Win32 SDK基础(四)之如何从零开始创建windows窗口的第二步-木庄网络博客

本文摘自PHP中文网，作者黄舟，侵删。

3.5 显示窗口。

创建了窗口之后，如果要想运行时能够看见窗口，我们还需要显式的设置显示窗口：

1 2	`ShowWindow(hWnd, SW_SHOW);` `UpdateWindow(hWnd);`

ShowWindow和UpdateWindow都是系统的API，前者是设置窗口的显示属性。后者重新更新窗口属性，只有更新之后，属性才会生效。经过了上述步骤，我们的WinMain函数已经变成了如下：

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR    lpCmdLine,
_In_ int       nCmdShow)
{
    //注册窗口类
    WNDCLASSEX wce = { 0 };
    wce.cbSize = sizeof(wce);
    wce.cbClsExtra = 0;
    wce.cbWndExtra = 0;
    wce.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wce.hCursor = NULL;
    wce.hIcon = NULL;
    wce.hIconSm = NULL;
    wce.hInstance = hInstance;
    wce.lpfnWndProc = wndProc;
    wce.lpszClassName = “Main”;
    wce.lpszMenuName = NULL;
    wce.style = CS_HREDRAW | CS_VREDRAW;
    ATOM nAtom = RegisterClassEx(&wce);
    if (!nAtom )
    {
        MessageBox(NULL, "注册失败", "Infor", MB_OK);
        return 0;
    }
     
    //创建窗口 
    HWND hWnd = CreateWindowEx(0, “Main”, “Window”, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, g_hInstance, NULL);
    //显示窗口 
   ShowWindow(hWnd, SW_SHOW); 
   UpdateWindow(hWnd); 
}

3.6 开启消息循环

所谓的消息循环，其实就是一个死循环，不断的通过GetMessage捕捉着窗口的消息，再通过TranslateMessage将虚拟键消息转换为字符消息,然后通过DispatchMessage将消息分派给我们的窗口程序进行处理（所谓处理就是调用我们定义的窗口处理函数WinProc）：

void Message()
{
    MSG nMsg = { 0 };
    while (GetMessage(&nMsg, NULL, 0, 0))
    {
        TranslateMessage(&nMsg);
        DispatchMessage(&nMsg);
    }
}

完成了消息循环之后，我们最终的代码如下（这里面对窗口注册的程序进行了封装，但是过程是一致的）：

#include<windows.h>
HINSTANCE g_hInstance = 0;
//窗口处理函数
LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);//可以使GetMessage返回0
        break;
    default:
        break;
    }
    return DefWindowProc(hWnd, uMsg, wParam, lParam);
}
//注册窗口类
BOOL Register(LPSTR lpClassName, WNDPROC wndProc)
{
    WNDCLASSEX wce = { 0 };
    wce.cbSize = sizeof(wce);
    wce.cbClsExtra = 0;
    wce.cbWndExtra = 0;
    wce.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wce.hCursor = NULL;
    wce.hIcon = NULL;
    wce.hIconSm = NULL;
    wce.hInstance = g_hInstance;
    wce.lpfnWndProc = wndProc;
    wce.lpszClassName = lpClassName;
    wce.lpszMenuName = NULL;
    wce.style = CS_HREDRAW | CS_VREDRAW;
    ATOM nAtom = RegisterClassEx(&wce);
    if (nAtom == 0)
        return FALSE;
    return true;
 
}
//创建主窗口
HWND CreateMain(LPSTR lpClassName, LPSTR lpWndName)
{
    HWND hWnd = CreateWindowEx(0, lpClassName, lpWndName,
        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, g_hInstance, NULL);
    return hWnd;
}
//显示窗口
void Display(HWND hWnd)
{
    ShowWindow(hWnd, SW_SHOW);
    UpdateWindow(hWnd);
}
//消息循环
void Message()
{
    MSG nMsg = { 0 };
    while (GetMessage(&nMsg, NULL, 0, 0))
    {
        TranslateMessage(&nMsg);
        DispatchMessage(&nMsg);
    }
}
int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
    _In_opt_ HINSTANCE hPrevInstance,
    _In_ LPWSTR    lpCmdLine,
    _In_ int       nCmdShow)
{
    // TODO: Place code here.
 
    g_hInstance = hInstance;
    BOOL nRet = Register("Main", WndProc);
    if (!nRet)
    {
        MessageBox(NULL, "注册失败", "Infor", MB_OK);
        return 0;
    }
    HWND hWnd = CreateMain("Main", "window");
    Display(hWnd);
    Message();
    return 0;
}