ios - 使用自动布局的 IB_DESIGNABLE 自定义 View 的错位 View 警告和奇怪行为

Question

我创建了一个自定义的 IB 可设计 View (参见下面的代码)，它在 IB 中正确呈现并且在运行时也能正常工作。但是，在收到有关 View 放错位置的警告时，我无法在 Interface Builder 中手动调整 View 大小(触摸调整大小 handle 时， View 将在其容器中跳来跳去)。

对于各种不同的布局，我会得到相同或相似的行为。您是否知道我在这里做错了什么，或者这只是 IB 中的一个错误？

(PS:我不能忽略警告)

编辑:添加约束截图:

这是代码(标题):

    IB_DESIGNABLE
    @interface AKATestView : UIView
    @end

实现:

    @interface AKATestView()

    @property(nonatomic)BOOL subviewsCreated;
    @property(nonatomic)BOOL subviewConstraintsCreated;
    @property(nonatomic)NSDictionary* views;

    @end

    @implementation AKATestView

    - (id)initWithCoder:(NSCoder *)aDecoder
    {
        self = [super initWithCoder:aDecoder];
        if (self) {
            [self setupAfterInit];
        }
        return self;
    }
    - (instancetype)initWithFrame:(CGRect)frame
    {
        self = [super initWithFrame:frame];
        if (self) {
            [self setupAfterInit];
        }
        return self;
    }

    - (void)setupAfterInit
    {
        [self createSubviews];
    }

    - (void)createSubviews
    {
        if (!self.subviewsCreated)
        {
            self.translatesAutoresizingMaskIntoConstraints = NO;

            UILabel* labelView = [[UILabel alloc] initWithFrame:CGRectZero];
            labelView.text = @"Name";
            labelView.translatesAutoresizingMaskIntoConstraints = NO;
            [self addSubview:labelView];

            UITextField* textField = [[UITextField alloc] initWithFrame:CGRectZero];
            textField.borderStyle = UITextBorderStyleRoundedRect;
            textField.placeholder = @"Enter some text";
            textField.translatesAutoresizingMaskIntoConstraints = NO;
            [self addSubview:textField];

            UILabel* errorMessageLabel = [[UILabel alloc] initWithFrame:CGRectZero];
            errorMessageLabel.text = @"Error message";
            errorMessageLabel.translatesAutoresizingMaskIntoConstraints = NO;
            [self addSubview:errorMessageLabel];

            self.views = @{ @"label": labelView, @"editor": textField, @"errorMessageLabel": errorMessageLabel };
            self.subviewsCreated = YES;

            [self setNeedsUpdateConstraints];
        }
    }

    - (void)updateConstraints
    {
        if (!self.subviewConstraintsCreated)
        {
            NSDictionary* metrics =
            @{ @"pt": @(4), @"pr": @(4), @"pb": @(4), @"pl": @(4),
               @"labelWidth": @(100),
               @"errorPl": @(4 + 100 + 4),
               @"hsLabelEditor": @(4), @"vsEditorError": @(2)
               };
            NSArray* specs =
            @[ @{ @"format": @"H:|-(pl)-[label(labelWidth)]-(hsLabelEditor)-[editor]-(pr)-|",
                  @"options": @(NSLayoutFormatAlignAllFirstBaseline) },
               @{ @"format": @"V:|-(pt)-[editor]-(vsEditorError)-[errorMessageLabel]-(pb)-|",
                  @"options": @(NSLayoutFormatAlignAllLeading|NSLayoutFormatAlignAllTrailing) }
               ];
            for (NSDictionary* spec in specs)
            {
                NSString* format = spec[@"format"];
                NSUInteger options = ((NSNumber*)spec[@"options"]).unsignedIntegerValue;
                NSArray* constraints = [NSLayoutConstraint constraintsWithVisualFormat:format
                                                                               options:options
                                                                               metrics:metrics
                                                                                 views:self.views];
                [self addConstraints:constraints];
            }

            self.subviewConstraintsCreated = YES;
        }
        [super updateConstraints];
    }

    @end

Answer 1

尝试在 createSubviews 方法中删除 self.translatesAutoresizingMaskIntoConstraints = NO;。 IB 似乎是依靠这个翻译来对设计师进行正确的测量。我有完全相同的问题，这解决了它。

对于 subview ，我仍然有 translatesAutosizingMaskIntoConstraints 到 NO。我确认即使将此设置为 YES 也不会生成任何额外的约束。希望您也是如此!