Visual programming - drawing assignment

The operation code is as follows

#include <windows.h>
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInst, LPSTR lpsszCmdLine, int nCmdShow)
{
    
	HWND hwnd;
	MSG Msg;
	WNDCLASS wndclass;
	TCHAR lpszClassName[] = L"My_Drawing";
	TCHAR lpszTitle[] = L" Basic drawing ";
	wndclass.style = 0;
	wndclass.lpfnWndProc = WndProc;
	wndclass.cbClsExtra = 0;
	wndclass.cbWndExtra = 0;
	wndclass.hInstance = hInstance;
	wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
	wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
	wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
	wndclass.lpszMenuName = NULL;
	wndclass.lpszClassName = lpszClassName;
	if (!RegisterClass(&wndclass))
	{
    
		MessageBeep(0);
		return FALSE;
	}
	hwnd = CreateWindow(lpszClassName,
		lpszTitle,
		WS_OVERLAPPEDWINDOW,
		CW_USEDEFAULT,
		CW_USEDEFAULT,
		CW_USEDEFAULT,
		CW_USEDEFAULT,
		NULL,
		NULL,
		hInstance,
		NULL);
	ShowWindow(hwnd, nCmdShow);
	UpdateWindow(hwnd);
	while (GetMessage(&Msg, NULL, 0, 0))
	{
    
		TranslateMessage(&Msg);
		DispatchMessage(&Msg);
	}
	return Msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    
	HDC hdc;
	PAINTSTRUCT ps;
	HPEN hP;											// Define brush handle 
	HBRUSH hB;                                          // Define brush handle 
	switch (message)
	{
    
	case WM_PAINT:
		hdc = BeginPaint(hwnd, &ps);
		SetMapMode(hdc, MM_TEXT);
		Rectangle(hdc, 130, 60, 270, 200);
		hB = CreateHatchBrush(HS_CROSS, RGB(255, 0, 0));

		SelectObject(hdc, hB);
		Ellipse(hdc, 130, 70, 270, 190);
		hP = CreatePen(PS_DASHDOT, 1, RGB(0, 255, 0));

		SelectObject(hdc, hP);
		MoveToEx(hdc, 100, 130, NULL);
		LineTo(hdc, 300, 130);
		MoveToEx(hdc, 200, 30, NULL);
		LineTo(hdc, 200, 230);
		EndPaint(hwnd, &ps);
		DeleteObject(hP);
		DeleteObject(hB);
		break;
	case WM_DESTROY:
		PostQuitMessage(0);
		break;
	default:
		return DefWindowProc(hwnd, message, wParam, lParam);
	}
	return 0;
}

All the code to draw on the window should be added wndproc Functional case WM_PAINT: in
Brush brush first define , Then select hwnd in , Then it can be realized with various drawing functions , Finally, delete the mural brush .
tips： Draw hollow with a brush , Draw solid or filled with grid inside with brush . If both brush and brush are defined , Then it is to draw the outline with a brush , Fill the interior with a brush .