenu(haddmenu, MF_ENABLED, IDM_pinjunzhi, L"平均值");
                AppendMenu(haddmenu, MF_ENABLED, IDM_junfanggen, L"均方根");
                //将创建的弹出式菜单插入主菜单中
                InsertMenu(hmenu, 2, MF_POPUP | MF_BYPOSITION,
                    (UINT)haddmenu, L"统计计算(&C)");
                //相应改变菜单中有关绘图统计计算菜单项的属性
                EnableMenuItem(hmenu, IDM_ADDMENU, MF_GRAYED);
                EnableMenuItem(hmenu, IDM_DELMENU, MF_ENABLED);
                DrawMenuBar(hWnd);      //重新显示窗口菜单
                break;
            case IDM_DELMENU:
                DeleteMenu(hmenu, 2, MF_BYPOSITION);    //删除统计计算菜单项
                //相应改变“文件”菜单中有关统计计算菜单项的属性
                EnableMenuItem(hmenu, IDM_ADDMENU, MF_ENABLED);
                EnableMenuItem(hmenu, IDM_DELMENU, MF_GRAYED);
                DrawMenuBar(hWnd);          //重新显示窗口菜单
                break;

            case IDM_ABOUT:
                DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
                break;
            case IDM_EXIT:
                DestroyWindow(hWnd);
                break;
            default:
                return DefWindowProc(hWnd, message, wParam, lParam);
            }
        }
        break;
    case WM_PAINT:
        {
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hWnd, &ps);
            // TODO: 在此处添加使用 hdc 的任何绘图代码...
            SelectObject(hdcmem, hBm);//将位图选入内存设备环境
            BitBlt(hdc, 180, 80, 50, 50, hdcmem, 0, 0, SRCCOPY);//调用函数BitBlt将内存设备中的位图复制到设备环境中
            EndPaint(hWnd, &ps);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

// “关于”框的消息处理程序。
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    UNREFERENCED_PARAMETER(lParam);
    switch (message)
    {
    case WM_INITDIALOG:
        return (INT_PTR)TRUE;

    case WM_COMMAND:
        if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
        {
            EndDialog(hDlg, LOWORD(wParam));
            return (INT_PTR)TRUE;
        }
        break;
    }
    return (INT_PTR)FALSE;
}