自定义tabBar（适用于有选中图片随着移动的情况）

#import "RootTabBarController.h"
#import "HomeViewController.h"
#import "NewsViewController.h"
#import "TopViewController.h"
#import "MoreViewController.h"
#import "MovieViewController.h"


#define screenW [UIScreen mainScreen].bounds.size.width
#define nameLableTextFont [UIFont systemFontOfSize:10]




@interface RootTabBarController ()
{
    UIImageView *_selectImg;
}


@end

@implementation RootTabBarController

- (void)viewDidLoad {
    [super viewDidLoad];

    //1. 创建视图
    [self creatVC];
   
    //2. 自定义标签栏
    [self creatTabBar];
   
   
}

//1. 创建控制器
- (void)creatVC
{
    //1. 创建视图控制器
    HomeViewController *firstCtrl = [[HomeViewController alloc] init];
    NewsViewController *secondCtrl = [[NewsViewController alloc] init];
    TopViewController *thirdCtrl = [[TopViewController alloc] init];
    MovieViewController *forthCtrl = [[MovieViewController alloc] init];
    MoreViewController *fifthCtrl = [[MoreViewController alloc] init];
   
   
   
    NSArray *viewCtrls = @[firstCtrl,secondCtrl,thirdCtrl,forthCtrl,fifthCtrl];
   
    //2. 创建导航控制器
    NSMutableArray *navCtrls = [[NSMutableArray alloc] init];
   
    //导航栏标题
    NSArray *navigationTitle = @[@"北美榜", @"新闻", @"TOP250", @"影院", @"更多"];
   
    for (int i=0; i<viewCtrls.count; i++) {
      
        //2.1 取得视图控制器
        UIViewController *viewCtrl = viewCtrls[i];
       
        UINavigationController *navCtrl = [[UINavigationController alloc] initWithRootViewController:viewCtrl];
       
        //2.2.设置导航栏背景图片
        [navCtrl.navigationBar setBackgroundImage:[UIImage imageNamed:@"nav_bg_all-64@2x"] forBarMetrics:UIBarMetricsDefault];
       
        //1.设置导航栏标题
        viewCtrl.title = navigationTitle[i];
        NSDictionary *dic = @{
                              NSFontAttributeName:[UIFont systemFontOfSize:18],
                              NSForegroundColorAttributeName:[UIColor whiteColor]
                              };
        [viewCtrl.navigationController.navigationBar setTitleTextAttributes:dic];
       
       
        //2.2 将导航控制器存入数组
        [navCtrls addObject:navCtrl];
    }
   
    //3.交给标签控制器管理
    self.viewControllers = navCtrls;
   
   
}

//2. 自定义标签栏
- (void)creatTabBar
{
    //1. 取得标签栏上得子空间
    NSArray *array = self.tabBar.subviews;
   
    //2. 循环删除子控件
    for (UIView *sub in array) {
      
        //2.1 判断是否属于UITabBarButton这个类
       Class class = NSClassFromString(@"UITabBarButton");
       
        //2.2 如果属于这个类就删除
        if ([sub isKindOfClass:class]) {
           
            [sub removeFromSuperview];
        }
    }
   
    //3. 设置tabBar背景图片
    self.tabBar.backgroundImage = [UIImage imageNamed:@"tab_bg_all"];
   
    //4. 添加按钮
    //4.1 定义按钮图像和文字数组
    NSArray *btnImageArray = @[@"movie_home", @"msg_new", @"start_top250", @"icon_cinema", @"more_setting"];
    NSArray *nameLableArray = @[@"首页", @"新闻", @"TOP", @"电影", @"更多"];
   
    CGFloat width = screenW / btnImageArray.count;
   
    //5. 循环添加按钮
    for (int i = 0; i < btnImageArray.count; i++) {
       
//        5.1 添加tabBar最底层view
        CGFloat backViewW = 45;
        CGFloat backViewH = self.tabBar.bounds.size.height;
        CGFloat backViewX = (width-40) * 0.5 + width * i;
        CGFloat backViewY = 0;
      
        UIView *backView = [[UIView alloc] init];
        backView.frame = CGRectMake(backViewX, backViewY, backViewW, backViewH);
       
       
//        5.2 添加按钮图片
        CGFloat tabBarItemImageW = 20;
        CGFloat tabBarItemImageH = 20;
        CGFloat tabBarItemImageX = (backViewW - tabBarItemImageW) * 0.5;
        CGFloat tabBarItemImageY = 5;
        UIImageView *tabBarItemImage = [[UIImageView alloc] init];
        tabBarItemImage.frame = CGRectMake(tabBarItemImageX, tabBarItemImageY, tabBarItemImageW, tabBarItemImageH);
      
        tabBarItemImage.contentMode = UIViewContentModeScaleAspectFit;

        tabBarItemImage.image = [UIImage imageNamed:btnImageArray[i]];;
        [backView addSubview:tabBarItemImage];
       
//        5.3 添加lable
        CGFloat nameLableX = 0;
        CGFloat nameLableY = tabBarItemImageH;
        CGFloat nameLableW = backViewW;
        CGFloat nameLableH = backViewH - tabBarItemImageH;
        UILabel *nameLable = [[UILabel alloc] init];
        nameLable.textColor = [UIColor whiteColor];
        nameLable.text = nameLableArray[i];
        nameLable.textAlignment = NSTextAlignmentCenter;
        nameLable.frame = CGRectMake(nameLableX, nameLableY, nameLableW, nameLableH);
        [backView addSubview:nameLable];
        nameLable.font = nameLableTextFont;
     
//        5.4 将背景view添加到tabbar
        [self.tabBar addSubview:backView];
       
//        5.5 添加大按钮
        UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
        btn.frame = backView.bounds;
        [backView addSubview:btn];
       
        btn.tag = i;
       
        //添加点击事件
        [btn addTarget:self action:@selector(buttonAction:) forControlEvents:UIControlEventTouchUpInside];

    }
   
    //5.添加选中图标
    CGFloat imgW = 45;
    CGFloat imgH = self.tabBar.bounds.size.height;
    CGFloat imgX = (width-40) * 0.5 ;
    CGFloat imgY = 0;
    _selectImg = [[UIImageView alloc] init];
    _selectImg.image = [UIImage imageNamed:@"selectTabbar_bg_all1"];
    _selectImg.frame = CGRectMake(imgX, imgY, imgW, imgH);
   
    [self.tabBar addSubview:_selectImg];
    [self.tabBar sendSubviewToBack:_selectImg];
  
   
}

#pragma mark - 按钮点击事件

- (void)buttonAction:(UIButton *)button {
   
    //切换视图控制器
    NSInteger tag = button.tag;
    self.selectedIndex = tag;
   
    [UIView animateWithDuration:.35 animations:^{
        //切换_selectImg的位置
       
        _selectImg.center = button.superview.center;
       
    }];
}#import "RootTabBarController.h"
#import