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iOS左右滑动切换/滑动标签页导航的设计思路

iOS中左右滑动切换，滑动标签页导航的设计思路。iOS开发中经常，几乎每个APP都含有这样的页面吧，几乎！UI设计师也都是这样抄来抄去…..

估计很多人都会说，直接用第三方就可以了，很多人封装过，很好用。而且这样的页面用第三方2分钟搞定，省时省力。

第三方

笔者也曾用过第三方，但是屡屡出bug。而且不好修改。所以只能自己写，bug少，代码通俗易懂，童叟无欺。

这里介绍一个第三方DLSlideView，Github地址： https://github.com/agdsdl/DLSlideView ，目前达到200多个star。但是中间出了一次bug，说是tableView左滑动删除有问题，后来这个原作者更新了版本，修复了这个bug。但是我使用的过程中又发现一个新bug，就是里面放UIScrollView的时候也有问题。

所以此文章不对代码进行封装，仅提供思路和代码。这样才能真正适配光大开发者（授之以鱼不如授之以渔），因为笔者认为每个页面都有不同，我们需要掌握思路，这样万变不离其宗，任何复杂的UI页面都可以用这个思路去写出来。下面我们来实现这样的一个比较时髦的效果，在导航上面加三个tab（其实就是三个button），支持手势切换，支持点击tab切换。

iOS左右滑动切换/滑动标签页导航的设计思路

理论分析

先观察这个效果图，三个UIButton和一个滑动的UILabel，UILabel给一个动画，让他的frame跟随某一个UIButton就可以了。至于跟踪哪个UIButton，当然是点击到的那个UIButton了，那么没点击只是滑动怎么办？UIScrollView的代理里面获取当前获得焦点的UIButton就可以了。三个UIButton分别对应不同的页面，每个页面可能逻辑很多很复杂，这样的话如果写在一个VC里面就显得臃肿了，我们要想办法分离代码，易于维护，并把逻辑分离，这样的话，就要对应3个ViewController。既然支持手势滑动，我们想到的就是UIScrollView，它有分页效果，很6 很87。我们可以把三个vc中的view拿出来，分别贴到UIScrollView上面去（就是addSubView）。理论到此完毕，下面上代码。

代码实现

我们要在HomeViewController里面放一个UIScrollView，然后初始化三个VC，分别拿到三个VC.view,最后把VC.view贴到UIScrollView上面，实现UIScrollView的分页滑动。

iOS左右滑动切换/滑动标签页导航的设计思路

 
#import "HomeViewController.h"
#import "NearbyViewController.h"
#import "SquareViewController.h"
#import "RecommendViewController.h"
 
@interface HomeViewController ()<UIActionSheetDelegate,UIScrollViewDelegate>{
    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 = [UIButtonbuttonWithType:UIButtonTypeCustom];
    nearbyBtn.frame = CGRectMake(0, 0, kScreenWidth/4, navView.frame.size.height);
    nearbyBtn.titleLabel.font = [UIFontboldSystemFontOfSize:19];
    [nearbyBtnaddTarget:selfaction:@selector(sliderAction:)forControlEvents:UIControlEventTouchUpInside];
    [nearbyBtnsetTitle:@"附近"forState:UIControlStateNormal];
    nearbyBtn.tag = 1;
    [navViewaddSubview:nearbyBtn];
        
        
    squareBtn = [UIButtonbuttonWithType: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 = [UIFontsystemFontOfSize:16];
    [squareBtnaddTarget:selfaction:@selector(sliderAction:)forControlEvents:UIControlEventTouchUpInside];
    [squareBtnsetTitle:@"广场"forState:UIControlStateNormal];
    squareBtn.tag = 2;
    [navViewaddSubview:squareBtn];
        
        
    recommendBtn = [UIButtonbuttonWithType: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 = [UIFontsystemFontOfSize:16];
    [recommendBtnaddTarget:selfaction:@selector(sliderAction:)forControlEvents:UIControlEventTouchUpInside];
    [recommendBtnsetTitle:@"推荐"forState:UIControlStateNormal];
    recommendBtn.tag = 3;
    [navViewaddSubview:recommendBtn];
        
        
    sliderLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 40-2, kScreenWidth/4, 4)];
    sliderLabel.backgroundColor = kBackgroundColor;
    [navViewaddSubview:sliderLabel];
    self.navigationItem.titleView = navView;
    leftButton = [[UIBarButtonItem alloc]initWithTitle:@"筛选"style:UIBarButtonItemStylePlaintarget:selfaction:@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.viewaddSubview: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)];
        [pageViewaddSubview:views[i]];
        [mainScrollViewaddSubview: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{
    [selfsliderAnimationWithTag:sender.tag];
    [UIViewanimateWithDuration:0.3animations:^{
        mainScrollView.contentOffset = CGPointMake(kScreenWidth* (sender.tag - 1), 0);
    }completion:^(BOOL finished) {
        
    }];
}
 
-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
    double index_ = scrollView.contentOffset.x / kScreenWidth;
    [selfsliderAnimationWithTag:(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 = [selfbuttonWithTag:tag];
    sender.selected = YES;
    //动画
    [UIViewanimateWithDuration:0.3animations:^{
        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 = [UIFontsystemFontOfSize:16];
        squareBtn.titleLabel.font = [UIFontsystemFontOfSize:16];
        recommendBtn.titleLabel.font = [UIFontsystemFontOfSize:16];
    
        sender.titleLabel.font = [UIFontboldSystemFontOfSize:19];
    }]; 
}
    
@end

好，思路和代码都有了。可以自己去实现了，真的不难，真的不需要用第三方。其实我本可以封装一个给大家用的，但是我没有封装，目的是让每个iOS都能对付UI设计师的这样的页面设计！！

另外博主维护一个iOS开发技术支持群：487599875，进群必须改名，群名片格式：城市-iOS-名字，例如广州-iOS-文明。