iOS 自定义滑动切换TabbarItem 觉得设计丑也要做出来的UI效果。。。

- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UINavigationController *)viewController
{
    UIViewController *vc = viewController.viewControllers.firstObject;
    NSInteger tag = vc.tabBarItem.tag;
    NSLog(@"点击了 第 %ld 个 tab",tag);//tag来自于视图初始化时候的赋值
}

- (UIViewController *)mineVC
{
    if (!_mineVC) {
        _mineVC = [[UIViewController alloc]init];
        NSString *title = nil;
        _mineVC.tabBarItem = [[UITabBarItem alloc] initWithTitle:title image:nil selectedImage:nil];
        _mineVC.tabBarItem.tag = 2;//这里对不同的视图的根控制器进行标记区分
        _mineVC.view.backgroundColor = [UIColor redColor];
    }
    return _mineVC;
}

 //显示是在主界面上的视图控制器显示tabbar其他情况都隐藏，处理方案：
 //在视图控制器基类HFBaseViewController里对tabbar做显示隐藏的逻辑判断，并在交互过程自然显示隐藏不突兀处理

#import <UIKit/UIKit.h>

@interface HFBaseViewController : UIViewController

@end
//////////

@interface HFBaseViewController ()

@end

@implementation HFBaseViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor colorWithConfigKey:@"bg_white"];
    if (!self.fd_prefersNavigationBarHidden) {
        [self setDefaultBackButtonItem];
    }
    if (@available(iOS 11.0, *)) {
        [UIScrollView appearance].contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
    } else {
        self.automaticallyAdjustsScrollViewInsets = NO;
    }
    self.edgesForExtendedLayout = UIRectEdgeNone; //防止tabbar遮挡视图
}

#pragma mark - 显示tabbar动画
- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];if ([FIRWalletHomeVC isTypeLegal:self]
     || [FIRMarketVC isTypeLegal:self]
     || [FIRMineVC isTypeLegal:self]) {
        self.tabBarController.tabBar.alpha = 1.0;
        self.tabBarController.tabBar.hidden = NO;
        return ;
    }
    [UIView animateWithDuration:0.5 animations:^{
        self.tabBarController.tabBar.alpha = 0.0;
        self.tabBarController.tabBar.hidden = YES;
    } completion:^(BOOL finished) {
        //none  
    }];

}