学习windows编程 day1

#include <windows.h>
#include <strsafe.h>
/*
        任务：去掉标题栏和边框
*/

//#define LineHeight 15 这是自己猜测的行高，不要这样做

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
    static TCHAR szClassName[] = TEXT("MyWindows2");
    HWND hwnd;
    MSG msg;


    //注册一个窗口类
    //注册窗口类
    WNDCLASS wndclass;

    wndclass.hInstance = hInstance;
    wndclass.lpszClassName = szClassName;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.lpfnWndProc = WndProc;
    wndclass.lpszMenuName = NULL;
    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.style = CS_HREDRAW;

    if (!RegisterClass(&wndclass))
    {
        MessageBox(NULL, L"Error", L"Error", MB_ICONERROR);
        return 0;
    }

    //创建窗口
    hwnd = CreateWindow(
        szClassName,
        TEXT("MyFirstPractice"),
        //方法一
        //WS_OVERLAPPEDWINDOW &~WS_CAPTION &~WS_SYSMENU &~WS_SIZEBOX,
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        NULL,
        NULL,
        hInstance,
        NULL
        );

    ShowWindow(hwnd, nShowCmd);
    UpdateWindow(hwnd);

    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);

        //此处分发消息，调用消息回调函数，
        //同时消息回调函数的返回值作为DIspatchMessage的返回值返回，
        //一般讲这个返回值忽略
        DispatchMessage(&msg);
        /*
        The return value specifies the value returned by the window procedure. Although its meaning depends on the message being dispatched, the return value generally is ignored. 
        返回值指定窗口过程返回的值。尽管它的含义依赖于发送的消息，但是返回值通常被忽略。
        */
    }

    return msg.wParam;
}

/*
WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
和
typedef struct tagMSG {
HWND   hwnd;
UINT   message;
WPARAM wParam;
LPARAM lParam;
DWORD  time;
POINT  pt;
} MSG, *PMSG;
前四个参数一致

操作系统直接使用msg前四位作为参数传入窗口回调函数
*/

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    RECT rect;

    TCHAR szBuffer[128];
    size_t iTarget;
    TEXTMETRIC tm;
    static int cxChar, cyChar;

    switch (message)
    {
    case WM_CREATE:
        //在创建时就设置为静态全局变量，在后面的消息触发是就可以直接使用了
        hdc = GetDC(hwnd);

        //获得当前字体的尺寸
        GetTextMetrics(hdc,&tm);
        //系统获取行距等信息，不要自己猜测
        cxChar = tm.tmAveCharWidth;
        cyChar = tm.tmHeight + tm.tmExternalLeading;

        ReleaseDC(hwnd,hdc);
    case WM_SIZE:
        ; LONG_PTR s = GetWindowLongPtr(hwnd, GWL_STYLE);
        //s = s &~WS_CAPTION &~WS_SYSMENU&~WS_SIZEBOX;
        s = s&~WS_SIZEBOX;
        SetWindowLongPtr(hwnd,GWL_STYLE, s);
        break;
    case WM_LBUTTONDOWN:
        if (IDYES == MessageBox(NULL, L"Are you sure to quit?", L"Info", MB_YESNO)){
            PostQuitMessage(0);
        }
        break;
    case WM_NCLBUTTONUP:
        MessageBox(NULL, L"Clicked on Not client Area", L"Info", NULL);
        break;
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        GetClientRect(hwnd, &rect);
        //SetTextAlign(hdc, GetTextAlign(hdc) | TA_CENTER);
        int i = 0;
        for (; i < 10;i++)
        {
            //使用安全的字符串方法，防止溢出等原因
            StringCchPrintf(szBuffer, 128, TEXT("%d: %s"),i+1,TEXT("I love C++"));
            //wsprintf(szBuffer, TEXT("%d: %s"),i+1, TEXT("I love C++"));
            
            StringCchLength(szBuffer, 128, &iTarget);
            //取代了lstrlen
            //TextOut(hdc, 0,i*LineHeight, szBuffer, lstrlen(szBuffer));
            TextOut(hdc, cxChar, i*cyChar, szBuffer, iTarget);

        }
        //TextOut(hdc, 400, 300, L"this is my second program", 20);
        //DrawText(hdc, L"this is my second program", -1, &rect, DT_CENTER | DT_VCENTER | DT_SINGLELINE);
        EndPaint(hwnd, &ps);
        break;
    case WM_CLOSE:
        if (IDYES == MessageBox(NULL, L"Are you sure to quit?", L"Info", MB_YESNO))
        {
            DestroyWindow(hwnd);
        }
        break;
    case WM_DESTROY:
        MessageBox(NULL, L"GUI is close,deal sql before quit", L"Info", MB_OK);
        PostQuitMessage(0);
        break;
    case WM_QUIT:
        break;
    default:
        return DefWindowProc(hwnd, message, wParam, lParam);
    }
    return 0;
}