ios - 如何处理 iOS 11 Navigation BarButtonItems 错误？

Question

我在 iOS 11 中发现了一个 UINavigationBar 错误。首先在 viewDidLoad 中使用 self.navigationItem.rightBarButtonItems = @[fixSpaceItem, item] 设置导航项按钮。并使用手势弹回，但我并没有真正弹回，当弹回开始时，我松开手指让 viewcontroller 取消弹回，然后右导航按钮项目消失。左边的项目按钮有同样的问题。要重现此错误，您必须添加 fixSpaceItem，例如 [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil]。真实设备而非模拟器可以重现该错误。 这是我的主要代码:

- (void)viewDidLoad {
    [super viewDidLoad];

    self.navigationController.interactivePopGestureRecognizer.enabled = YES;
    self.navigationController.interactivePopGestureRecognizer.delegate = self;

    self.navigationItem.rightBarButtonItems = @[[self negativeSpacerWithWidth:5],[self rightButton]];
    self.navigationItem.leftBarButtonItems = @[[self negativeSpacerWithWidth:5], [self leftButton]];

}

- (UIBarButtonItem *)leftButton {
    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 35, 35)];
    [button setImage:[UIImage imageNamed:@"icon_app_back_normal"] forState:UIControlStateNormal];
    [button addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
    UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithCustomView:button];
    return item;
}

- (UIBarButtonItem *)rightButton {
    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 35, 35)];
    [button setImage:[UIImage imageNamed:@"setting"] forState:UIControlStateNormal];
    UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithCustomView:button];
    return item;
}

- (UIBarButtonItem *)negativeSpacerWithWidth:(CGFloat)width {
    UIBarButtonItem *spacer = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
    [spacer setWidth:width];
    return spacer;
}

Answer 1

当您将 FixedSpace BarButtonItem 添加到 BarButtonItem 数组 时，这似乎是一个错误。如果要为导航项设置偏移量，可能需要使用其他方式，例如更改按钮的 imageEdgeInsets。

- (void)viewDidLoad {
    [super viewDidLoad];

    // Do not set Fixed Space type button item.
    self.navigationItem.leftBarButtonItem = [self leftButton];
    self.navigationItem.rightBarButtonItem = [self rightButton];

    // It work too
    //self.navigationItem.leftBarButtonItems = @[[self leftButton], [self leftButton]];
    //self.navigationItem.rightBarButtonItems = @[[self rightButton], [self rightButton]];


    self.navigationController.interactivePopGestureRecognizer.enabled = YES;
    self.navigationController.interactivePopGestureRecognizer.delegate = self;
}

- (UIBarButtonItem *)leftButton
{
    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 35, 35)];
    //...

    // to add offset you want
    button.imageEdgeInsets = UIEdgeInsetsMake(0, -15, 0, 15);

    UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithCustomView:button];
    return item;
}

- (UIBarButtonItem *)rightButton
{
    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 35, 35)];
    //...

    // to add offset you want
    button.imageEdgeInsets = UIEdgeInsetsMake(0, 15, 0, -15);

    UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithCustomView:button];
    return item;
}