MyCanvas *canvas = new MyCanvas(subframe, wxPoint(0, 0), wxSize(width, height));
canvas->SetCursor(wxCursor(wxCURSOR_PENCIL));
subframe->canvas = canvas;
MyCanvas *canvas = new MyCanvas(subframe, wxPoint(0, 0), wxSize(width, height));
canvas->SetCursor(wxCursor(wxCURSOR_PENCIL));
subframe->canvas = canvas;