第五章 Windows程式設計 筆記

1. Windows 應用程式運行機制

#include <Windows.h>#include <stdio.h>LRESULT CALLBACK WinExample1Proc(             //對視窗過程函數進行聲明    HWND hwnd,    UINT uMsg,    WPARAM wParam,    LPARAM lParam);int WINAPI WinMain(                          //Win32應用程式入口函數    HINSTANCE hInstance,    HINSTANCE hPrevInstance,    LPSTR lpCmdLine,    int nCmdShow){    WNDCLASS wndcls;                         //建立一個視窗類別    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);                  //註冊視窗類別    HWND hwnd;                               //建立視窗，定義一個控制代碼來唯一標識該視窗    hwnd = CreateWindow((LPCWSTR)"example1",(LPCWSTR)"一個windows應用程式視窗", WS_OVERLAPPEDWINDOW, 0,0,500,500,NULL,NULL,hInstance,NULL);    ShowWindow(hwnd, SW_SHOWNORMAL);         //顯示和更新視窗    UpdateWindow(hwnd);    MSG msg;    while(GetMessage(&msg, NULL, 0, 0))      //定義訊息結構體，並進行訊息迴圈    {        TranslateMessage(&msg);        DispatchMessage(&msg);    }    return msg.wParam;}LRESULT CALLBACK WinExample1Proc(             //編寫視窗過程函數，實現訊息處理    HWND hwnd,    UINT uMsg,    WPARAM wParam,    LPARAM lParam){    char exChar2[] = {"第一個Windows應用程式"};    switch (uMsg)    {    case WM_CHAR:        char exChar1[40];        sprintf(exChar1, "鍵盤輸入字元的ASCII值為： %d", wParam);        MessageBox(hwnd, (LPCWSTR)exChar1, (LPCWSTR)"char", 0);        break;    case WM_RBUTTONDOWN:        MessageBox(hwnd, (LPCWSTR)"右鍵被按下", (LPCWSTR)"message", 0);        break;    case WM_CLOSE:        if (IDYES == MessageBox(hwnd, (LPCWSTR)"要結束嗎？", (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;}

從上面的程式結構中，可以發現Win32應用程式有一條很明確的主線： 首先進入WinMain函數，然後設計視窗類別，註冊視窗類別，產生視窗，註冊視窗，顯示視窗，更新視窗，最後進入訊息迴圈，將訊息路由到視窗過程函數中去處理。 這是典型的Windows應用程式的內部運行機制。