iOS 仿网易新闻结构

1.首页效果

2.滑动过程中颜色渐变，文字缩放

3.滑动结束边缘标题自动适当居中

实现代码：

////  ViewController.m//  网易新闻////  Created by llkj on 2017/11/20.//  Copyright © 2017年 LayneCheung. All rights reserved.//#import "ViewController.h"#import "TopLineViewController.h"#import "HotViewController.h"#import "VideoViewController.h"#import "SocietyViewController.h"#import "TechViewController.h"#import "ReadViewController.h"#define ScreenW [UIScreen mainScreen].bounds.size.width#define ScreenH [UIScreen mainScreen].bounds.size.height@interface ViewController ()<UIScrollViewDelegate>/** 标题scrollView */@property (nonatomic, weak) UIScrollView *titleScrollView;/** 内容scrollView */@property (nonatomic, weak) UIScrollView *contentScrollView;/** 标题数组 */@property (nonatomic, strong) NSArray *titles;/** 上一次点击选中的按钮 */@property (nonatomic, weak) UIButton *previousClickButton;/** 保存所有标题按钮的数组 */@property (nonatomic, strong) NSMutableArray *titleButtons;@end@implementation ViewController#pragma mark - 懒加载- (NSMutableArray *)titleButtons {    if (_titleButtons == nil) {        _titleButtons = [NSMutableArray array];    }    return _titleButtons;}- (NSArray *)titles {    if (_titles == nil) {        _titles = @[@"头条", @"热点", @"视频", @"社会", @"订阅", @"科技",];    }    return _titles;}- (void)viewDidLoad {    [super viewDidLoad];    self.navigationItem.title = @"网易新闻";    //1.添加标题滚动视图    [self setupTitleScrollView];    //2.添加内容滚动视图    [self setupContentScrollView];    //3.添加所有子控制器    [self setupAllChildVC];    //4.设置所有标题    [self setupAllTitle];}#pragma mark - <UIScrollViewDelegate>//滚动完成调用- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {    //获取当前角标    NSInteger i = scrollView.contentOffset.x / scrollView.frame.size.width;    //获取标题按钮    UIButton *titleButton = self.titleButtons[i];    //1.选中标题    [self selectedButton:titleButton];    //2.把对应子控制器的View添加上去    [self addOneViewController:i];}- (void)scrollViewDidScroll:(UIScrollView *)scrollView {    //字体缩放    //1.获得左边按钮    NSInteger leftI = scrollView.contentOffset.x / ScreenW;;    UIButton *leftButton = self.titleButtons[leftI];    //2.获得右边按钮    NSInteger rightI = leftI + 1;    UIButton *rightButton;    if (rightI < self.titleButtons.count) {        rightButton = self.titleButtons[rightI];    }    // 0 ~ 1 => 1 ~ 1.2    CGFloat scaleR = scrollView.contentOffset.x / ScreenW;    scaleR -= leftI;    CGFloat scaleL = 1 - scaleR;    //3.缩放按钮    leftButton.transform = CGAffineTransformMakeScale(scaleL * 0.2 + 1, scaleL * 0.2 + 1);    rightButton.transform = CGAffineTransformMakeScale(scaleR * 0.2 + 1, scaleR * 0.2 + 1);    //4.颜色渐变    UIColor *rightColor = [UIColor colorWithRed:scaleR green:0 blue:0 alpha:1];    UIColor *leftColor = [UIColor colorWithRed:scaleL green:0 blue:0 alpha:1];    [rightButton setTitleColor:rightColor forState:UIControlStateNormal];    [leftButton setTitleColor:leftColor forState:UIControlStateNormal];}#pragma mark - 设置所有标题- (void)setupAllTitle {    // 添加所有标题按钮    CGFloat btnX = 0;    CGFloat btnW = 100;    CGFloat btnH = self.titleScrollView.frame.size.height;    for (NSInteger i = 0; i < self.titles.count; i++) {        UIButton *titleButton = [UIButton buttonWithType:UIButtonTypeCustom];        titleButton.tag = i;        btnX = i * btnW;        titleButton.frame = CGRectMake(btnX, 0, btnW, btnH);        [titleButton setTitle:self.titles[i] forState:UIControlStateNormal];        [titleButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];        [titleButton addTarget:self action:@selector(titleButtonClick:) forControlEvents:UIControlEventTouchUpInside];        [self .titleScrollView addSubview:titleButton];        //把按钮保存在titleButtons数组中        [self.titleButtons addObject:titleButton];        if (i == 0) {//默认选中第0个标题            [self titleButtonClick:titleButton];        }    }    self.titleScrollView.contentSize = CGSizeMake(self.titles.count * btnW, 0);    self.contentScrollView.contentSize = CGSizeMake(self.titles.count * ScreenW, 0);}#pragma mark - 选中按钮- (void)selectedButton:(UIButton *)button {    self.previousClickButton.transform = CGAffineTransformIdentity;    [self.previousClickButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];    [button setTitleColor:[UIColor redColor] forState:UIControlStateNormal];    //标题居中    [self setupTitleCenter:button];    //字体缩放    button.transform = CGAffineTransformMakeScale(1.2, 1.2);    self.previousClickButton = button;}#pragma mark - 标题居中- (void)setupTitleCenter:(UIButton *)button {    //修改titleScrollView的偏移量    CGFloat offSetX = button.center.x - ScreenW * 0.5;    if (offSetX < 0) {        offSetX = 0;    }    CGFloat maxOffsetX = self.titleScrollView.contentSize.width - ScreenW;    if (offSetX > maxOffsetX) {        offSetX = maxOffsetX;    }    [self.titleScrollView setContentOffset:CGPointMake(offSetX, 0) animated:YES];}#pragma mark - 加载对应子控制器View- (void)addOneViewController:(NSInteger)i {    UIViewController *childVC = self.childViewControllers[i];    //如果View已经被加载直接返回//    if (childVC.view.superview) return;    if (childVC.viewIfLoaded) return; //ios 9.0之后可以使用    CGFloat childViewW = self.contentScrollView.bounds.size.width;    CGFloat childViewH = self.contentScrollView.bounds.size.height;;    CGFloat childViewX = i * childViewW;    childVC.view.frame = CGRectMake(childViewX, 0, childViewW, childViewH);    [self.contentScrollView addSubview:childVC.view];}#pragma mark - 标题点击- (void)titleButtonClick:(UIButton *)titleButton {    // 1.标题颜色变红    [self selectedButton:titleButton];    // 2.加载对应子控制器View    [self addOneViewController:titleButton.tag];    // 3.内容滚动视图滚动到对应的位置    self.contentScrollView.contentOffset = CGPointMake(titleButton.tag * self.contentScrollView.bounds.size.width, 0);}#pragma mark - 添加所有子控制器- (void)setupAllChildVC {    //注意:控制器加载的顺序要和titles中的一一对应，顺序和数量自己也可以调整    // 头条    [self addChildViewController:[[TopLineViewController alloc] init]];    // 热点    [self addChildViewController:[[HotViewController alloc] init]];    // 视频    [self addChildViewController:[[VideoViewController alloc] init]];    // 社会    [self addChildViewController:[[SocietyViewController alloc] init]];    // 订阅    [self addChildViewController:[[ReadViewController alloc] init]];    // 科技    [self addChildViewController:[[TechViewController alloc] init]];}#pragma mark - 添加标题滚动视图- (void)setupTitleScrollView {    //创建titleScrollView    UIScrollView *titleScrollView = [[UIScrollView alloc] init];    CGFloat y = self.navigationController.navigationBarHidden ? 20 : 64;    titleScrollView.frame = CGRectMake(0, y, ScreenW, 44);    titleScrollView.showsHorizontalScrollIndicator = NO;    [self.view addSubview:titleScrollView];    _titleScrollView = titleScrollView;}#pragma mark - 添加内容滚动视图- (void)setupContentScrollView {    //创建contentScrollView    UIScrollView *contentScrollView = [[UIScrollView alloc] init];    CGFloat y = CGRectGetMaxY(self.titleScrollView.frame);    contentScrollView.frame = CGRectMake(0, y, ScreenW, ScreenH - y);    contentScrollView.pagingEnabled = YES;    contentScrollView.showsHorizontalScrollIndicator = NO;    contentScrollView.bounces = NO;    contentScrollView.delegate = self;    [self.view addSubview:contentScrollView];    _contentScrollView = contentScrollView;}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end