关于在TabBar 中添加按钮,并通过block 或代理在控制器中实现响应

#import <UIKit/UIKit.h>

typedef void(^myBlock) (NSArray *composeButton);//给block起别名,用数组来存放点击的Button

@interface ZSTabBar : UITabBar

@property (nonatomic,strong) myBlock composeButtonBlock;//定义block

@end

#import "ZSTabBar.h"

@interface ZSTabBar ()

@property (nonatomic,strong) UIButton *composeButton;//TabBar中间的撰写按钮

@end
@implementation ZSTabBar

-(instancetype)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    
    [self addSubview:self.composeButton];
    
    return  self;
}
//设置TabBar的子控件
-(void)layoutSubviews{
    [super layoutSubviews];
    
    CGFloat tabBarW = [UIScreen mainScreen].bounds.size.width / 5;
    
    int index = 0;
    
    UIView *tabbar = [[UIView alloc]init];
    
    for (tabbar in self.subviews) {
        //如果TabBar子控件类型是UITabBarButton,这里是判断的关键
        Class class = NSClassFromString(@"UITabBarButton");
        
        if ([tabbar isKindOfClass:class]) {

            //给类型属于UITabBarButton设置frame.高一定不能写0
            tabbar.frame = CGRectMake(tabBarW * index, 0, tabBarW, self.bounds.size.height);
            
            index ++;
            //因为中间的撰写按钮不属于UITabBarButton类,所以要另进行判断
            if (index == 2) {
                index ++;
            }
        }
    }
    
    self.composeButton.center = CGPointMake(self.frame.size.width / 2, self.frame.size.height / 2);
}


#pragma  mark -- 对撰写按钮懒加载
-(UIButton *)composeButton{
    if (_composeButton == nil) {
        _composeButton = [[UIButton alloc]init];
        //设置背景图
        [_composeButton setBackgroundImage:[UIImage imageNamed:@"tabbar_compose_button"] forState:UIControlStateNormal];
        
        [_composeButton setBackgroundImage:[UIImage imageNamed:@"tabbar_compose_button_highlighted"] forState:UIControlStateHighlighted];
        //设置图片
        [_composeButton setImage:[UIImage imageNamed:@"tabbar_compose_icon_add"] forState:UIControlStateNormal];
        [_composeButton setImage:[UIImage imageNamed:@"tabbar_compose_icon_add_highlighted"] forState:UIControlStateHighlighted];
        
        [_composeButton sizeToFit];
        
        //点击事件
        [_composeButton addTarget:self action:@selector(composeButtonClick:) forControlEvents:UIControlEventTouchUpInside];
        
    }
    return _composeButton;
}

#pragma mark --撰写按钮的点击事件

-(void)composeButtonClick: (UIButton *)send{
    //最好要判断一下block
    if (self.composeButtonBlock) {
        //将按钮添加到block中
        self.composeButtonBlock(@[send]);
    }
}

@end

#import "ZSMainFrameController.h"
#import "ZSHomeViewController.h"
#import "ZSDiscoveryViewController.h"
#import "ZSMessageViewController.h"
#import "ZSMineViewController.h"
#import "ZSTabBar.h"//自定义TabBar
@implementation ZSMainFrameController
    
-(void)viewDidLoad{
    [super viewDidLoad];
    
    self.view.backgroundColor = [UIColor whiteColor];
    
    ZSTabBar *tabBar = [[ZSTabBar alloc]init];
    //TabBar是ZSTabBar类中私有属性,通过KVC赋值  关键
    [self setValue:tabBar forKey:@"tabBar"];
    //自定义TabBar的block
    tabBar.composeButtonBlock = ^(NSArray *composeButton){
        //从数组取出Button
        UIButton *compoeButton = composeButton[0];
        //按钮的点击事件
        [self composeButtonClick:compoeButton];
    };
    
    ZSHomeViewController *homeVC = [[ZSHomeViewController alloc]init];
    [self addChildVC:homeVC title:@"首页" imageName:@"tabbar_home"];
    
    ZSMessageViewController *messageVC = [[ZSMessageViewController alloc]init];
    [self addChildVC:messageVC title:@"消息" imageName:@"tabbar_message_center"];
    
    ZSDiscoveryViewController *discoverVC = [[ZSDiscoveryViewController alloc]init];
    [self addChildVC:discoverVC title:@"发现" imageName:@"tabbar_discover"];
    
    ZSMineViewController *mineVC = [[ZSMineViewController alloc]init];
    [self addChildVC:mineVC title:@"我" imageName:@"tabbar_profile"];
    
    
    
}


#pragma  mark -- 添加子控制器
-(void)addChildVC:(UIViewController *)childVC title:(NSString *)title imageName:(NSString *)imageName{
    
    childVC.title = title;
    //未选中图片
    childVC.tabBarItem.image = [UIImage imageNamed:imageName];
    //选中图片
    NSString *selectedImageName = [NSString stringWithFormat:@"%@_selected",imageName];
    childVC.tabBarItem.selectedImage = [UIImage imageNamed:selectedImageName];
    
    UINavigationController *naVC = [[UINavigationController alloc]initWithRootViewController:childVC];
    
    [self addChildViewController:naVC];
    
    
}

#pragma mark -- 中间撰写按钮的点击事件
-(void)composeButtonClick:(UIButton *)send{
    在这里就可以实现撰写按钮的方法
}


@end