iOS如何设计左右滑动标签页导航

#import "HomeViewController.h"
#import "NearbyViewController.h"
#import "SquareViewController.h"
#import "RecommendViewController.h"
 
@interface HomeViewController (){
UIBarButtonItem *leftButton;
NearbyViewController *nearbyVC;
SquareViewController *squareVC;
RecommendViewController *recommendVC;
UIScrollView *mainScrollView;
UIView *navView;
UILabel *sliderLabel;
UIButton *nearbyBtn;
UIButton *squareBtn;
UIButton *recommendBtn;
}
 
@end
 
@implementation HomeViewController
 
//懒加载三个VC
-(NearbyViewController *)nearbyVC{
if (nearbyVC==nil) {
 nearbyVC = [[NearbyViewController alloc]init];
}
return nearbyVC;
}
 
-(SquareViewController *)squareVC{
if (squareVC==nil) {
 squareVC = [[SquareViewController alloc]init];
 
}
return squareVC;
}
 
 
-(RecommendViewController *)recommendVC{
if (recommendVC==nil) {
 recommendVC = [[RecommendViewController alloc]init];
 
}
return recommendVC;
}
//初始化三个UIBtton和一个滑动的UILabel，命名为sliderLabel，三个btn放倒一个UIView上面navView。
-(void)initUI{
 navView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, kScreenWidth, 40)];
nearbyBtn = [UIButton buttonWithType:UIButtonTypeCustom];
nearbyBtn.frame = CGRectMake(0, 0, kScreenWidth/4, navView.frame.size.height);
nearbyBtn.titleLabel.font = [UIFont boldSystemFontOfSize:19];
[nearbyBtn addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventTouchUpInside];
[nearbyBtn setTitle:@"附近" forState:UIControlStateNormal];
nearbyBtn.tag = 1;
[navView addSubview:nearbyBtn];
 
 
squareBtn = [UIButton buttonWithType:UIButtonTypeCustom];
squareBtn.frame = CGRectMake(nearbyBtn.frame.origin.x+nearbyBtn.frame.size.width, nearbyBtn.frame.origin.y, kScreenWidth/4, navView.frame.size.height);
squareBtn.titleLabel.font = [UIFont systemFontOfSize:16];
[squareBtn addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventTouchUpInside];
[squareBtn setTitle:@"广场" forState:UIControlStateNormal];
squareBtn.tag = 2;
[navView addSubview:squareBtn];
 
 
recommendBtn = [UIButton buttonWithType:UIButtonTypeCustom];
recommendBtn.frame = CGRectMake(squareBtn.frame.origin.x+squareBtn.frame.size.width, squareBtn.frame.origin.y, kScreenWidth/4, navView.frame.size.height);
recommendBtn.titleLabel.font = [UIFont systemFontOfSize:16];
[recommendBtn addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventTouchUpInside];
[recommendBtn setTitle:@"推荐" forState:UIControlStateNormal];
recommendBtn.tag = 3;
[navView addSubview:recommendBtn];
 
 
sliderLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 40-2, kScreenWidth/4, 4)];
sliderLabel.backgroundColor = kBackgroundColor;
[navView addSubview:sliderLabel];
self.navigationItem.titleView = navView;
leftButton = [[UIBarButtonItem alloc]initWithTitle:@"筛选" style:UIBarButtonItemStylePlain target:self action:@selector(leftBarButtonItemPressed:)];
leftButton.tintColor = [UIColor whiteColor];
self.navigationItem.leftBarButtonItem = leftButton;
 
}
 
-(UIButton *)theSeletedBtn{
if (nearbyBtn.selected) {
 return nearbyBtn;
}else if (squareBtn.selected){
 return squareBtn;
}else if (recommendBtn.selected){
 return recommendBtn;
}else{
 return nil;
 }
}
 
 
- (void)viewDidLoad {
[super viewDidLoad];
[self initUI];
[self setMainScrollView];
}
 //初始化UIScrollView
-(void)setMainScrollView{
mainScrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, kScreenWidth, kScreenHeight-kTabBarHeight)];
mainScrollView.delegate = self;
mainScrollView.backgroundColor = [UIColor whiteColor];
mainScrollView.pagingEnabled = YES;
mainScrollView.showsHorizontalScrollIndicator = NO;
mainScrollView.showsVerticalScrollIndicator = NO;
[self.view addSubview:mainScrollView];
NSArray *views = @[self.nearbyVC.view, self.squareVC.view,self.recommendVC.view];
for (int i = 0; i < views.count; i++){
 //添加背景，把三个VC的view贴到mainScrollView上面
 UIView *pageView = [[UIView alloc]initWithFrame:CGRectMake(kScreenWidth * i, 0, mainScrollView.frame.size.width, mainScrollView.frame.size.height)];
 [pageView addSubview:views[i]];
 [mainScrollView addSubview:pageView];
}
mainScrollView.contentSize = CGSizeMake(kScreenWidth * (views.count), 0);
}
-(UIButton *)buttonWithTag:(NSInteger)tag{
if (tag==1) {
 return nearbyBtn;
}else if (tag==2){
 return squareBtn;
}else if (tag==3){
 return recommendBtn;
}else{
 return nil;
}
}
-(void)sliderAction:(UIButton *)sender{
[self sliderAnimationWithTag:sender.tag];
[UIView animateWithDuration:0.3 animations:^{
 mainScrollView.contentOffset = CGPointMake(kScreenWidth * (sender.tag - 1), 0);
} completion:^(BOOL finished) {
 
}];
 
}
-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
double index_ = scrollView.contentOffset.x / kScreenWidth;
[self sliderAnimationWithTag:(int)(index_+0.5)+1];
}
#pragma mark - sliderLabel滑动动画
- (void)sliderAnimationWithTag:(NSInteger)tag{
nearbyBtn.selected = NO;
squareBtn.selected = NO;
recommendBtn.selected = NO;
UIButton *sender = [self buttonWithTag:tag];
sender.selected = YES;
//动画
[UIView animateWithDuration:0.3 animations:^{
 sliderLabel.frame = CGRectMake(sender.frame.origin.x, sliderLabel.frame.origin.y, sliderLabel.frame.size.width, sliderLabel.frame.size.height);
 
} completion:^(BOOL finished) {
 nearbyBtn.titleLabel.font = [UIFont systemFontOfSize:16];
 squareBtn.titleLabel.font = [UIFont systemFontOfSize:16];
 recommendBtn.titleLabel.font = [UIFont systemFontOfSize:16];
 
 sender.titleLabel.font = [UIFont boldSystemFontOfSize:19];
}];
 
}
 
@end