API - 키보드 입력

#include <windows.h>

LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
HINSTANCE g_hInst;
LPCTSTR lpszClass=TEXT("Key");

int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpszCmdParam,int nCmdShow)
{
 HWND hWnd;
 MSG Message;
 WNDCLASS WndClass;
 g_hInst=hInstance;
 
 WndClass.cbClsExtra=0;
 WndClass.cbWndExtra=0;
 WndClass.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);
 WndClass.hCursor=LoadCursor(NULL,IDC_CROSS);
 WndClass.hIcon=LoadIcon(NULL,IDI_ERROR);
 WndClass.hInstance=hInstance;
 WndClass.lpfnWndProc=WndProc;
 WndClass.lpszClassName=lpszClass;
 WndClass.lpszMenuName=NULL;
 WndClass.style=CS_HREDRAW | CS_VREDRAW;
 RegisterClass(&WndClass);

 hWnd=CreateWindow(lpszClass,lpszClass, WS_OVERLAPPEDWINDOW|WS_VSCROLL|WS_HSCROLL,
  CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,
  NULL,(HMENU)NULL,hInstance,NULL);
 ShowWindow(hWnd,nCmdShow);
 
 while (GetMessage(&Message,NULL,0,0)) {
  TranslateMessage(&Message);
  DispatchMessage(&Message);
 }
 return (int)Message.wParam;
}

LRESULT CALLBACK WndProc(HWND hWnd,UINT iMessage,WPARAM wParam,LPARAM lParam)
{
 HDC hdc;
 PAINTSTRUCT ps;
 static TCHAR str[256];
 int len;

 switch (iMessage) {
 case WM_DESTROY:
  PostQuitMessage(0);
  return 0;
 case WM_CHAR:
  len=lstrlen(str);
  str[len]=(TCHAR)wParam;
  str[len+1]=0;
  InvalidateRect(hWnd,NULL,FALSE);
  return 0;
 case WM_PAINT:
  hdc=BeginPaint(hWnd, &ps);
  TextOut(hdc, 100, 100, str, lstrlen(str));
  EndPaint(hWnd, &ps);
  return 0;

 }
 return(DefWindowProc(hWnd,iMessage,wParam,lParam));
}

 

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①static TCHAR str[256];

============================================

②case WM_CHAR:
  len=lstrlen(str);
  str[len]=(TCHAR)wParam;
  str[len+1]=0;
③InvalidateRect(hWnd,NULL,FALSE);
  return 0;
④case WM_PAINT:
  hdc=BeginPaint(hWnd, &ps);
  TextOut(hdc, 100, 100, str, lstrlen(str));
  EndPaint(hWnd, &ps);
============================================

key-akon47.exe