iOS-系统tabbar加选中条

-(void)viewDidAppear:(BOOL)animated{

    

    [super viewDidAppear:animated];

    

    UITabBar *tab = self.view.subviews[1];

    tab.layer.borderColor = [UIColor whiteColor].CGColor;

    UIView *wapperView = tab.subviews[0];

    wapperView.frame = CGRectMake(0,2, CGRectGetWidth(self.view.frame),48);

    

    UIView *v = [[UIView alloc] initWithFrame:CGRectMake(0, 0, CGRectGetWidth(self.view.frame)/4,2)];

    _slideView = v;

    v.backgroundColor = kGlobalColor;

    [tab addSubview:v];

    

    for (UIView *v in tab.subviews) {

        

        if ([v isMemberOfClass:[UIImageView class]]) {

//memberofclass是判断实例是否是给到的类实例化而来的对象，iskindofclass 是判断当前类是否是给到的类或者是它的子类实例化而来的

            [v removeFromSuperview];

            break;

        }

    }

}

-(void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{

    

    [UIView animateWithDuration:.35 animations:^{

        

        _slideView.frame = CGRectMake(CGRectGetWidth(_slideView.frame) *self.selectedIndex, CGRectGetMinY(_slideView.frame), CGRectGetWidth(_slideView.frame), CGRectGetHeight(_slideView.frame));

        

    }];

    

}

{

    __weak UIView *_slideView;

}