前言

项目中遇到一个多标签的需求，简单介绍下我的实现过程。

3个标签

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需求

具体需求是：

1. 标签的个数不定，可能是0，1，2或3个；
2. 将上述标签排列成一行；
3. 标签的宽度随内容变化，其中文字距离左右是18，距离上下是8。

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实现过程

1. 针对标签内部的需求3，可以自定义HDTabLabel实现上下左右边距。

// HDTabLabel.h
#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface HDTabLabel : UIView

@property (nonatomic, copy) NSString *text;

@end

NS_ASSUME_NONNULL_END


// HDTabLabel.m
#import "HDTabLabel.h"

@interface HDTabLabel ()

@property (nonatomic, strong) UILabel *textLabel;

@end

@implementation HDTabLabel

#pragma mark - initialize
- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        self.layer.cornerRadius = 5;
        self.layer.borderWidth = 1;
        self.layer.borderColor = CGColorFromHex(0xE5E5E5);
        self.layer.backgroundColor = CGColorFromHex(0xFFFFFF);
        
        [self setupConstraintsForSubviews];
    }
    return self;
}

#pragma mark - setter
- (void)setText:(NSString *)text {
    _text = text;
    self.textLabel.text = text;
}

#pragma mark - layout subviews
- (void)setupConstraintsForSubviews {
    [self addSubview:self.textLabel];
    [self.textLabel mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.mas_offset(8);
        make.left.mas_offset(18);
        make.bottom.mas_offset(-8);
        make.right.mas_offset(-18);
    }];
}

#pragma mark - lazy load
- (UILabel *)textLabel {
    if (!_textLabel) {
        _textLabel = [[UILabel alloc]init];
        _textLabel.font = [UIFont italicSystemFontOfSize:15];
    }
    return _textLabel;
}

@end

2. 针对需求1和需求2，是采用UIStackView的自动布局实现的，stackView的宽度由内部的子控件帮忙撑开(内容->Label的固有尺寸->撑开stackView)，所以我们不要设置stackView的宽度约束。

#import "ViewController.h"
#import <Masonry.h>
#import "HDTabLabel.h"

@interface ViewController ()

@property (nonatomic, strong) UIStackView *stackView;

@end

@implementation ViewController

#pragma mark - life cycle
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    self.view.backgroundColor = [UIColor brownColor];
    [self setupConstraintsForSubviews];
    
    // 布局标签
    NSArray *tabs = @[@"不懂拒绝",@"同情心泛滥",@"真诚"];
    for (int i = 0; i < 3; i++) {
        HDTabLabel *tabLabel = [[HDTabLabel alloc]init];
        tabLabel.text = tabs[i];
        [self.stackView addArrangedSubview:tabLabel];
    }
}

#pragma mark - layout subviews
- (void)setupConstraintsForSubviews {
    [self.view addSubview:self.stackView];
    [self.stackView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.centerY.mas_offset(0);
        make.left.mas_offset(20);
    }];
}

#pragma mark - lazy load
- (UIStackView *)stackView {
    if (!_stackView) {
        _stackView = [[UIStackView alloc]init];
        _stackView.spacing = 15;
        _stackView.axis = UILayoutConstraintAxisHorizontal;
        _stackView.alignment = UIStackViewAlignmentFill;
        _stackView.distribution = UIStackViewDistributionFillProportionally;
    }
    return _stackView;
}

@end

标签排列效果

2个标签.png 3个标签.png

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