Разложить все "по полочкам"

#include <windows.h>
#include <windowsx.h>
#include<stdlib.h>
#include <wchar.h>
 
class WINDOWMAIN
{
public:
    HWND hwnd;
    void Create_Window(LPCWSTR Name_Prog);
    void Create_Button(LPCWSTR text,int x,int y,int x2,int y2);
    void Show_Window();
    bool Reg_Window(HINSTANCE hInstance,LPCWSTR lpzClassName,WNDPROC lpfnWndProc);
    HDC Get_DC(HWND hwnd);
private:
    WNDCLASS we;
};

#include "CWindow.h"
bool WINDOWMAIN::Reg_Window(HINSTANCE hInstance, LPCWSTR lpzClassName,WNDPROC lpfnWndProc)
   {
       ZeroMemory(&we,sizeof(we));
       we.lpfnWndProc=lpfnWndProc;
       we.hInstance=hInstance;
       we.hIcon=LoadIcon(NULL,IDI_APPLICATION);
       we.hCursor=LoadCursor(NULL,IDC_ARROW);
       we.hbrBackground=GetStockBrush(WHITE_BRUSH);
       we.lpszClassName= lpzClassName;
      if (RegisterClass(&we)!=0) 
            return true;
              else 
            return false;
   }
 
  void WINDOWMAIN::Create_Window(LPCWSTR Name_Prog)
  {
    hwnd=CreateWindow(L"MyWindowClass",Name_Prog,
WS_OVERLAPPEDWINDOW,500,200,230,250,
HWND_DESKTOP,NULL,NULL,NULL);  
  }
 
  void WINDOWMAIN::Show_Window()
  {
ShowWindow(hwnd,SW_SHOW);       
  }
 
 HDC WINDOWMAIN::Get_DC(HWND hwnd)
  {
     if (GetDC(hwnd)!=NULL)
      return GetDC(hwnd);
     else
         return NULL;
  }

#include "CWindows.cpp"
LRESULT CALLBACK  WndProc(HWND hWnd,UINT uMsg, WPARAM wParam, LPARAM lParam);
 
WINDOWMAIN MyObject;
  int WINAPI  WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR, int )
 
   {
       MSG Msg; 
      
       if (MyObject.Reg_Window(hInstance,L"MyWindowClass",WndProc)) 
      {
          MyObject.Create_Window(L"Project");
          MyObject.Show_Window();
          dc=MyObject.Get_DC(MyObject.hwnd);
          
 
         while(GetMessage(&Msg,NULL,0,0))
           {    
             DispatchMessage(&Msg);
             TranslateMessage(&Msg);
           }
      }
return 0;
}
 
LRESULT CALLBACK  WndProc(HWND hWnd,UINT uMsg, WPARAM wParam, LPARAM lParam)
{   
    switch(uMsg)
{
 
    case WM_DESTROY:
PostQuitMessage(0);
    break;
 
default:
return(DefWindowProc(hWnd,uMsg,wParam,lParam)) ; 
}
}

#include "CWindows.cpp"
 
LRESULT CALLBACK  WndProc(HWND hWnd,UINT uMsg, WPARAM wParam, LPARAM lParam);
 
HDC dc;
WINDOWMAIN MyObject; 
 
  int WINAPI  WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR, int )
 
   {
       MSG Msg;   
      
      
 
       if (MyObject.Reg_Window(hInstance,L"MyWindowClass",WndProc)) 
      {
          MyObject.Create_Window(L"Project");
          MyObject.Show_Window();
          dc=MyObject.Get_DC(MyObject.hwnd);
          
 
         while(GetMessage(&Msg,NULL,0,0))
           {    
             DispatchMessage(&Msg);
             TranslateMessage(&Msg);
           }
      }
return 0;
}
 
LRESULT CALLBACK  WndProc(HWND hWnd,UINT uMsg, WPARAM wParam, LPARAM lParam)
{
 
    switch(uMsg)
{
 
    case WM_DESTROY:
PostQuitMessage(0);
    break;
 
default:
return(DefWindowProc(hWnd,uMsg,wParam,lParam)) ; 
}
}