iOS13后，presentViewController不能铺满全屏（oc版）

BaseNavViewController *navVc = [[BaseNavViewController alloc] initWithRootViewController:loginVc];
    
    //加上下面这句=0的代码，登录页就顶到最上面去了
    navVc.modalPresentationStyle = 0;
    
    [self presentViewController:navVc animated:YES completion:nil];