Creation of Windows window

The basic code created by the Windows window:

#include <Windows.h>LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);intWINAPI WinMain (__in hinstance hinstance, __in_opt hinstance hprevinstance, __in LPSTR lpCmdLine, __i NintnShowCmd) {TCHAR* AppName = TEXT ("Demo");    HWND hwnd;    MSG msg;    Wndclass Wndclass; Wndclass.style= Cs_hredraw |Cs_vredraw; Wndclass.lpfnwndproc=WndProc; Wndclass.cbclsextra=0; Wndclass.cbwndextra=0; Wndclass.hinstance=hinstance; Wndclass.hicon=LoadIcon (NULL, idi_application); Wndclass.hcursor=loadcursor (NULL, Idc_arrow); Wndclass.hbrbackground=(Hbrush) getstockobject (White_brush); Wndclass.lpszmenuname=NULL; Wndclass.lpszclassname=AppName; if(! RegisterClass (&wndclass)) {MessageBox (NULL, TEXT ("Register Class Error"), AppName,0); return 0; } hwnd=CreateWindow (AppName, TEXT ("Demo"), 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); DispatchMessage (&msg); }    returnMsg.wparam;}    LRESULT CALLBACK WndProc (HWND hwnd, UINT MSG, WPARAM WPARAM, LPARAM LPARAM) {HDC hdc;    Paintstruct PS;    Rect rect; Switch(msg) { Casewm_create: {return 0; }     Casewm_paint: {hdc= BeginPaint (hwnd, &PS); GetClientRect (hwnd,&rect); DrawText (hdc, TEXT ("Ray_xujianguo"), -1, &rect, dt_singleline| dt_center|dt_vcenter); EndPaint (hwnd,&PS); return 0; }     CaseWm_destroy: {postquitmessage (0); return 0; }    }    returnDefWindowProc (hwnd, MSG, WParam, LParam);}

The following section explains:

1. There are some functions we can take a look at their role

    LoadIcon                load icon    loadcursor                load the mouse cursor    getstockobject            Get a drawing object, this example is to get a brush    registerclass            Register a window class    MessageBox                message box    CreateWindow            Create a window    showwindow                display window    UpdateWindow            Redraw Window    GetMessage                getting information from message queues    translatemessage        translating keyboard messages    DispatchMessage            forwarding messages to Windows    BeginPaint                window starts drawing    getclientrect            Gets the size of the window client area    DrawText                displays a text string    endpaint                Drawing of the End window    postquitmessage the            "exit" message into the message queue    DefWindowProc            perform the default message handling

2. Some numeric constants

In the above program we see the Cw_usedefault constants, in fact, we can see from the front of the upper case the type of the constant is what.

    Prefix                        constant    CS                        class style option    CW                        Create window option    DT                        text draw option    IDI                        icon ID number    IDC                        cursor ID number    MB                        message box options    WM                        window message    WS                        window style

3. Understanding Handles

    HINSTANCE                Instance Handle-the program itself    HWND                    window handle    HDC                        device Environment handle

4. Registration of window classes

　　　　

Look at the contents of Wndclass:

　　　　

5. Creation of Windows

The window class simply defines the general characteristics of the window, so you can create many different windows based on the same window class, and you can specify more details when you call the CreateWindow function to create the window.

　　　　

6. Display of Windows

　　　　

7. Message Loops

　　　　

First obtains the message from the message queue, then translates the keyboard the message, then forwards the message to the window procedure function processing, after the window program function processing completes, immediately carries on the next round of message loop.

8. Window procedure Functions

Creation of Windows window