iOS 修改TabBar的item间距

@interface HPTabBarController ()<UITabBarControllerDelegate>//继承自UITabBarController

@property (nonatomic, strong) HPMapViewController *mapViewController;
@property (nonatomic, strong) HPPGCListViewController *PGCListViewController;
@property (nonatomic, strong) HPLonelyShopViewController *lonelyShopVC;
@property (nonatomic, strong) HPPickerViewController *pickerViewController;
@property (nonatomic, strong) HPMessageListViewController *messageViewController;
@property (nonatomic, strong) HPProfileViewController *profileViewController;
@end

@implementation HPTabBarController

-(void)viewWillLayoutSubviews { // 修改Tabbar的高度
    CGRect tabFrame =self.tabBar.frame;
    CGFloat TABBAR_HEIGHT =  + ;
    tabFrame.size.height= TABBAR_HEIGHT;
    tabFrame.origin.y= self.view.frame.size.height- TABBAR_HEIGHT;
    self.tabBar.frame= tabFrame;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.viewControllers = [self tabBarControllers];
    UIView *topLine = [[UIView alloc]initWithFrame:CGRectMake(, , SCREEN_WIDTH, 0.5)];
    topLine.backgroundColor = [UIColor clearColor];
    [self.tabBar addSubview:topLine];

    UIImage *bgClearImg = [UIImage imageWithColor:[UIColor colorWithRed:/255.0 green:/255.0 blue:/255.0 alpha:0.94/1.0]];
    self.tabBar.backgroundImage = [UIImage imageNamed:@"shadows_@3x"];//bgClearImg;

    [self.tabBar.items enumerateObjectsUsingBlock:^(UITabBarItem * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        if (idx == ) { //修改tabbar的间距
            [obj setImageInsets:UIEdgeInsetsMake(-, , -, -)];
        }else if (idx == ) {
            [obj setImageInsets:UIEdgeInsetsMake(, -, , )];
        }
        obj.tag = idx;
    }];
    self.selectedIndex = ;
}

效果: