第五章 Windows程序设计 笔记

1. Windows 应用程序运行机制

#include <Windows.h>
#include <stdio.h>
LRESULT CALLBACK WinExample1Proc(             //对窗口过程函数进行声明
    HWND hwnd,
    UINT uMsg,
    WPARAM wParam,
    LPARAM lParam
);
int WINAPI WinMain(                          //Win32应用程序入口函数
    HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    LPSTR lpCmdLine,
    int nCmdShow)
{
    WNDCLASS wndcls;                         //创建一个窗口类
    wndcls.cbClsExtra = 0;
    wndcls.cbWndExtra = 0;
    wndcls.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndcls.hCursor = LoadCursor(NULL, IDC_CROSS);
    wndcls.hIcon = LoadIcon(NULL, IDI_ERROR);
    wndcls.hInstance = hInstance;
    wndcls.lpfnWndProc = WinExample1Proc;
    wndcls.lpszClassName =(LPCWSTR)"Example1";
    wndcls.lpszMenuName = NULL;
    wndcls.style = CS_HREDRAW | CS_VREDRAW;
    RegisterClass(&wndcls);                  //注册窗口类

    HWND hwnd;                               //创建窗口，定义一个句柄来唯一标识该窗口
    hwnd = CreateWindow((LPCWSTR)"example1",(LPCWSTR)"一个windows应用程序窗口", WS_OVERLAPPEDWINDOW, 0,0,500,500,NULL,NULL,hInstance,NULL);
    ShowWindow(hwnd, SW_SHOWNORMAL);         //显示和更新窗口
    UpdateWindow(hwnd);
    MSG msg;
    while(GetMessage(&msg, NULL, 0, 0))      //定义消息结构体，并进行消息循环
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}
LRESULT CALLBACK WinExample1Proc(             //编写窗口过程函数，实现消息处理
    HWND hwnd,
    UINT uMsg,
    WPARAM wParam,
    LPARAM lParam
)
{
    char exChar2[] = {"第一个Windows应用程序"};
    switch (uMsg)
    {
    case WM_CHAR:
        char exChar1[40];
        sprintf(exChar1, "键盘输入字符的ASCII值为： %d", wParam);
        MessageBox(hwnd, (LPCWSTR)exChar1, (LPCWSTR)"char", 0);
        break;
    case WM_RBUTTONDOWN:
        MessageBox(hwnd, (LPCWSTR)"右键被按下", (LPCWSTR)"message", 0);
        break;
    case WM_CLOSE:
        if (IDYES == MessageBox(hwnd, (LPCWSTR)"要结束吗？", (LPCWSTR)"提示：", MB_YESNO))
        {
            DestroyWindow(hwnd);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    case WM_PAINT:
        HDC hDC;
        PAINTSTRUCT ps;
        hDC = BeginPaint(hwnd, &ps);
        RECT rt;
        GetClientRect(hwnd, &rt);
        DrawText(hDC, (LPCWSTR)exChar2, strlen(exChar2), &rt, DT_CENTER);
        EndPaint(hwnd, &ps);
        break;
    default:
        return DefWindowProc(hwnd, uMsg, wParam, lParam);
    }
    return 0;
}

从上面的程序结构中，可以发现Win32应用程序有一条很明确的主线： 首先进入WinMain函数，然后设计窗口类，注册窗口类，产生窗口，注册窗口，显示窗口，更新窗口，最后进入消息循环，将消息路由到窗口过程函数中去处理。 这是典型的Windows应用程序的内部运行机制。