效果图
思路
整体上我们使用tableView实现，为了预留内容的缓冲，我们将tableView 的contentinset设置为上面一个屏幕的高度，下面一个屏幕的高度，左右为0，这样保证我们滚动过去的时候
都是准备好的内容
然后就是滑动效果的实现了,主要就是我们在scrollViewWillEndDragging方法中获取到停止拖动（手指离开）时候的速度。 在scrollViewDidEndDragging 方法中
通过translationInView方法判断当前滑动的方向，
然后刚才获取到的速度就派上用场了，当我们手指离开时候的速度大于0.4的时候，我们切换页面的临界偏移量就是8 ，否则临界偏移量就是60， 同时，通过
CGPoint translatedPoint = [scrollView.panGestureRecognizer translationInView:scrollView];判断translatedPoint.y我们可以
判断滚动的方向，判断出方向之后，
使用UIView animateWithDuration动画快速翻页
代码
//
// ViewController.m
// LBDouyinScroll
//
// Created by mac on 2024/6/26.
//
#import "ViewController.h"
#import "DouyinScrollTableViewCell.h"
#define kScreenWidth [UIScreen mainScreen].bounds.size.width
#define kScreenHeight [UIScreen mainScreen].bounds.size.height
@interface ViewController ()
@property (nonatomic, strong) UITableView *tableView;
@property (nonatomic, assign) NSInteger currentIndex;
@property (nonatomic, assign) CGFloat velocity;
@property (nonatomic, strong) NSMutableArray *colorArray;
@end
@implementation ViewController
- (BOOL)prefersStatusBarHidden
{
return YES;
}
- (void)viewDidLoad {
[super viewDidLoad];
[self.view addSubview:self.tableView];
self.colorArray = [NSMutableArray array];
for (int i = 0; i < 10; i ++) {
int r = arc4random() % 255;
int g = arc4random() % 255;
int b = arc4random() % 255;
CGFloat rr = r / 255.0;
CGFloat rg = g / 255.0;
CGFloat rb = b / 255.0;
UIColor *color = [[UIColor alloc]initWithRed:rr green:rg blue:rb alpha:1];
[self.colorArray addObject:color];
}
[self.tableView reloadData];
// Do any additional setup after loading the view.
}
#pragma mark - UITableViewDelegate, UITableViewDataSource
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
DouyinScrollTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:NSStringFromClass([DouyinScrollTableViewCell class])];
[cell updateWithColor:self.colorArray[indexPath.row]];
// cell.textLabel.text = [NSString stringWithFormat:@"%ld",indexPath.row];
// cell.backgroundColor = self.colorArray[indexPath.row];
// if (!cell.contentView.backgroundColor) {
// cell.contentView.backgroundColor = self.colorArray[indexPath.row];
// }
// return cell;
return cell;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 10;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return kScreenHeight;
}
#pragma mark - scrolllVIewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
}
- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset
{
self.velocity = velocity.y;
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
dispatch_async(dispatch_get_main_queue(), ^{
CGPoint translatedPoint = [scrollView.panGestureRecognizer translationInView:scrollView];
//UITableView禁止响应其他滑动手势
scrollView.panGestureRecognizer.enabled = NO;
CGFloat translateCheck = 60;
if (fabs(self.velocity) > 0.4) {
translateCheck = 8;
}
if(translatedPoint.y < -translateCheck && self.currentIndex < 10) {
self.currentIndex ++; //向下滑动索引递增
}
if(translatedPoint.y > translateCheck && self.currentIndex > 0) {
self.currentIndex --; //向上滑动索引递减
}
if (self.currentIndex == 10) {
} else {
[UIView animateWithDuration:0.15
delay:0.0
options:UIViewAnimationOptionCurveEaseOut animations:^{
//UITableView滑动到指定cell
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:self.currentIndex inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:NO];
} completion:^(BOOL finished) {
//UITableView可以响应其他滑动手势
scrollView.panGestureRecognizer.enabled = YES;
}];
}
});
}
#pragma - private
- (void)animationToIndex:(NSInteger)index
{
[UIView animateWithDuration:0.2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
self.tableView.contentOffset = CGPointMake(0, kScreenHeight * index);
} completion:^(BOOL finished) {
}];
}
#pragma mark - lazy load
- (UITableView *)tableView
{
if (!_tableView) {
_tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, - kScreenHeight, CGRectGetWidth(self.view.bounds), kScreenHeight * 3) style:UITableViewStylePlain];
[_tableView registerClass:[DouyinScrollTableViewCell class] forCellReuseIdentifier:NSStringFromClass([DouyinScrollTableViewCell class])];
_tableView.rowHeight = kScreenHeight;
_tableView.contentInset = UIEdgeInsetsMake(kScreenHeight , 0, kScreenHeight, 0);
_tableView.estimatedRowHeight = kScreenHeight;
_tableView.delegate = self;
_tableView.dataSource = self;
_tableView.backgroundColor = [UIColor redColor];
_tableView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
_tableView.separatorInset = UIEdgeInsetsZero;
_tableView.decelerationRate = UIScrollViewDecelerationRateFast;
}
return _tableView;
}
@end
其中最关键的就是下面的
- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset
{
self.velocity = velocity.y;
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
dispatch_async(dispatch_get_main_queue(), ^{
CGPoint translatedPoint = [scrollView.panGestureRecognizer translationInView:scrollView];
//UITableView禁止响应其他滑动手势
scrollView.panGestureRecognizer.enabled = NO;
CGFloat translateCheck = 60;
if (fabs(self.velocity) > 0.4) {
translateCheck = 8;
}
if(translatedPoint.y < -translateCheck && self.currentIndex < 10) {
self.currentIndex ++; //向下滑动索引递增
}
if(translatedPoint.y > translateCheck && self.currentIndex > 0) {
self.currentIndex --; //向上滑动索引递减
}
if (self.currentIndex == 10) {
} else {
[UIView animateWithDuration:0.15
delay:0.0
options:UIViewAnimationOptionCurveEaseOut animations:^{
//UITableView滑动到指定cell
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:self.currentIndex inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:NO];
} completion:^(BOOL finished) {
//UITableView可以响应其他滑动手势
scrollView.panGestureRecognizer.enabled = YES;
}];
}
});
}
demo: link
