XLSideViewController is a sidebar 一个侧边栏的抽屉 #####只需传入两个控制器即可，支持手势拖拽，同时也支持点击隐藏或显示侧边栏抽屉，实时监听侧边栏抽屉的显示隐藏状态
XLSideViewController *sideViewController = [[XLSideViewController alloc] initWithMainViewController:navigationController leftViewController:leftViewController];
self.window.rootViewController = sideViewController;
