@interface ViewController ()<UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout>
@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
2初始化viewDidLoad
CGFloat SCREEN_WIDTH = [UIScreen mainScreen].bounds.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, [UIScreen mainScreen].bounds.size.height) collectionViewLayout:flowLayout];
collectionView.dataSource=self;
collectionView.delegate=self;
collectionView.backgroundColor = [UIColor whiteColor];
[collectionViewregisterClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"uicollectionviewcell"];
[self.viewaddSubview:self.collectionView= collectionView];
// 添加长按手势
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handlelongGesture:)];
[collectionViewaddGestureRecognizer:longPress];
加载数据
self.dataArr = [[NSMutableArray alloc] init];
for (NSIntegerindex =0; index <50; index ++) {
[self.dataArr addObject:[NSString stringWithFormat:@"%ld",index]];
}
#pragma mark - UICollectionViewDataSource
- (NSInteger)collectionView:(UICollectionView*)collectionView numberOfItemsInSection:(NSInteger)section
{
returnself.dataArr.count;
}
- (UICollectionViewCell*)collectionView:(UICollectionView*)collectionView cellForItemAtIndexPath:(NSIndexPath*)indexPath
{
// 每次先从字典中根据IndexPath取出唯一标识符
NSString *identifier = [_cellDic objectForKey:[NSString stringWithFormat:@"%@", indexPath]];
// 如果取出的唯一标示符不存在，则初始化唯一标示符，并将其存入字典中，对应唯一标示符注册Cell
if (identifier ==nil) {
identifier = [NSStringstringWithFormat:@"%@", indexPath];
[_cellDicsetValue:identifierforKey:[NSStringstringWithFormat:@"%@", indexPath]];
// 注册Cell
[self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:identifier];
}
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:identifier forIndexPath:indexPath];
for(idsubViewincell.contentView.subviews){
if(subView){
[subViewremoveFromSuperview];
}
}
CGFloathue = (arc4random()%256/256.0);//0.0 到 1.0
CGFloatsaturation = (arc4random()%128/256.0)+0.5;//0.5 到 1.0
CGFloatbrightness = (arc4random()%128/256.0)+0.5;//0.5 到 1.0
UIColor *color = [UIColor colorWithHue:hue saturation:saturation brightness:brightness alpha:0.5];
cell.backgroundColor= color;
UILabel *lab = [[UILabel alloc]initWithFrame:CGRectMake(10, 10, 100, 20)];
lab.text=self.dataArr[indexPath.row];
[cell.contentView addSubview:lab ];
return cell;
}
#pragma mark - 长按手势
- (void)handlelongGesture:(UILongPressGestureRecognizer*)longPress
{
if ([[[UIDevice currentDevice] systemVersion] floatValue] < 9.0) {
[selfaction:longPress];
} else {
[selfiOS9_Action:longPress];
}
}
#pragma mark - iOS9 之后的方法
- (BOOL)collectionView:(UICollectionView*)collectionView canMoveItemAtIndexPath:(NSIndexPath*)indexPath
{
// 返回YES允许row移动
returnYES;
}
- (void)collectionView:(UICollectionView*)collectionView moveItemAtIndexPath:(NSIndexPath*)sourceIndexPath toIndexPath:(NSIndexPath*)destinationIndexPath
{
//取出移动row数据
iddata =self.dataArr[sourceIndexPath.row];
//从数据源中移除该数据
[self.dataArrremoveObject:data];
//将数据插入到数据源中的目标位置
[self.dataArrinsertObject:dataatIndex:destinationIndexPath.row];
}
- (void)iOS9_Action:(UILongPressGestureRecognizer*)longPress
{
switch (longPress.state) {
caseUIGestureRecognizerStateBegan:
{//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;
caseUIGestureRecognizerStateChanged:
{// 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;
caseUIGestureRecognizerStateEnded:
{// 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;
}
}
#pragma mark - iOS9 之前的方法
- (void)action:(UILongPressGestureRecognizer *)longPress
{
switch (longPress.state) {
caseUIGestureRecognizerStateBegan:
{// 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 = [cellsnapshotViewAfterScreenUpdates:NO];
snapshotView.frame= cell.frame;
[self.viewaddSubview:self.snapshotView= snapshotView];
// 截图后隐藏当前cell
cell.hidden=YES;
CGPointcurrentPoint = [longPresslocationInView:self.collectionView];
[UIView animateWithDuration:0.25 animations:^{
snapshotView.transform=CGAffineTransformMakeScale(1.05,1.05);
snapshotView.center= currentPoint;
}];
}
break;
caseUIGestureRecognizerStateChanged:
{// 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
CGPointcurrentPoint = [longPresslocationInView: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continue
if ([self.collectionViewindexPathForCell:cell] ==self.oldIndexPath) {
continue;
}
// 计算中心距
CGFloatspace =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.collectionViewindexPathForCell: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indexPath
self.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:^(BOOLfinished) {
// 移除截图视图,显示隐藏的cell并开始交互
[self.snapshotViewremoveFromSuperview];
cell.hidden=NO;
self.collectionView.userInteractionEnabled = YES;
}];
}
break;
}
}
