#import <UIKit/UIKit.h>@interface WSTabBar : UITabBar@end#import "WSTabBar.h"@implementation WSTabBar- (instancetype)initWithFrame:(CGRect)frame
{if (self = [super initWithFrame:frame]) {// 初始化操作
    }return self;
}- (void)layoutSubviews
{[super layoutSubviews];// 布局子控件for (UITabBarItem *item in self.subviews) {
//        item.title = @"标题";
//        item.image = [UIImage imageNamed:@""];
    }}
@end

// UITabBarController中设置自定义tabBar
- (void)setupTabBar
{
//    self.tabBar = [[WSTabBar alloc] init]; // 不能直接赋值，只能通过KVC方式设置tabBar[self setValue:[[WSTabBar alloc] init] forKeyPath:@"tabBar"];
}

#import <UIKit/UIKit.h>
@class WSTabBar;@protocol WSTabBarDelegate <NSObject>
/** 控制器遵守该协议后，用于传递tabBar当前选中的按钮的索引给控制器 */
- (void)tabBar:(WSTabBar *)tabBar withSelectedIndex:(NSInteger)selectedIndex;@end@interface WSTabBar : UIView
/** tabBar的item数组 */
@property (nonatomic,strong) NSArray *items;
/** tabBar所属的tabBarController */
@property (nonatomic,strong) UITabBarController *tabBarController;/** block */
@property (nonatomic,strong) void(^selectedIndexBlock)(NSInteger);// 代理
@property (nonatomic,weak) id<WSTabBarDelegate> delegate;@end#import "WSTabBar.h"@interface WSTabBar ()
/** 当前选中的按钮 */
@property(nonatomic,strong) UIButton *selectedBtn;@end@implementation WSTabBar
//- (instancetype)initWithFrame:(CGRect)frame
//{
//    if (self = [super initWithFrame:frame]) {
//
//    }
//
//    return self;
//}- (void)setItems:(NSArray *)items
{_items = items; // 千万不要漏掉这一句啊！漏掉后，会导致_items为nilNSInteger index = 0;for (UITabBarItem *item in items) {UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];[btn setBackgroundImage:item.image forState:UIControlStateNormal];[btn setBackgroundImage:item.selectedImage forState:UIControlStateSelected];btn.tag = index;++index;[btn addTarget:self action:@selector(btnDidOnClick:) forControlEvents:UIControlEventTouchUpInside];[self addSubview:btn];}
}- (void)layoutSubviews
{[super layoutSubviews];for (int i = 0; i < self.items.count; i++) {UIButton *btn = self.subviews[i];CGFloat width = self.frame.size.width / self.items.count;CGFloat height = self.frame.size.height;btn.frame = CGRectMake(i * width, 0, width, height);}
}
- (void)btnDidOnClick:(UIButton *)btn
{// 三部曲self.selectedBtn.selected = NO; // 上一个按钮取消选中btn.selected = YES; // 当前按钮设置选中self.selectedBtn = btn; // 当前按钮赋值给selectedBtn// 5种方法// 1.tabBarController属性/*self.tabBarController.selectedIndex = btn.tag;*/// 2.通知/*NSMutableDictionary *dict = [NSMutableDictionary dictionary];dict[@"selectedIndex"] = @(btn.tag);[[NSNotificationCenter defaultCenter] postNotificationName:@"changeSelectedIndexNotification" object:self userInfo:dict];*/// 3.KVO 控制器或者tabBar监听selectedBtn.tag的变化// 4.block/*if (self.selectedIndexBlock) {self.selectedIndexBlock(btn.tag);}*/// 5.代理if ([self.delegate respondsToSelector:@selector(tabBar:withSelectedIndex:)]) {[self.delegate tabBar:self withSelectedIndex:btn.tag];}
}- (void)dealloc
{}

#import <UIKit/UIKit.h>@interface WSTabBarController : UITabBarController@end#import "WSTabBarController.h"
#import "WSTabBar.h"
#import "OneChildViwController.h"
#import "TwoChildViwController.h"
#import "ThreeChildViwController.h"
#import "FourChildViwController.h"
#import "FiveChildViwController.h"@interface WSTabBarController ()<WSTabBarDelegate>
@property(nonatomic,strong) NSMutableArray *items;
@property(nonatomic,strong) WSTabBar *WSTabBar;@end@implementation WSTabBarController- (NSMutableArray *)items
{if (!_items) {_items = [NSMutableArray array];}return _items;
}- (void)viewDidLoad {[super viewDidLoad];[self setupChildVC];[self setupTabBar];// 2.注册监听通知
//    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeSelectedIndex:) name:@"changeSelectedIndexNotification" object:nil];//    // 3.KVO
//    [self addObserver:self forKeyPath:@"WSTabBar.selectedBtn.tag" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil];
}- (void)changeSelectedIndex:(NSNotification *)noti
{self.selectedIndex = [noti.userInfo[@"selectedIndex"] integerValue];
}- (void)dealloc
{// 移除通知监听
    [[NSNotificationCenter defaultCenter] removeObserver:self];// 移除KVO监听[self removeObserver:self forKeyPath:@"WSTabBar.selectedBtn.tag"];
}
- (void)setupChildVC
{OneChildViwController *oneVC = [[OneChildViwController alloc] init];TwoChildViwController *twoVC = [[TwoChildViwController alloc] init];ThreeChildViwController *threeVC = [[ThreeChildViwController alloc] init];FourChildViwController *fourVC = [[FourChildViwController alloc] init];FiveChildViwController *fiveVC = [[FiveChildViwController alloc] init];[self setupChildVC:oneVC image:@"TabBar_Arena_new" selectedImage:@"TabBar_Arena_selected_new" title:@"竞技场"];[self setupChildVC:twoVC image:@"TabBar_Discovery_new" selectedImage:@"TabBar_Discovery_selected_new" title:@"发现"];[self setupChildVC:threeVC image:@"TabBar_History_new" selectedImage:@"TabBar_History_selected_new" title:@"开奖信息"];[self setupChildVC:fourVC image:@"TabBar_LotteryHall_new" selectedImage:@"TabBar_LotteryHall_selected_new" title:@"购彩大厅"];[self setupChildVC:fiveVC image:@"TabBar_MyLottery_new" selectedImage:@"TabBar_MyLottery_selected_new" title:@"我的彩票"];}- (void)setupChildVC:(UIViewController *)childVC image:(NSString *)image selectedImage:(NSString *)selectedImage title:(NSString *)title
{UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:childVC];childVC.tabBarItem.image = [UIImage imageNamed:image];childVC.tabBarItem.selectedImage = [UIImage imageNamed:selectedImage];childVC.tabBarItem.title = title;[self.items addObject:childVC.tabBarItem];[self addChildViewController:nav];
}- (void)setupTabBar
{WSTabBar *tabBar = [[WSTabBar alloc] init];tabBar.frame = CGRectMake(0, [UIScreen mainScreen].bounds.size.height - 49, [UIScreen mainScreen].bounds.size.width, 49);// iphone 4、5、6 tabBar高度为49// iPhone 4、5、6 UINavigationBar高度为44// iphone 4、5、6 UINavigationBarBackGround高度为64 所以会有状态栏被导航栏同化的现象
    tabBar.items = self.items; // 不能 tabBar.items = self.tabBar.items;
    tabBar.backgroundColor = [UIColor orangeColor];[self.view addSubview:tabBar];// 1.WSTabBar的tabBarController属性
//     tabBar.tabBarController = self;// 3.KVO(tabBar监听)
//    [tabBar addObserver:self forKeyPath:@"selectedBtn.tag" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil];// 3.KVO(让控制器监听)
//    self.WSTabBar = tabBar;
//    [self addObserver:self forKeyPath:@"WSTabBar.selectedBtn.tag" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil];// 4.block方式
//    tabBar.selectedIndexBlock = ^(NSInteger selectedIndex){
//        self.selectedIndex = selectedIndex;
//    };// 5.代理tabBar.delegate = self;}// KVO监听到键值变化
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context
{NSInteger new = [change[NSKeyValueChangeNewKey] integerValue];self.selectedIndex = new;
}- (void)viewWillAppear:(BOOL)animated
{[super viewWillAppear:animated];for (UIView *subView in self.tabBar.subviews) {if (![subView isKindOfClass:[WSTabBar class]]) {// 移除原生tabBar上的item
            [subView removeFromSuperview];}}
}#pragma mark - WSTabBarDelegate
- (void)tabBar:(WSTabBar *)tabBar withSelectedIndex:(NSInteger)selectedIndex
{self.selectedIndex = selectedIndex;
}
@end