Windows程序设计---在空白框内实现点击效果

// 3.cpp : 定义应用程序的入口点。
//

#include "framework.h"
#include "3.h"

#define MAX_LOADSTRING 100

// 全局变量:
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_MY3, 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_MY3));

    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_MY3));
    wcex.hCursor        = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName   = MAKEINTRESOURCEW(IDC_MY3);
    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;
   }

   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 onLButtonDown(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    //MessageBox(hWnd, _T("是否进入"), _T("欢迎来到该界面"), MB_OK);
    char* str = (char*)"Hello";
    HDC hdc = GetDC(hWnd);
    TextOut(hdc, LOWORD(lParam), HIWORD(lParam), str, strlen(str));
    return 0;
}
LRESULT onLButtonUp(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    //MessageBox(hWnd, _T("是否进入"), _T("欢迎来到该界面"), MB_OK);
    char* str = (char*)"12345";
    HDC hdc = GetDC(hWnd);
    TextOut(hdc, LOWORD(lParam), HIWORD(lParam), str, strlen(str));
    return 0;
}
LRESULT OnCommand(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    int wmId = LOWORD(wParam);
    // 分析菜单选择:
    switch (wmId)
    {
    case IDM_ABOUT:
        DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
        break;
    case IDM_EXIT:
        DestroyWindow(hWnd);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}
LRESULT OnPaint(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hWnd, &ps);
        // TODO: 在此处添加使用 hdc 的任何绘图代码...
        EndPaint(hWnd, &ps);
         return 0;
}
LRESULT OnDestroy(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    PostQuitMessage(0);
    return 0;
}
struct MSG_ENIRY
{
    UINT nMessage;
    LRESULT(*pfn)(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
};
struct MSG_ENIRY msgEntry[] = {
    WM_LBUTTONDOWN,onLButtonDown,
    WM_LBUTTONUP,onLButtonUp,
    WM_COMMAND,OnCommand,
    WM_PAINT,OnPaint,
    WM_DESTROY,OnDestroy,
};
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    int nSize = sizeof(msgEntry) / sizeof(msgEntry[0]);
    for (int i = 0; i < nSize; i++) {
        if (msgEntry[i].nMessage == message) {
            (*msgEntry[i].pfn)(hWnd, message, wParam, lParam);
        }
    }
    return DefWindowProc(hWnd, message, wParam, lParam);
    /*switch (message)
    {
    case WM_LBUTTONDOWN:
        onLButtonDown(hWnd, message, wParam, lParam);
        break;
    case WM_COMMAND:
        OnCommand(hWnd, message, wParam, lParam);
        break;
    case WM_PAINT:
        OnPaint(hWnd, message, wParam, lParam);
        break;
    case WM_DESTROY:
        OnDestroy(hWnd, message, wParam, lParam);
        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;
}

代码改进之处：

1. 两种方式改变WndProc函数内部结构。

struct MSG_ENIRY
{
    UINT nMessage;
    LRESULT(*pfn)(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
};
struct MSG_ENIRY msgEntry[] = {
    WM_LBUTTONDOWN,onLButtonDown,
    WM_LBUTTONUP,onLButtonUp,
    WM_COMMAND,OnCommand,
    WM_PAINT,OnPaint,
    WM_DESTROY,OnDestroy,
};
int nSize = sizeof(msgEntry) / sizeof(msgEntry[0]);
    for (int i = 0; i < nSize; i++) {
        if (msgEntry[i].nMessage == message) {
            (*msgEntry[i].pfn)(hWnd, message, wParam, lParam);
        }
    }
return DefWindowProc(hWnd, message, wParam, lParam);

switch (message)
    {
    case WM_LBUTTONDOWN:
        onLButtonDown(hWnd, message, wParam, lParam);
        break;
    case WM_COMMAND:
        OnCommand(hWnd, message, wParam, lParam);
        break;
    case WM_PAINT:
        OnPaint(hWnd, message, wParam, lParam);
        break;
    case WM_DESTROY:
        OnDestroy(hWnd, message, wParam, lParam);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
    }

1. 采用调用内部函数的方式，将内部函数放到外面去。

LRESULT onLButtonDown(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    //MessageBox(hWnd, _T("是否进入"), _T("欢迎来到该界面"), MB_OK);
    char* str = (char*)"Hello";
    HDC hdc = GetDC(hWnd);
    TextOut(hdc, LOWORD(lParam), HIWORD(lParam), str, strlen(str));
    return 0;
}
LRESULT onLButtonUp(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    //MessageBox(hWnd, _T("是否进入"), _T("欢迎来到该界面"), MB_OK);
    char* str = (char*)"12345";
    HDC hdc = GetDC(hWnd);
    TextOut(hdc, LOWORD(lParam), HIWORD(lParam), str, strlen(str));
    return 0;
}
LRESULT OnCommand(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    int wmId = LOWORD(wParam);
    // 分析菜单选择:
    switch (wmId)
    {
    case IDM_ABOUT:
        DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
        break;
    case IDM_EXIT:
        DestroyWindow(hWnd);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}
LRESULT OnPaint(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hWnd, &ps);
        // TODO: 在此处添加使用 hdc 的任何绘图代码...
        EndPaint(hWnd, &ps);
         return 0;
}
LRESULT OnDestroy(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    PostQuitMessage(0);
    return 0;
}

3. 重点是？

LRESULT onLButtonDown(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    //MessageBox(hWnd, _T("是否进入"), _T("欢迎来到该界面"), MB_OK);
    char* str = (char*)"Hello";
    HDC hdc = GetDC(hWnd);
    TextOut(hdc, LOWORD(lParam), HIWORD(lParam), str, strlen(str));
    return 0;
}

本文地址：https://blog.csdn.net/qq_43595030/article/details/107886733