largura = GetSystemMetrics(SM_CXSCREEN);

/**Ouvi a correção, não a rejeiteis e sede sábios. Provérbios 8:33*/

#include <windows.h>
#include "resource.h"

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);

static char font[50] = "Verdana";

char vs[] = "e livrou o justo Ló, enfadado da vida dissoluta dos \
homens abomináveis - 2 Pedro 2:7";

static HFONT tamanhoDaFonte;

static HWND lrg, alt;

int WINAPI WinMain(HINSTANCE hI, HINSTANCE hPI, PSTR szCL, int iCS) {
    static TCHAR szAppName[] = TEXT("Background");
    HWND         hwnd;
    MSG          msg;
    WNDCLASS     wndclass;

    wndclass.style         = CS_HREDRAW | CS_VREDRAW;
    wndclass.lpfnWndProc   = WndProc;
    wndclass.cbClsExtra    = 0;
    wndclass.cbWndExtra    = 0;
    wndclass.hInstance     = hI;
    wndclass.hIcon         = LoadIcon(hI, IDI_ICON);
    wndclass.hCursor       = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = GetSysColorBrush(WHITE_BRUSH);
    wndclass.lpszMenuName  = NULL;
    wndclass.lpszClassName = szAppName;

    if(!RegisterClass(&wndclass)) {
        MessageBox(NULL, TEXT("Error!"), szAppName, MB_ICONERROR);
        return 0;
    }
    hwnd = CreateWindow(
        szAppName,
        TEXT("GetUserName(buffer, &size);"),
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        NULL,
        NULL,
        hI,
        NULL
    );

    ShowWindow(hwnd, iCS);
    UpdateWindow(hwnd);

    while(GetMessage(&msg, NULL, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage (&msg);
        FreeConsole();
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg,WPARAM wP, LPARAM lP) {
    static int  cxClient, cyClient;
    HBRUSH      hBrush;
    HDC         hdc;
    int         i;
    PAINTSTRUCT ps;
    RECT        rect;
    switch(msg) {
        case WM_CREATE:
            CreateWindow(
                TEXT("button"),TEXT("Screen(x, y)"),WS_VISIBLE|WS_CHILD,
                10, 40, 120, 20,
                hwnd, 1, NULL, NULL
            );
            lrg = CreateWindow( /** Largura */
                TEXT("edit"),TEXT(""),WS_VISIBLE|WS_CHILD|DT_CENTER,
                200, 40, 120, 20,
                hwnd, NULL, NULL, NULL
            );
            alt = CreateWindow( /** Altura */
                TEXT("edit"),TEXT(""),WS_VISIBLE|WS_CHILD|DT_CENTER,
                360, 40, 120, 20,
                hwnd, NULL, NULL, NULL
            );
            CreateWindow(
                TEXT("button"),TEXT("2 Pedro 2:7"),WS_VISIBLE|WS_CHILD,
                520, 40, 120, 20,
                hwnd, 2, NULL, NULL
            );
            return 0;
        case WM_SIZE:
            cxClient = LOWORD(lP);
            cyClient = HIWORD(lP);
            return 0;
        case WM_PAINT:
            hdc = BeginPaint(hwnd, &ps);

            char buffer[256];
            DWORD size;
            size = 256;
            GetUserName(buffer, &size);

            for(i = 0; i<65; i++) {
                rect.left   = i * cxClient / 65;
                rect.top    = 0;
                rect.right  = (i + 1) * cxClient / 65;
                rect.bottom = cyClient;
                hBrush = CreateSolidBrush(
                    RGB(
                        min(255, 4 * i),
                        min(210, 4 * i),
                        min(0, 4 * i)
                    )
                );
                FillRect(hdc, &rect, hBrush);
                DeleteObject(hBrush);
            }

            tamanhoDaFonte = CreateFontA(
                25, 0, 0, 0, FW_EXTRABOLD,
                1, 0, 0, 0, 0,
                0, 0, 0, font
            );

            SelectObject(hdc, tamanhoDaFonte);
            SetTextColor(hdc, RGB(20, 20, 0));
            TextOut(hdc, 10, 320, buffer, strlen(buffer));

            EndPaint(hwnd, &ps);
            return 0;
        case WM_COMMAND:
            if(LOWORD(wP)==1) {
                int largura, altura;
                largura = GetSystemMetrics(SM_CXSCREEN);
                altura  = GetSystemMetrics(SM_CYSCREEN);

                static char cnt[400], cnt2[400];

                itoa(largura, cnt, 10);

                itoa(altura, cnt2, 10);

                SetWindowText(lrg, cnt);

                SetWindowText(alt, cnt2);
            }
            if(LOWORD(wP)==2) {
                MessageBox(hwnd, vs, "2 Pedro 2:7", MB_OK);
            }
            return 0;
        case WM_DESTROY:
            PostQuitMessage(0);
            return 0;
    }
    return DefWindowProc(hwnd, msg, wP, lP);
}

/********************Arquivo: resource.h********************/

#define IDI_ICON   1

/********************Arquivo: resource.rc********************/

#include "afxres.h"
#include "resource.h"

IDI_ICON ICON "project1.ico"