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。