创建UICollectionView----
iOS9 添加的API
- (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);
拖动排序主要使用的是手势
// 添加长按手势
UILongPressGestureRecognizer*longPress = [[UILongPressGestureRecognizeralloc]initWithTarget:selfaction:@selector(handlelongGesture:)];
[collectionViewaddGestureRecognizer:longPress];
#pragma mark - 长按手势
- (void)handlelongGesture:(UILongPressGestureRecognizer*)longPress
{
if([[[UIDevicecurrentDevice]systemVersion]floatValue] <9.0) {
[selfaction:longPress];
}else{
[selfiOS9_Action:longPress];
}
}
#pragma mark - iOS9 之后的方法
- (BOOL)collectionView:(UICollectionView*)collectionViewcanMoveItemAtIndexPath:(NSIndexPath*)indexPath
{
// 返回YES允许row移动
returnYES;
}
- (void)collectionView:(UICollectionView*)collectionViewmoveItemAtIndexPath:(NSIndexPath*)sourceIndexPathtoIndexPath:(NSIndexPath*)destinationIndexPath
{
//取出移动row数据
idcolor =self.dataArr[sourceIndexPath.row];
//从数据源中移除该数据
[self.dataArrremoveObject:color];
//将数据插入到数据源中的目标位置
[self.dataArrinsertObject:coloratIndex: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.collectionViewindexPathForItemAtPoint:[longPresslocationInView:self.collectionView]];
if(indexPath ==nil) {
break;
}
UICollectionViewCell*cell = [self.collectionViewcellForItemAtIndexPath:indexPath];
[self.viewbringSubviewToFront:cell];
//iOS9方法 移动cell
[self.collectionViewbeginInteractiveMovementForItemAtIndexPath:indexPath];
}
break;
caseUIGestureRecognizerStateChanged:
{// 手势改变
// iOS9方法 移动过程中随时更新cell位置
[self.collectionViewupdateInteractiveMovementTargetPosition:[longPresslocationInView:self.collectionView]];
}
break;
caseUIGestureRecognizerStateEnded:
{// 手势结束
// iOS9方法 移动结束后关闭cell移动
[self.collectionViewendInteractiveMovement];
}
break;
default://手势其他状态
[self.collectionViewcancelInteractiveMovement];
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.collectionViewindexPathForItemAtPoint:[longPresslocationInView:self.collectionView]];
self.oldIndexPath= indexPath;
if(indexPath ==nil) {
break;
}
UICollectionViewCell*cell = [self.collectionViewcellForItemAtIndexPath: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;
CGPoint currentPoint = [longPresslocationInView:self.collectionView];
[UIViewanimateWithDuration:0.25animations:^{
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
CGPoint currentPoint = [longPresslocationInView:self.collectionView];
self.snapshotView.center= currentPoint;
// 计算截图视图和哪个可见cell相交
for(UICollectionViewCell*cell inself.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
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.collectionViewindexPathForCell:cell];
//移动 会调用willMoveToIndexPath方法更新数据源
[self.collectionViewmoveItemAtIndexPath:self.oldIndexPathtoIndexPath: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.collectionViewcellForItemAtIndexPath: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
[UIViewanimateWithDuration:0.25animations:^{
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;
}
}
