最近工程里面需要添加一个UICollectionViewCell的移动和删除的效果，查看了很多网上的资料发现，很多人写的cell移动的效果其实不是移动的效果，只是个交换的效果 。还有删除的效果发现这方面的资料太少了，所以自己写了这篇文章。欢迎批评，吐槽！！！
一.效果图
2016-07-22_13-22-28.gif
二.不啰嗦，上代码
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
self.array = [NSMutableArray arrayWithObjects:@"1", @"2", @"3", @"4",
@"5", @"6", @"7", @"8",
@"9", @"10", @"11", @"12",@"13", @"14", @"15", @"16",
@"17", @"18", @"19", @"20", nil];
//长按手势添加到self.collectionView上面
_longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(lonePressMoving:)];
[self.collectionView addGestureRecognizer:_longPress];
[self.view addSubview:self.collectionView];
}
懒加载和布局collectionview的代码
//懒加载
- (NSMutableArray *)array{
if (!_array) {
_array = [NSMutableArray array];
}
return _array;
}
//UICollectionViewCell布局代码
- (UICollectionView *)collectionView
{
if (!_collectionView) {
_flowLayout = [[UICollectionViewFlowLayout alloc] init];
_flowLayout.minimumLineSpacing = 10;
_flowLayout.minimumInteritemSpacing = 10;
_flowLayout.sectionInset = UIEdgeInsetsMake(0, 5, 0, 5);//分区内边距
CGFloat totalWidth = kWidth-40;
CGFloat itemWidth = (totalWidth)/3.0;
CGFloat itemHeght = 33;
//注意：item的宽高必须要提前算好
_flowLayout.itemSize = CGSizeMake(itemWidth, itemHeght);
//创建collectionView对象，并赋值布局
_collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 40, kWidth, kHeight - 20) collectionViewLayout:_flowLayout];
_collectionView.dataSource = self;
_collectionView.backgroundColor = [UIColor whiteColor];
_collectionView.delegate = self;
[_collectionView registerClass:[CollectionViewCell class] forCellWithReuseIdentifier:@"cellIdentiifer"];
}
return _collectionView;
}
长按手势事件判断－>核心代码
- (void)lonePressMoving: (UILongPressGestureRecognizer *)longPress
{
switch (_longPress.state) {
case UIGestureRecognizerStateBegan: {
{
NSIndexPath *selectIndexPath = [self.collectionView indexPathForItemAtPoint:[_longPress locationInView:self.collectionView]];
// 找到当前的cell
CollectionViewCell *cell = (CollectionViewCell *)[self.collectionView cellForItemAtIndexPath:selectIndexPath];
// 定义cell的时候btn是隐藏的, 在这里设置为NO
[cell.btnDelete setHidden:NO];
cell.btnDelete.tag = selectIndexPath.item;
//添加删除的点击事件
[cell.btnDelete addTarget:self action:@selector(btnDelete:) forControlEvents:UIControlEventTouchUpInside];
[_collectionView beginInteractiveMovementForItemAtIndexPath:selectIndexPath];
}
break;
}
case UIGestureRecognizerStateChanged: {
[self.collectionView updateInteractiveMovementTargetPosition:[longPress locationInView:_longPress.view]];
break;
}
case UIGestureRecognizerStateEnded: {
[self.collectionView endInteractiveMovement];
break;
}
default: [self.collectionView cancelInteractiveMovement];
break;
}
}
UICollectionViewCell的代理事件
#pragma mark---UICollectionViewDataSource
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
return self.array.count;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cellIdentiifer" forIndexPath:indexPath];
cell.lable.text = self.array[indexPath.item];
cell.btnDelete.hidden = YES;
return cell;
}
#pragma mark---UICollectionViewDelegate
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
NSLog(@"%@",self.array[indexPath.item]);
}
//添加代码
- (void)collectionView:(UICollectionView *)collectionView moveItemAtIndexPath:(nonnull NSIndexPath *)sourceIndexPath toIndexPath:(nonnull NSIndexPath *)destinationIndexPath
{
NSIndexPath *selectIndexPath = [self.collectionView indexPathForItemAtPoint:[_longPress locationInView:self.collectionView]];
// 找到当前的cell
CollectionViewCell *cell = (CollectionViewCell *)[self.collectionView cellForItemAtIndexPath:selectIndexPath];
cell.btnDelete.hidden = YES;
/*1.存在的问题,移动是二个一个移动的效果*/
// [collectionView moveItemAtIndexPath:sourceIndexPath toIndexPath:destinationIndexPath];
/*2.存在的问题：只是交换而不是移动的效果*/
// [self.array exchangeObjectAtIndex:sourceIndexPath.item withObjectAtIndex:destinationIndexPath.item];
/*3.完整的解决效果*/
//取出源item数据
id objc = [self.array objectAtIndex:sourceIndexPath.item];
//从资源数组中移除该数据
[self.array removeObject:objc];
//将数据插入到资源数组中的目标位置上
[self.array insertObject:objc atIndex:destinationIndexPath.item];
[self.collectionView reloadData];
}
//删除代码
#pragma mark---btn的删除cell事件
- (void)btnDelete:(UIButton *)btn{
//cell的隐藏删除设置
NSIndexPath *selectIndexPath = [self.collectionView indexPathForItemAtPoint:[_longPress locationInView:self.collectionView]];
// 找到当前的cell
CollectionViewCell *cell = (CollectionViewCell *)[self.collectionView cellForItemAtIndexPath:selectIndexPath];
cell.btnDelete.hidden = NO;
//取出源item数据
id objc = [self.array objectAtIndex:btn.tag];
//从资源数组中移除该数据
[self.array removeObject:objc];
[self.collectionView reloadData];
}
三. 实现功能－－－注意事项
3.1移动cell的主要注意点
/*1.存在的问题,移动是二个一个移动的效果*/
// [collectionView moveItemAtIndexPath:sourceIndexPath toIndexPath:destinationIndexPath];
/*2.存在的问题：只是交换而不是移动的效果*/
// [self.array exchangeObjectAtIndex:sourceIndexPath.item withObjectAtIndex:destinationIndexPath.item];
/*3.完整的解决效果*/
//取出源item数据
id objc = [self.array objectAtIndex:sourceIndexPath.item];
//从资源数组中移除该数据
[self.array removeObject:objc];
//将数据插入到资源数组中的目标位置上
[self.array insertObject:objc atIndex:destinationIndexPath.item];
[self.collectionView reloadData];
3.2遇到一个问题：长安手势不是很灵敏
发现的问题是：自己将长安的手势添加到了具体的每个cell上面了.
解决的方法：将长按手势添加到self.collectionView上即可.
