iOS Tabbar中间添加凸起可旋转按钮(定制按钮)

前言

最近的项目中有需求在tabbar中间添加凸起按钮,并且点击时按钮要旋转,看了仿闲鱼的凸起,点击后是present出来View,而不是像常规的tabbar上添加一个页面(亲测,闲鱼的超出Tabbar部分点击是没有反应的,这是bug啊,下文对这个问题有详解),所以不符合要求,经过一段摸索最后得的一个比较好的效果,下面看效果图

效果图.gif

(本文简书地址:https://www.jianshu.com/p/5160a1b48679

使用方法

1、支持Cocoapods
OC版本 pod 'MCTabBarController'
Swift版本 pod 'MCTabBarControllerSwift'
2、将demo下载,MCTabBarController文件的内容拖入到项目中,直接创建自己的XXTabBarController 继承自MCTabBarController即可,具体的可参考demo中的例子 MCTabBarController ,如果对你要帮助,不要吝啬你的star哦🌟。

需求分析 (本文以Bulge效果为例)

  • tabbar有5个item,每个对应一个页面
  • 中间item为凸起按钮
  • 中间按钮点击后旋转

实现思路

创建MCTabBar 继承自UITabBar,重写了中间按钮,并开放了中间按钮的各种属性

typedef NS_ENUM(NSUInteger, MCTabBarCenterButtonPosition){
    MCTabBarCenterButtonPositionCenter, // 居中
    MCTabBarCenterButtonPositionBulge // 凸出一半
};

@interface MCTabBar : UITabBar
/**
 中间按钮
 */
@property (nonatomic, strong) UIButton *centerBtn;

/**
  中间按钮图片
 */
@property (nonatomic, strong) UIImage *centerImage;
/**
 中间按钮选中图片
 */
@property (nonatomic, strong) UIImage *centerSelectedImage;

/**
 中间按钮偏移量,两种可选,也可以使用centerOffsetY 自定义
 */
@property (nonatomic, assign) MCTabBarCenterButtonPosition position;

/**
  中间按钮偏移量,默认是居中
 */
@property (nonatomic, assign) CGFloat centerOffsetY; 

/**
  中间按钮的宽和高,默认使用图片宽高
*/
@property (nonatomic, assign) CGFloat centerWidth, centerHeight;
  • 添加凸起按钮
    我们可以在MCTabBar上添加我们的凸起按钮,让他的位置在没有设置的中间按钮偏上,按钮的点击和中间按钮点击绑定,但是会有下面的问题
    1、因为凸起按钮的frame超出了MCTabBar的frame,这样超出的区域点击按钮会没有响应(图二红框区域),原因和解决办法详情参考我的这篇iOS UIButton 点击无响应的解决办法,所以要处理点击无效的问题
图二

2、由于UITabBar是readonly的,所以我们不能直接对他进行赋值,这里利用KVC访问私有变量将MCTabBar赋值给"tabBar"
具体实现
MCTabBar

#import "MCTabBar.h"
#import "UIView+MCExtension.h"

#define MCTabBarItemHeight    49.0f

@interface MCTabBar()
@end
@implementation MCTabBar
- (instancetype)init{
    if (self = [super init]){
        [self initView];
    }
    return self;
}

- (void)initView{
    _centerBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    //去除选择时高亮
    _centerBtn.adjustsImageWhenHighlighted = NO;
    [self addSubview:_centerBtn];
}

// 设置layout
- (void)layoutSubviews {
    [super layoutSubviews];
    switch (self.position) {
        case MCTabBarCenterButtonPositionCenter:
            _centerBtn.frame = CGRectMake(([UIScreen mainScreen].bounds.size.width - _centerWidth)/2.0, (MCTabBarItemHeight - _centerHeight)/2.0 + self.centerOffsetY, _centerWidth, _centerHeight);
            break;
        case MCTabBarCenterButtonPositionBulge:
             _centerBtn.frame = CGRectMake(([UIScreen mainScreen].bounds.size.width - _centerWidth)/2.0, -_centerHeight/2.0 + self.centerOffsetY, _centerWidth, _centerHeight);
            break;
        default:
            break;
    }
    
    _centerBtn.originX = ([UIScreen mainScreen].bounds.size.width - _centerBtn.width)/2.0;
}

- (void)setCenterImage:(UIImage *)centerImage {
    _centerImage = centerImage;
    // 如果设置了宽高则使用设置的大小
    if (self.centerWidth <= 0 && self.centerHeight <= 0){
        //根据图片调整button的位置(默认居中,如果图片中心在tabbar的中间最上部,这个时候由于按钮是有一部分超出tabbar的,所以点击无效,要进行处理)
        _centerWidth = centerImage.size.width;
        _centerHeight = centerImage.size.height;
    }
    [_centerBtn setImage:centerImage forState:UIControlStateNormal];
}

- (void)setCenterSelectedImage:(UIImage *)centerSelectedImage {
    _centerSelectedImage = centerSelectedImage;
    [_centerBtn setImage:centerSelectedImage forState:UIControlStateSelected];
}

//处理超出区域点击无效的问题
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{
    if (self.hidden){
        return [super hitTest:point withEvent:event];
    }else {
        //转换坐标
        CGPoint tempPoint = [self.centerBtn convertPoint:point fromView:self];
        //判断点击的点是否在按钮区域内
        if (CGRectContainsPoint(self.centerBtn.bounds, tempPoint)){
            //返回按钮
            return _centerBtn;
        }else {
            return [super hitTest:point withEvent:event];
        }
    }
}

利用KVC赋值

//MCTabBarController.m
- (void)viewDidLoad {
    [super viewDidLoad];
    _mcTabbar = [[MCTabBar alloc] init];
    [_mcTabbar.centerBtn addTarget:self action:@selector(buttonAction:) forControlEvents:UIControlEventTouchUpInside];
    //利用KVC 将自己的tabbar赋给系统tabBar
    [self setValue:_mcTabbar forKeyPath:@"tabBar"];
    self.delegate = self;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}

- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{
    
    _mcTabbar.centerBtn.selected = (tabBarController.selectedIndex == self.viewControllers.count/2);
    
    if (self.mcDelegate){
        [self.mcDelegate mcTabBarController:tabBarController didSelectViewController:viewController];
    }
}

- (void)buttonAction:(UIButton *)button{
    NSInteger count = self.viewControllers.count;
    self.selectedIndex = count/2;//关联中间按钮
    [self tabBarController:self didSelectViewController:self.viewControllers[self.selectedIndex]];
}
  • 点击旋转(自定义效果)
    在中间按钮的点击事件执行时旋转第二个index,然后执行旋转动画,
    在tabbar的代理事件中监听旋中中间按钮的事件,然后执行旋转动画,其他按钮则移除动画,代码如下
@interface BulgeTabBarController ()<MCTabBarControllerDelegate>

@end

@implementation BulgeTabBarController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //选中时的颜色
    self.mcTabbar.tintColor = [UIColor colorWithRed:251.0/255.0 green:199.0/255.0 blue:115/255.0 alpha:1];
    //透明设置为NO,显示白色,view的高度到tabbar顶部截止,YES的话到底部
    self.mcTabbar.translucent = NO;
    
    self.mcTabbar.position = MCTabBarCenterButtonPositionBulge;
    self.mcTabbar.centerImage = [UIImage imageNamed:@"tabbar_add_yellow"];
    self.mcDelegate = self;
    [self addChildViewControllers];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    
}

//添加子控制器
- (void)addChildViewControllers{
    //图片大小建议32*32
    [self addChildrenViewController:[[ViewController alloc] init] andTitle:@"首页" andImageName:@"tab1"];
    [self addChildrenViewController:[[ViewController alloc] init] andTitle:@"应用" andImageName:@"tab2"];
    //中间这个不设置东西,只占位
    [self addChildrenViewController:[[ViewController alloc] init] andTitle:@"发布" andImageName:@""];
    [self addChildrenViewController:[[ViewController alloc] init] andTitle:@"消息" andImageName:@"tab3"];
    [self addChildrenViewController:[[ViewController alloc] init] andTitle:@"我的" andImageName:@"tab4"];
}

- (void)addChildrenViewController:(UIViewController *)childVC andTitle:(NSString *)title andImageName:(NSString *)imageName{
    childVC.tabBarItem.image = [UIImage imageNamed:imageName];
    // 选中的颜色由tabbar的tintColor决定
    childVC.tabBarItem.selectedImage =  [UIImage imageNamed:imageName];
    childVC.title = title;
    
    BaseNavigationController *baseNav = [[BaseNavigationController alloc] initWithRootViewController:childVC];
    [self addChildViewController:baseNav];
}

- (void)mcTabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{
    if (tabBarController.selectedIndex == 2){
        [self rotationAnimation];
    }else {
        [self.mcTabbar.centerBtn.layer removeAllAnimations];
    }
}

//旋转动画
- (void)rotationAnimation{
    if ([@"key" isEqualToString:[self.mcTabbar.centerBtn.layer animationKeys].firstObject]){
        return;
    }
    CABasicAnimation *rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
    rotationAnimation.toValue = [NSNumber numberWithFloat:M_PI*2.0];
    rotationAnimation.duration = 3.0;
    rotationAnimation.repeatCount = HUGE;
    [self.mcTabbar.centerBtn.layer addAnimation:rotationAnimation forKey:@"key"];
}

  • 其他
    这里写了BaseNavigationController继承自UINavigationController,处理了push后隐藏底部UITabBar的情况,并解决了iPhonX上push时UITabBar上移的问题。

最后,再次附上Demo地址,如果对你有所帮助,不要吝啬你的Star✨哦!MCTabBarController

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