화면 DC에 있는 색상들을 메모리 DC로 옮길 수 있나요?

#include <windows.h>
 
LRESULT CALLBACK WinProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam);
int APIENTRY WinMain(HINSTANCE hinstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd);
 
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd) {
	WNDCLASS WndCls;
	WndCls.cbClsExtra=0;
	WndCls.cbWndExtra=0;
	WndCls.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);
	WndCls.hCursor=LoadCursor(NULL, IDC_ARROW);
	WndCls.hIcon=NULL;
	WndCls.hInstance=hInstance;
	WndCls.lpfnWndProc=WinProc;
	WndCls.lpszClassName=TEXT("copy");
	WndCls.lpszMenuName=NULL;
	WndCls.style=CS_HREDRAW | CS_VREDRAW;
	RegisterClass(&WndCls);
	HWND hwnd=CreateWindow(TEXT("copy"), TEXT("win"), WS_OVERLAPPEDWINDOW, 300, 300, 500, 500, NULL, NULL, hInstance, NULL);
	ShowWindow(hwnd, nShowCmd);
	MSG message;
	while(  GetMessage(&message, NULL, 0, 0)  ) {
		TranslateMessage(&message);
		DispatchMessage(&message);
	}
	return message.wParam;
}
 
LRESULT CALLBACK WinProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
	switch(message) {
		case WM_DESTROY:
			PostQuitMessage(0);
			return 0;
		case WM_KEYDOWN:
			switch(wparam) {
				case VK_LEFT:
					HDC hdc=GetDC(hwnd);
					HDC memDC=CreateCompatibleDC(hdc);
 
 
					StretchBlt(memDC, 0, 0, 200, 200, hdc, 0, 0, 200, 200, SRCCOPY);
					StretchBlt(hdc, 200, 200, 200, 200, memDC, 0, 0, 200, 200, SRCCOPY);					
//위 두 줄의 코드에서 복사가 제대로 안됩니다.
 
					DeleteDC(memDC);
					ReleaseDC(hwnd, hdc);
					break;
			}
			return 0;
		case WM_PAINT:
			PAINTSTRUCT pst;
			HDC hdc=BeginPaint(hwnd, &pst);
			HBRUSH new_brush=CreateSolidBrush(0x000000);
			HBRUSH backup_brush=(HBRUSH)SelectObject(hdc, new_brush);
 
			Rectangle(hdc, 0, 0, 200, 200);
			SelectObject(hdc, backup_brush);
			DeleteObject(new_brush);
			EndPaint(hwnd, &pst);
 
			return 0;
	}
	return DefWindowProc(hwnd, message, wparam, lparam);
}