oc版本为啥不用nstimer,而用performSelector
syp1027825441 opened this issue · comments
performSelector会在页面被销毁的时候继续执行导致crash
//
// CWCarousel.m
// CWCarousel
//
// Created by WangChen on 2018/4/3.
// Copyright © 2018年 ChenWang. All rights reserved.
//
#import "CWCarousel.h"
@interface CWTempleteCell: UICollectionViewCell
@EnD
@implementation CWTempleteCell
@EnD
@interface CWCarousel ()<UICollectionViewDelegate, UICollectionViewDataSource> {
}
@Property (nonatomic, strong) UICollectionView carouselView;
@Property (nonatomic, assign) NSInteger numbers;
@Property (nonatomic, assign) NSInteger currentIndex;
@Property (nonatomic, assign) NSInteger infactIndex;
@Property (nonatomic, assign) CGFloat addHeight;
/*
自动播放是否暂停
*/
@Property (nonatomic, assign) BOOL isPause;
/**
当前展示在中间的cell下标
*/
@Property (nonatomic, strong) NSIndexPath *currentIndexPath;
@EnD
@implementation CWCarousel
@synthesize carouselView = _carouselView;
-
(instancetype)initWithFrame:(CGRect)frame delegate:(id)delegate datasource:(id)datasource flowLayout:(CWFlowLayout )flowLayout {
CGFloat addHeight = 0;
// if(flowLayout.style == CWCarouselStyle_H_3) {
// / 如果是CWCarouselStyle_H_3, 因为中间一张图片放大的原因,需要扩充一下frame的高度,所以会和实际的传入的frame
// 的高度有部分偏差
// */
// addHeight = (flowLayout.maxScale - 1) * CGRectGetHeight(frame);
// }
frame.size.height += addHeight;
self.addHeight = addHeight;
if(self = [super initWithFrame:frame]) {
_flowLayout = flowLayout;
self.delegate = delegate;
self.datasource = datasource;
self.isAuto = NO;
self.autoTimInterval = 3;
self.endless = YES;
[self configureView];
}
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appBecomeInactive:) name:UIApplicationWillResignActiveNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appBecomeActive:) name:UIApplicationDidBecomeActiveNotification object:nil];
return self;
} -
(void)appBecomeInactive:(NSNotification *)notification {
[self adjustErrorCell:YES];
} -
(void)appBecomeActive:(NSNotification *)notification {
[self adjustErrorCell:YES];
} -
(void)controllerWillAppear {
if(self.isAuto) {
[self resumePlay];
}
[self adjustErrorCell:YES];
} -
(void)controllerWillDisAppear {
if(self.isAuto) {
[self pause];
}
[self adjustErrorCell:YES];
} -
(void)dealloc {
[self destoryTimer];
[[NSNotificationCenter defaultCenter] removeObserver:self];
} -
(void)willMoveToSuperview:(UIView *)newSuperview {
newSuperview.clipsToBounds = NO;
if(self.customPageControl == nil && self.pageControl.superview == nil) {
[self addSubview:self.pageControl];
self.pageControl.translatesAutoresizingMaskIntoConstraints = NO;
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-0-[control]-0-|"
options:kNilOptions
metrics:nil
views:@{@"control" : self.pageControl}]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[control(30)]-0-|"
options:kNilOptions
metrics:nil
views:@{@"control" : self.pageControl}]];
}else if(self.customPageControl || self.customPageControl.superview == nil) {
[self addSubview:self.customPageControl];
}
[super willMoveToSuperview:newSuperview];
} -
(void)registerViewClass:(Class)viewClass identifier:(NSString *)identifier {
[self.carouselView registerClass:viewClass forCellWithReuseIdentifier:identifier];
} -
(void)registerNibView:(NSString *)nibName identifier:(NSString *)identifier {
[self.carouselView registerNib:[UINib nibWithNibName:nibName bundle:[NSBundle mainBundle]]
forCellWithReuseIdentifier:identifier];
} -
(void)freshCarousel {
if([self numbers] <= 0) {
return;
}
[self.carouselView reloadData];
[self.carouselView layoutIfNeeded];
if (self.endless)
[self.carouselView scrollToItemAtIndexPath:[self originIndexPath] atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:NO];
else
{
if(self.flowLayout.style == CWCarouselStyle_Normal)
{
[self.carouselView scrollToItemAtIndexPath:self.currentIndexPath = [NSIndexPath indexPathForRow:0 inSection:0] atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:NO];
}
else
{
[self.carouselView scrollToItemAtIndexPath:self.currentIndexPath = [NSIndexPath indexPathForRow:1 inSection:0] atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:NO];
}
}self.carouselView.userInteractionEnabled = YES;
if (self.isAuto) {
[self play];
}
}
#pragma mark - < Scroll Delegate >
/// 开始拖拽 -
(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
// 防止拖动加速度太大,一次跳过多张图片,这里设置一下
if (@available(iOS 14.0, *)) {
scrollView.pagingEnabled = NO;
} else {
scrollView.pagingEnabled = YES;
}
if (self.isAuto) {
[self stop];
}
if (self.delegate && [self.delegate respondsToSelector:@selector(CWCarousel:didStartScrollAtIndex:indexPathRow:)]) {
[self.delegate CWCarousel:self didStartScrollAtIndex:[self caculateIndex:self.currentIndexPath.row] indexPathRow:self.currentIndexPath.row];
}
}
/// 将要结束拖拽
-
(void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset {
if (!self.endless)
{
NSInteger maxIndex = [self numbers] - 1;
NSInteger minIndex = 0;
if(self.flowLayout.style != CWCarouselStyle_Normal)
{
maxIndex = [self infactNumbers] - 2;
minIndex = 1;
}
if (velocity.x == 0) {
//还有一种情况,当滑动后手指按住不放,然后松开,此时的加速度其实是为0的
[self adjustErrorCell:NO];
if (@available(iOS 14.0, *)) {
// iOS14以前,就算加速度为0,后续系统会还是会走scrollViewWillBeginDecelerating:回调
// 但是iOS14以后,加速度为0时,不会在后续执行回调.这里手动触发一下
[self scrollViewWillBeginDecelerating:self.carouselView];
}
return;
}
if (velocity.x >= 0 && self.currentIndexPath.row == maxIndex)
{
return;
}
if (velocity.x <= 0 && self.currentIndexPath.row == minIndex)
{
return;
}
}if(velocity.x > 0) {
//左滑,下一张
self.currentIndexPath = [NSIndexPath indexPathForRow:self.currentIndexPath.row + 1 inSection:self.currentIndexPath.section];
}else if (velocity.x < 0) {
//右滑,上一张
self.currentIndexPath = [NSIndexPath indexPathForRow:self.currentIndexPath.row - 1 inSection:self.currentIndexPath.section];
}else if (velocity.x == 0) {
//还有一种情况,当滑动后手指按住不放,然后松开,此时的加速度其实是为0的
[self adjustErrorCell:NO];
if (@available(iOS 14.0, *)) {
// iOS14以前,就算加速度为0,后续系统会还是会走scrollViewWillBeginDecelerating:回调
// 但是iOS14以后,加速度为0时,不会在后续执行回调.这里手动触发一下
[self scrollViewWillBeginDecelerating:self.carouselView];
}
}
}
/// 开始减速
-
(void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView {
if(self.currentIndexPath != nil &&
self.currentIndexPath.row < [self infactNumbers] &&
self.currentIndexPath.row >= 0) {
// 中间一张轮播,居中显示
if (!self.endless)
{
if (self.currentIndexPath.row == 0 && self.style != CWCarouselStyle_Normal)
{
self.currentIndexPath = [NSIndexPath indexPathForRow:1 inSection:self.currentIndexPath.section];
}
else if (self.currentIndexPath.row == [self infactNumbers] - 1 && self.style != CWCarouselStyle_Normal)
{
self.currentIndexPath = [NSIndexPath indexPathForRow:[self infactNumbers] - 2 inSection:self.currentIndexPath.section];
}
}
[self.carouselView scrollToItemAtIndexPath:self.currentIndexPath atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
}
}
/// 减速完成
-
(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
// 打开交互
scrollView.pagingEnabled = NO;
if(self.isAuto) {
[self play];
}
}
/// 滚动动画完成
-
(void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView {
// 滚动完成,打开交互,关掉pagingEnabled
// 为什么要关掉pagingEnabled呢,因为切换控制器的时候会有系统级bug,不信你试试.
scrollView.userInteractionEnabled = YES;
scrollView.pagingEnabled = NO;
if(self.isAuto) {
[self play];
}
if (self.endless)
[self checkOutofBounds];
// if(!self.endless)
// {
// CGFloat space = self.flowLayout.itemSpace_H + self.flowLayout.itemWidth * (1 - self.flowLayout.minScale) * 0.5;
// if(self.currentIndexPath.row == 0)
// self.carouselView.contentInset = UIEdgeInsetsMake(0, space, 0, 0);
// else if(self.currentIndexPath.row == [self numbers] - 1)
// self.carouselView.contentInset = UIEdgeInsetsMake(0, 0, 0, space);
// else
// self.carouselView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0);
// }
if (self.delegate && [self.delegate respondsToSelector:@selector(CWCarousel:didEndScrollAtIndex:indexPathRow:)]) {
[self.delegate CWCarousel:self didEndScrollAtIndex:[self caculateIndex:self.currentIndexPath.row] indexPathRow:self.currentIndexPath.row];
}
}
// 滚动中
-
(void)scrollViewDidScroll:(UIScrollView *)scrollView {
// 滚动过程中关闭交互
// scrollView.userInteractionEnabled = NO;
}
#pragma mark - < Logic Helper > -
(NSIndexPath *)originIndexPath {
NSInteger num = [self numbers];
if (num <= 0) {
return [[NSIndexPath alloc] initWithIndex:0];
}NSInteger centerIndex = [self infactNumbers] / [self numbers];
if (self.endless) {
if(centerIndex <= 1) {
if (centerIndex == 1) {
self.currentIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
}else {
self.currentIndexPath = [NSIndexPath indexPathForRow:self.numbers inSection:0];
}
}else {
self.currentIndexPath = [NSIndexPath indexPathForRow:centerIndex / 2 * [self numbers] inSection:0];
}
}else {
NSInteger row = self.flowLayout.style == CWCarouselStyle_Normal ? 0 : 1;
self.currentIndexPath = [NSIndexPath indexPathForRow:row inSection:0];
}return self.currentIndexPath;
} -
(void)checkOutofBounds {
if ([self numbers] <= 0) {return;}
// 越界检查
if(self.currentIndexPath.row == [self infactNumbers] - 1) {
//最后一张
NSIndexPath *origin = [self originIndexPath];
NSInteger index = [self caculateIndex:self.currentIndexPath.row] - 1;
self.currentIndexPath = [NSIndexPath indexPathForRow:origin.row + index inSection:origin.section];
[self.carouselView scrollToItemAtIndexPath:self.currentIndexPath atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:NO];
self.carouselView.userInteractionEnabled = YES;
}else if(self.currentIndexPath.row == 0) {
//第一张
NSIndexPath *origin = [self originIndexPath];
NSInteger index = [self caculateIndex:self.currentIndexPath.row];
self.currentIndexPath = [NSIndexPath indexPathForRow:origin.row + index inSection:origin.section];
[self.carouselView scrollToItemAtIndexPath:self.currentIndexPath atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:NO];
self.carouselView.userInteractionEnabled = YES;
}
} -
(void)pageControlClick:(UIPageControl *)sender {
if (![sender isKindOfClass:[UIPageControl class]]) {
return;
}
NSInteger page = sender.currentPage;
NSInteger prePage = [self caculateIndex:self.currentIndexPath.row];
if(page == prePage) {
return;
}
NSIndexPath *indexPath = nil;
if(prePage - page == [self numbers] - 1) {
//最后一张跳到第一张
indexPath = [NSIndexPath indexPathForRow:self.currentIndexPath.row + 1 inSection:0];
}else if(page - prePage == [self numbers] - 1) {
//第一张跳到最后一张
indexPath = [NSIndexPath indexPathForRow:self.currentIndexPath.row - 1 inSection:0];
}else {
indexPath = [NSIndexPath indexPathForRow:self.currentIndexPath.row + page - prePage inSection:0];
}
[self.carouselView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
self.currentIndexPath = indexPath;
}
/**
实际下标转换成业务需求下标
@param factIndex 实际下标
@return 业务需求下标
*/
-
(NSInteger)caculateIndex:(NSInteger)factIndex {
if (self.numbers <= 0) {
return 0;
}
NSInteger row = factIndex % [self numbers];
if(!self.endless && self.flowLayout.style != CWCarouselStyle_Normal)
{
row = factIndex % [self infactNumbers] - 1;
}
return row;
} -
(void)adjustErrorCell:(BOOL)isScroll {
NSArray <NSIndexPath *> *indexPaths = [self.carouselView indexPathsForVisibleItems];
NSMutableArray <UICollectionViewLayoutAttributes *> *attriArr = [NSMutableArray arrayWithCapacity:indexPaths.count];
[indexPaths enumerateObjectsUsingBlock:^(NSIndexPath * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
UICollectionViewLayoutAttributes *attri = [self.carouselView layoutAttributesForItemAtIndexPath:obj];
[attriArr addObject:attri];
}];
CGFloat centerX = self.carouselView.contentOffset.x + CGRectGetWidth(self.carouselView.frame) * 0.5;
__block CGFloat minSpace = MAXFLOAT;
// BOOL shouldSet = YES;
// if (self.flowLayout.style != CWCarouselStyle_Normal && indexPaths.count <= 2)
// {
// shouldSet = NO;
// }
[attriArr enumerateObjectsUsingBlock:^(UICollectionViewLayoutAttributes * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
obj.zIndex = 0;
// if(ABS(minSpace) > ABS(obj.center.x - centerX) && shouldSet) {
// minSpace = obj.center.x - centerX;
// self.currentIndexPath = obj.indexPath;
// }
if(ABS(minSpace) > ABS(obj.center.x - centerX)) {
minSpace = obj.center.x - centerX;
self.currentIndexPath = obj.indexPath;
}
}];
if(isScroll) {
[self scrollViewWillBeginDecelerating:self.carouselView];
}
} -
(void)play {
[self stop];
if(self.isPause) {
return;
}
[self showTimer];
// [self performSelector:@selector(nextCell) withObject:nil afterDelay:self.autoTimInterval];
} -
(void)showTimer
{
if (!_timer) {
//开始倒计时
WS(weakSelf)
_timer = [NSTimer bk_scheduledTimerWithTimeInterval:self.autoTimInterval block:^(NSTimer *timer) {
[weakSelf nextCell];
} repeats:YES];
// [_timer setFireDate:[NSDate date]];
//不受滚动事件影响
[[NSRunLoop mainRunLoop] addTimer:_timer forMode:NSRunLoopCommonModes];
} else {
[_timer setFireDate:[NSDate dateWithTimeInterval:self.autoTimInterval sinceDate:[NSDate date]]];
}
}
-(void)destoryTimer
{
if (_timer) {
[_timer invalidate];
_timer = nil;
}
}
-
(void)nextCell {
if([self numbers] <= 0) {
return;
}
NSInteger maxIndex = 1;
if(!self.endless && self.flowLayout.style != CWCarouselStyle_Normal)
{
maxIndex = 2;
}
if(self.currentIndexPath.row < [self infactNumbers] - maxIndex)
{
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:self.currentIndexPath.row + 1 inSection:self.currentIndexPath.section];
[self.carouselView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
self.currentIndexPath = indexPath;
}
else if(!self.endless)
{
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:maxIndex - 1 inSection:self.currentIndexPath.section];
[self.carouselView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
self.currentIndexPath = indexPath;
}
// [self performSelector:@selector(nextCell) withObject:nil afterDelay:self.autoTimInterval];
} -
(void)stop {
if (_timer) {
[_timer setFireDate:[NSDate distantFuture]];
}
// [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(nextCell) object:nil];
// [NSObject cancelPreviousPerformRequestsWithTarget:self];
} -
(void)resumePlay {
self.isPause = NO;
[self play];
} -
(void)pause {
self.isPause = YES;
[self stop];
} -
(void)releaseTimer {
[self stop];
}
#pragma mark - < Configure View>
- (void)configureView {
self.backgroundColor = [UIColor blackColor];
self.carouselView.showsVerticalScrollIndicator = NO;
self.carouselView.showsHorizontalScrollIndicator = NO;
self.carouselView.decelerationRate = 0;
}
#pragma mark - < Delegate, Datasource >
-
(nonnull __kindof UICollectionViewCell *)collectionView:(nonnull UICollectionView *)collectionView cellForItemAtIndexPath:(nonnull NSIndexPath *)indexPath {
if(!self.endless
&& self.flowLayout.style != CWCarouselStyle_Normal
&& (indexPath.row == 0 || indexPath.row == [self infactNumbers] - 1))
{
// 添加占位cell
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"tempCell" forIndexPath:indexPath];
cell.contentView.backgroundColor = [UIColor clearColor];
return cell;
}
else
{
if(self.datasource &&
[self.datasource respondsToSelector:@selector(viewForCarousel:indexPath:index:)])
{
UICollectionViewCell *cell = [self.datasource viewForCarousel:self indexPath:indexPath index:[self caculateIndex:indexPath.row]];
return cell;
}
return nil;
}
} -
(NSInteger)collectionView:(nonnull UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
if([self numbers] > 0)
return [self infactNumbers];
else
return 0;
} -
(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
if(self.delegate &&
[self.delegate respondsToSelector:@selector(CWCarousel:didSelectedAtIndex:)]) {
[self.delegate CWCarousel:self didSelectedAtIndex:[self caculateIndex:indexPath.row]];
}
// 处于动画中时,点击cell,可能会出现cell不居中问题.这里处理下
// 将里中心点最近的那个cell居中
[self adjustErrorCell:YES];
}
#pragma mark -
-
(void)setBackgroundColor:(UIColor *)backgroundColor {
self.carouselView.backgroundColor = backgroundColor;
[super setBackgroundColor:backgroundColor];
} -
(void)setCurrentIndexPath:(NSIndexPath *)currentIndexPath {
_currentIndexPath = currentIndexPath;
if(self.customPageControl == nil)
self.pageControl.currentPage = [self caculateIndex:currentIndexPath.row];
else
self.customPageControl.currentPage = [self caculateIndex:currentIndexPath.row];
} -
(void)setEndless:(BOOL)endless {
if(_endless != endless)
{
_endless = endless;
}
}
#pragma mark - < getter >
-
(UICollectionView *)carouselView {
if(!_carouselView) {
// self.carouselView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, self.addHeight * 0.5, self.frame.size.width, self.frame.size.height - self.addHeight) collectionViewLayout:self.flowLayout];
self.carouselView = [[UICollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:self.flowLayout];
_carouselView.clipsToBounds = NO;
_carouselView.delegate = self;
_carouselView.dataSource = self;
_carouselView.translatesAutoresizingMaskIntoConstraints = NO;
[_carouselView registerClass:[CWTempleteCell class] forCellWithReuseIdentifier:@"tempCell"];
[self addSubview:_carouselView];NSDictionary *views = @{@"view" : self.carouselView}; NSDictionary *margins = @{@"top" : @(self.addHeight * 0.5), @"bottom" : @(self.addHeight * 0.5) }; NSString *str = @"H:|-0-[view]-0-|"; [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:str options:kNilOptions metrics:margins views:views]]; str = @"V:|-top-[view]-top-|"; [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:str options:kNilOptions metrics:margins views:views]];
}
return _carouselView;
} -
(CWCarouselStyle)style {
if(self.flowLayout)
{
return self.flowLayout.style;
}
return CWCarouselStyle_Unknow;
}
/**
Description
@return 业务需求需要展示轮播图个数
*/
- (NSInteger)numbers {
if(self.datasource &&
[self.datasource respondsToSelector:@selector(numbersForCarousel)]) {
self.pageControl.numberOfPages = [self.datasource numbersForCarousel];
return self.pageControl.numberOfPages;
}
return 0;
}
/**
轮播图实际加载视图个数
@return 轮播图实际加载视图个数
*/
-
(NSInteger)infactNumbers {
NSInteger num = [self numbers];
if ( 0 >= num) {
return 0;
}[self.carouselView setScrollEnabled:YES];
if (self.endless)
{
if (num < 1) {
[self.carouselView setScrollEnabled:NO];
return num;
}
// 如果是无限轮播,默认加载300个
return 300;
}
else
{
// 如果不是无限轮播,出了第一种样式,其他的样式要加2个占位空cell
if(self.flowLayout.style == CWCarouselStyle_Normal)
{
return [self numbers];
}
else
{
if (num == 1) {
[self.carouselView setScrollEnabled:NO];
}
// 前后2个占位cell,所以+2
return [self numbers] + 2;
}
}
} -
(UIPageControl *)pageControl {
if(!_pageControl) {
self.pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(0, 0, 300, 30)];
CGPoint center = self.center;
center.y = CGRectGetHeight(self.frame) - 30 * 0.5;
_pageControl.pageIndicatorTintColor = [UIColor blackColor];
_pageControl.currentPageIndicatorTintColor = [UIColor whiteColor];
_pageControl.userInteractionEnabled = NO;
[_pageControl addTarget:self action:@selector(pageControlClick:) forControlEvents:UIControlEventTouchUpInside];
_pageControl.center = center;
}
return _pageControl;
} -
(NSString *)version {
return @"1.1.7";
}
#pragma mark - Setter
- (void)setCustomPageControl:(UIView *)customPageControl {
_customPageControl = customPageControl;
if(_customPageControl && _customPageControl.superview == nil)
{
[self addSubview:_customPageControl];
[self bringSubviewToFront:_customPageControl];
if(self.pageControl.superview == _customPageControl.superview)
{
[self.pageControl removeFromSuperview];
}
}
}
@EnD
@Property (nonatomic, weak) NSTimer *timer;这段代码加到.h文件
NSTimer用的是#import "NSTimer+BlocksKit.h",和控制器解耦,避免内存泄漏
不管是使用timer还是perform,都是要在对应的地方编写移除代码的。个人认为其实是没有太大差别的(当然timer功能上会更强大一些)。控件有对应的销毁方法暴露在.h文件中,你应该是没有调用而导致的。