描画領域のサイズ

クライアントエリアのサイズを得る

int DrawText(
  HDC hdc ,
  LPTSTR lpchText ,
  int cchText ,
  LPRECT lprc ,
  UINT dwDTFormat ,
);

#include<windows.h>
#include<stdio.h>

LRESULT CALLBACK WndProc(HWND hwnd , UINT msg , WPARAM wp , LPARAM lp) {
	HDC hdc;
	PAINTSTRUCT ps;
	static RECT rect;
	static PCTSTR ctStr = 
		TEXT("Government of the people , by the people , for the people");

	switch (msg) {
	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
	case WM_PAINT:
		hdc = BeginPaint(hwnd , &ps);
		GetClientRect(hwnd , &rect);
		DrawText(hdc , ctStr , -1 , &rect ,
			 DT_CENTER | DT_WORDBREAK );
		EndPaint(hwnd , &ps);
		return 0;
	}
	return DefWindowProc(hwnd , msg , wp , lp);
}

int WINAPI WinMain(HINSTANCE hInstance , HINSTANCE hPrevInstance ,
		 PSTR pCmdLine , int nCmdShow ) {
	HWND hwnd;
	WNDCLASS winc;
	MSG msg;

	winc.style			= CS_HREDRAW |  CS_VREDRAW;
	winc.lpfnWndProc		= WndProc;
	winc.cbClsExtra		= winc.cbWndExtra	= 0;
	winc.hInstance		= hInstance;
	winc.hIcon		= LoadIcon(NULL , IDI_APPLICATION);
	winc.hCursor		= LoadCursor(NULL , IDC_ARROW);
	winc.hbrBackground	= (HBRUSH)GetStockObject(WHITE_BRUSH);
	winc.lpszMenuName	= NULL;
	winc.lpszClassName	= TEXT("KITTY");

	if (!RegisterClass(&winc)) return 0;

	hwnd = CreateWindow(
			TEXT("KITTY") , TEXT("Kitty on your lap") ,
		WS_OVERLAPPEDWINDOW | WS_VISIBLE ,
		CW_USEDEFAULT , CW_USEDEFAULT ,
		CW_USEDEFAULT , CW_USEDEFAULT ,
		NULL , NULL , hInstance , NULL
	);

	if (hwnd == NULL) return 0;

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

GetClientRect()

DrawText()

int DrawText(
  HDC hdc ,
  LPTSTR lpchText ,
  int cchText ,
  LPRECT lprc ,
  UINT uFormat ,
);