iOS使用UICollectionView实现拖拽移动单元格 iOS使用UICollectionView实现拖拽移

一.介绍
二.方法和步骤
三.iOS9之后添加的API

本文实例为大家分享了iOS开发UICollectionView拖拽移动单元格的具体代码，供大家参考，具体内容如下

一.介绍 iOS9提供API实现单元格排序呢功能,使用UICollectionView及其代理方法.iOS9之后有自带方法可以实现该效果,只需添加长按手势,实现手势方法和调用iOS9的API交换数据,iOS9之前需要自己写方法实现这效果,除了要添加长按手势,这里还需要利用截图替换原理,手动计算移动位置来处理视图交换和数据交换.

二.方法和步骤 1.创建工程项目和视图控制器,如下图

文章图片

2.声明对象和设置代理和数据源代理

@interface ViewController () @property (nonatomic, strong) NSMutableArray *dataArr; @property (nonatomic, strong) UICollectionView *collectionView; /**之前选中cell的NSIndexPath*/@property (nonatomic, strong) NSIndexPath *oldIndexPath; /**单元格的截图*/@property (nonatomic, strong) UIView *snapshotView; /**之前选中cell的NSIndexPath*/@property (nonatomic, strong) NSIndexPath *moveIndexPath; @end

3.初始化UICollectionView,并添加长按手势,在viewDidLoad中初始化

CGFloat SCREEN_WIDTH = self.view.frame.size.width; UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init]; flowLayout.itemSize = CGSizeMake((SCREEN_WIDTH-40.0)/3, (SCREEN_WIDTH-40.0)/3); UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 50.0, SCREEN_WIDTH, (SCREEN_WIDTH-40.0)/3+20.0) collectionViewLayout:flowLayout]; collectionView.dataSource = self; collectionView.delegate = self; collectionView.backgroundColor = [UIColor whiteColor]; [collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"uicollectionviewcell"]; [self.view addSubview:self.collectionView = collectionView]; // 添加长按手势UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handlelongGesture:)]; [collectionView addGestureRecognizer:longPress];

4.实例化数据源,(50个随机颜色,透明度0.8),在viewDidLoad中初始化

self.dataArr = [[NSMutableArray alloc] init]; for (NSInteger index = 0; index < 50; index ++) {CGFloat hue = (arc4random()%256/256.0); //0.0 到 1.0CGFloat saturation = (arc4random()%128/256.0)+0.5; //0.5 到 1.0CGFloat brightness = (arc4random()%128/256.0)+0.5; //0.5 到 1.0UIColor *color = [UIColor colorWithHue:hue saturation:saturation brightness:brightness alpha:0.5]; [self.dataArr addObject:color]; }

5.实现UICollectionView的UICollectionViewDataSource的两个必须实现的方法

#pragma mark - UICollectionViewDataSource- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{return self.dataArr.count; } - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"uicollectionviewcell" forIndexPath:indexPath]; cell.backgroundColor = self.dataArr[indexPath.row]; return cell; }

6.重点来了,实现长按手势方法

#pragma mark - 长按手势- (void)handlelongGesture:(UILongPressGestureRecognizer *)longPress{if ([[[UIDevice currentDevice] systemVersion] floatValue] < 9.0) {[self action:longPress]; } else {[self iOS9_Action:longPress]; }}

7.iOS9之后的实现

#pragma mark - iOS9 之后的方法- (BOOL)collectionView:(UICollectionView *)collectionView canMoveItemAtIndexPath:(NSIndexPath *)indexPath{// 返回YES允许row移动return YES; } - (void)collectionView:(UICollectionView *)collectionView moveItemAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath{//取出移动row数据id color = self.dataArr[sourceIndexPath.row]; //从数据源中移除该数据[self.dataArr removeObject:color]; //将数据插入到数据源中的目标位置[self.dataArr insertObject:color atIndex:destinationIndexPath.row]; } - (void)iOS9_Action:(UILongPressGestureRecognizer *)longPress{switch (longPress.state) {case UIGestureRecognizerStateBegan:{ //手势开始//判断手势落点位置是否在row上NSIndexPath *indexPath = [self.collectionView indexPathForItemAtPoint:[longPress locationInView:self.collectionView]]; if (indexPath == nil) {break; }UICollectionViewCell *cell = [self.collectionView cellForItemAtIndexPath:indexPath]; [self.view bringSubviewToFront:cell]; //iOS9方法移动cell[self.collectionView beginInteractiveMovementForItemAtIndexPath:indexPath]; }break; case UIGestureRecognizerStateChanged:{ // 手势改变// iOS9方法移动过程中随时更新cell位置[self.collectionView updateInteractiveMovementTargetPosition:[longPress locationInView:self.collectionView]]; }break; case UIGestureRecognizerStateEnded:{ // 手势结束// iOS9方法移动结束后关闭cell移动[self.collectionView endInteractiveMovement]; }break; default: //手势其他状态[self.collectionView cancelInteractiveMovement]; break; }}

8.iOS9之前的实现

#pragma mark - iOS9 之前的方法- (void)action:(UILongPressGestureRecognizer *)longPress{switch (longPress.state) {case UIGestureRecognizerStateBegan:{ // 手势开始//判断手势落点位置是否在row上NSIndexPath *indexPath = [self.collectionView indexPathForItemAtPoint:[longPress locationInView:self.collectionView]]; self.oldIndexPath = indexPath; if (indexPath == nil) {break; }UICollectionViewCell *cell = [self.collectionView cellForItemAtIndexPath:indexPath]; // 使用系统的截图功能,得到cell的截图视图UIView *snapshotView = [cell snapshotViewAfterScreenUpdates:NO]; snapshotView.frame = cell.frame; [self.view addSubview:self.snapshotView = snapshotView]; // 截图后隐藏当前cellcell.hidden = YES; CGPoint currentPoint = [longPress locationInView:self.collectionView]; [UIView animateWithDuration:0.25 animations:^{snapshotView.transform = CGAffineTransformMakeScale(1.05, 1.05); snapshotView.center = currentPoint; }]; }break; case UIGestureRecognizerStateChanged:{ // 手势改变//当前手指位置截图视图位置随着手指移动而移动CGPoint currentPoint = [longPress locationInView:self.collectionView]; self.snapshotView.center = currentPoint; // 计算截图视图和哪个可见cell相交for (UICollectionViewCell *cell in self.collectionView.visibleCells) {// 当前隐藏的cell就不需要交换了,直接continueif ([self.collectionView indexPathForCell:cell] == self.oldIndexPath) {continue; }// 计算中心距CGFloat space = sqrtf(pow(self.snapshotView.center.x - cell.center.x, 2) + powf(self.snapshotView.center.y - cell.center.y, 2)); // 如果相交一半就移动if (space <= self.snapshotView.bounds.size.width / 2) {self.moveIndexPath = [self.collectionView indexPathForCell:cell]; //移动会调用willMoveToIndexPath方法更新数据源[self.collectionView moveItemAtIndexPath:self.oldIndexPath toIndexPath:self.moveIndexPath]; //设置移动后的起始indexPathself.oldIndexPath = self.moveIndexPath; break; }}}break; default:{ // 手势结束和其他状态UICollectionViewCell *cell = [self.collectionView cellForItemAtIndexPath:self.oldIndexPath]; // 结束动画过程中停止交互,防止出问题self.collectionView.userInteractionEnabled = NO; // 给截图视图一个动画移动到隐藏cell的新位置[UIView animateWithDuration:0.25 animations:^{self.snapshotView.center = cell.center; self.snapshotView.transform = CGAffineTransformMakeScale(1.0, 1.0); } completion:^(BOOL finished) {// 移除截图视图,显示隐藏的cell并开始交互[self.snapshotView removeFromSuperview]; cell.hidden = NO; self.collectionView.userInteractionEnabled = YES; }]; }break; }}

三.iOS9之后添加的API

// Support for reordering- (BOOL)beginInteractiveMovementForItemAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(9_0); // returns NO if reordering was prevented from beginning - otherwise YES- (void)updateInteractiveMovementTargetPosition:(CGPoint)targetPosition NS_AVAILABLE_IOS(9_0); - (void)endInteractiveMovement NS_AVAILABLE_IOS(9_0); - (void)cancelInteractiveMovement NS_AVAILABLE_IOS(9_0);

【iOS使用UICollectionView实现拖拽移动单元格】以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。