iOS 11 导航栏按钮偏移问题

  iOS 11之前  ,导航栏偏移量是正常显示的 ,不需要修改什么, 如下: 

UIButton *leftButton = [UIButton buttonWithType:UIButtonTypeCustom];

    leftButton.frame = CGRectMake(0, 0, 27, 27);

    [leftButton setImage:[UIImage imageNamed:@"back1.png"] forState:UIControlStateNormal];

    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithCustomView:leftButton];

    [leftButton addTarget:self action:@selector(backButton) forControlEvents:UIControlEventTouchUpInside];

但iOS 11 之后显示偏移严重 ,简单粗暴的方法就是 改变按钮的 contentEdgeInsets和imageEdgeInsets的值成功改变了按钮的偏移问题 

UIButton *leftBtn = [[UIButton alloc] initWithFrame:CGRectMake(0,0, 44,44)];

    leftBtn.contentEdgeInsets =UIEdgeInsetsMake(0, -30,0, 0);

    leftBtn.imageEdgeInsets =UIEdgeInsetsMake(0, -25,0, 0);

    [leftBtn setImage:[UIImage imageNamed:@"back1.png"]forState:UIControlStateNormal];

    [leftBtn addTarget:self action:@selector(backButton)forControlEvents:UIControlEventTouchUpInside];

    UIBarButtonItem *leftItem = [[UIBarButtonItem alloc] initWithCustomView:leftBtn];

    self.navigationItem.leftBarButtonItems =@[leftItem];