iOS开发—纯代码手写(不依靠第三方)实现顶部可滑动标题栏切换控制器

效果图：



实现：
创建UIView的分类UIView+SetMyView，在UIView+SetMyView.m里

#import "UIView+SetMyView.h"
@implementation UIView (SetMyView)
-(CGSize)gf_size{    return self.frame.size;}
-(void)setGf_size:(CGSize)gf_size{    CGRect rect = self.frame;    rect.size = gf_size;    self.frame = rect;}

-(CGFloat)gf_height{    return self.frame.size.height;}
-(void)setGf_height:(CGFloat)gf_height{    CGRect rect = self.frame;    rect.size.height = gf_height;    self.frame = rect;}

-(CGFloat)gf_width{    return self.frame.size.width;}
-(void)setGf_width:(CGFloat)gf_width{    CGRect rect = self.frame;    rect.size.width = gf_width;    self.frame = rect;}

-(CGFloat)gf_x{    return self.frame.origin.x;}
-(void)setGf_x:(CGFloat)gf_x{    CGRect rect = self.frame;    rect.origin.x = gf_x;    self.frame = rect;}

-(CGFloat)gf_y{    return self.frame.origin.y;}
-(void)setGf_y:(CGFloat)gf_y{    CGRect rect = self.frame;    rect.origin.y = gf_y;    self.frame = rect;}

-(CGFloat)gf_centerX{    return self.center.x;}
-(void)setGf_centerX:(CGFloat)gf_centerX{    CGPoint point = self.center;    point.x = gf_centerX;    self.center = point;}

-(CGFloat)gf_centerY{    return self.center.y;}
-(void)setGf_centerY:(CGFloat)gf_centerY{    CGPoint point = self.center;    point.y = gf_centerY;    self.center = point;}
@end

创建自定义GFTitleButton继承于UIButton，在GFTitleButton.m里

#import "GFTitleButton.h"
@implementation GFTitleButton
-(instancetype)initWithFrame:(CGRect)frame{        if (self = [super initWithFrame:frame]) {        [self setTitleColor:[UIColor darkGrayColor] forState:UIControlStateNormal];        [self setTitleColor:[UIColor redColor] forState:UIControlStateSelected];    }        return self;}
@end

在相应Controller中

#import "ViewController.h"#import "UIView+SetMyView.h"#import "GFTitleButton.h"
@interface ViewController ()<UIScrollViewDelegate>{    UIScrollView* myScrollView;    UIView *titleView;//标题栏    GFTitleButton* selectedTitleButton;//当前选中的按钮    UIView *indicatorView;//底部指示器}
@end
@implementation ViewController
- (void)viewDidLoad {    [super viewDidLoad];        [self setUpChildViewControllers];        [self setUpScrollView];        [self setUpTitleView];}
//设置子控制器-(void)setUpChildViewControllers{    //全部 控制器    UIViewController* allVC = [UIViewController new];    allVC.view.backgroundColor = [UIColor redColor];    [self addChildViewController:allVC];    //视频 控制器    UIViewController* videoVC = [UIViewController new];    videoVC.view.backgroundColor = [UIColor orangeColor];    [self addChildViewController:videoVC];    //声音 控制器    UIViewController* soundVC = [UIViewController new];    soundVC.view.backgroundColor = [UIColor yellowColor];    [self addChildViewController:soundVC];    //图片 控制器    UIViewController* picVC = [UIViewController new];    picVC.view.backgroundColor = [UIColor greenColor];    [self addChildViewController:picVC];    //段子 控制器    UIViewController* jokeVC = [UIViewController new];    jokeVC.view.backgroundColor = [UIColor blueColor];    [self addChildViewController:jokeVC];}
//设置scrollView-(void)setUpScrollView{        myScrollView = [[UIScrollView alloc] init];    myScrollView.backgroundColor = [UIColor purpleColor];        myScrollView.delegate = self;    myScrollView.frame = self.view.bounds;    myScrollView.pagingEnabled = YES;    myScrollView.showsVerticalScrollIndicator = NO;    myScrollView.showsHorizontalScrollIndicator = NO;    [self.view addSubview:myScrollView];        myScrollView.contentSize = CGSizeMake(self.view.gf_width * self.childViewControllers.count, 0);}
//添加标题栏titleView-(void)setUpTitleView{        titleView = [[UIView alloc] init];    titleView.backgroundColor = [[UIColor whiteColor]colorWithAlphaComponent:0.8];    titleView.frame = CGRectMake(0, 64 , self.view.gf_width, 35);    [self.view addSubview:titleView];        NSArray *titles = @[@"全部",@"视频",@"声音",@"图片",@"段子"];    NSInteger count = titles.count;        CGFloat titleButtonW = titleView.gf_width / count;    CGFloat titleButtonH = titleView.gf_height;        for (NSInteger i = 0;i < count; i++) {                GFTitleButton* titleButton = [GFTitleButton buttonWithType:UIButtonTypeCustom];                titleButton.tag = i; //绑定tag        [titleButton addTarget:self action:@selector(titelClick:) forControlEvents:UIControlEventTouchUpInside];        [titleButton setTitle:titles[i] forState:UIControlStateNormal];        CGFloat titleX = i * titleButtonW;        titleButton.frame = CGRectMake(titleX, 0, titleButtonW, titleButtonH);                [titleView addSubview:titleButton];    }    //第一个按钮    GFTitleButton *firstTitleButton = titleView.subviews.firstObject;    //底部指示器    indicatorView = [[UIView alloc]init];    indicatorView.backgroundColor = [firstTitleButton titleColorForState:UIControlStateSelected];        indicatorView.gf_height = 2;    indicatorView.gf_y = titleView.gf_height - indicatorView.gf_height;        [titleView addSubview:indicatorView];        [firstTitleButton.titleLabel sizeToFit];    indicatorView.gf_width = firstTitleButton.titleLabel.gf_width;    indicatorView.gf_centerX = firstTitleButton.gf_centerX;    //默认选中第一个按钮    [self scrollViewDidEndScrollingAnimation:myScrollView];}
//标题栏按钮点击-(void)titelClick:(GFTitleButton *)sender{    selectedTitleButton.selected = NO;    sender.selected = YES;    selectedTitleButton = sender;        //指示器    [UIView animateWithDuration:0.25 animations:^{                indicatorView.gf_width = sender.titleLabel.gf_width;        indicatorView.gf_centerX = sender.gf_centerX;    }];        //让myScrollView滚动    CGPoint offset = myScrollView.contentOffset;    offset.x = myScrollView.gf_width * sender.tag;    [myScrollView setContentOffset:offset animated:YES];}

#pragma mark - UIScrollViewDelegate//滚动完毕就会调用(不是人为拖拽scrollView导致滚动完毕，才会调用这个方法)-(void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView{        [self jumpToChildViewController];}
//跳转到相应的控制器-(void)jumpToChildViewController{        NSInteger index = myScrollView.contentOffset.x / myScrollView.gf_width;    //取出子控制器    UIViewController *childVc = self.childViewControllers[index];        if (childVc.view.superview) {        return;//如果这个子控制器已经添加过了，就直接返回    }    childVc.view.frame = CGRectMake(index * myScrollView.gf_width, 0, myScrollView.gf_width, myScrollView.gf_height);    [myScrollView addSubview:childVc.view];}
//滚动完毕就会调用（如果是人为拖拽scrollView导致滚动完毕，才会调用这个方法）-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{        NSInteger index = scrollView.contentOffset.x / scrollView.gf_width;    GFTitleButton *titleButton = titleView.subviews[index];    [self titelClick:titleButton]; [self jumpToChildViewController];}
@end