我有一个 UICollectionView
实现了自定义 UICollectionViewCells
的基于网格的布局。为了让单元格响应拖动,我分别向每个单元格添加了一个 UIPanGestureRecognizer
。
UICollectionView
当我向下触摸并从单元格之间的点开始向左/向右滑动时,UICollectionView
仍然滚动(水平),但只要将平移手势识别器添加到单元格,它似乎CollectionView
在单元格内开始轻扫时拒绝滚动。
现在,我将水平左/右拖动与垂直向上/向下拖动分开,因此拖出单元格(垂直滑动)和滚动 CollectionView
(水平滑动)之间不应该有任何冲突.在这种情况下,我如何将滑动传递给集合/ ScrollView ,以便它知道像正常一样滚动?必须从单元格之间的边界或间距开始,这真的很烦人。
一旦我从单元格中移除平移手势,无论我是在单元格上还是在单元格之间开始滑动,滚动都会正常进行。
编辑:期望的平移手势行为作为当前代码发布在下面
// Handle pans by detecting swipes:
-(void) handlePan:(UIPanGestureRecognizer*)recognizer
{
// Calculate touch location
CGPoint touchXY = [recognizer locationInView:masterWindowView];
// Handle touch
if (recognizer.state == UIGestureRecognizerStateBegan)
{
gestureWasHandled = NO;
pointCount = 1;
startPoint = touchXY;
}
if (recognizer.state == UIGestureRecognizerStateChanged)
{
++pointCount;
// Calculate whether a swipe has occurred
float dX = deltaX(touchXY, startPoint);
float dY = deltaY(touchXY, startPoint);
BOOL finished = YES;
if ((dX > kSwipeDragMin) && (ABS(dY) < kDragLimitMax)) {
touchType = TouchSwipeLeft;
NSLog(@"LEFT swipe detected");
[recognizer requireGestureRecognizerToFail:recognizer];
//[masterScrollView handlePan]
}
else if ((dX < -kSwipeDragMin) && (ABS(dY) < kDragLimitMax)) {
touchType = TouchSwipeRight;
NSLog(@"RIGHT swipe detected");
[recognizer requireGestureRecognizerToFail:recognizer];
}
else if ((dY > kSwipeDragMin) && (ABS(dX) < kDragLimitMax)) {
touchType = TouchSwipeUp;
NSLog(@"UP swipe detected");
}
else if ((dY < -kSwipeDragMin) && (ABS(dX) < kDragLimitMax)) {
touchType = TouchSwipeDown;
NSLog(@"DOWN swipe detected");
}
else
finished = NO;
// If unhandled and downward, produce a new draggable view
if (!gestureWasHandled && finished && (touchType == TouchSwipeDown))
{
[self.delegate cellBeingDragged:self];
dragView.center = touchXY;
dragView.hidden = NO;
dragView.backgroundColor = [UIColor clearColor];
masterScrollView.scrollEnabled = NO; // prevent user from scrolling during
gestureWasHandled = YES;
}
else if (gestureWasHandled)
{
// allow continued dragging after detection
dragView.center = touchXY;
}
}
if (recognizer.state == UIGestureRecognizerStateEnded)
{
// ensure that scroll view returns to scrollable
if (gestureWasHandled) {
[self.delegate cell:self dragEndedAt:touchXY];
}
}
}
// Allow simultaneous recognition
-(BOOL) gestureRecognizer:(UIGestureRecognizer*)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer*)otherGestureRecognizer
{
return YES;
}
此代码在提供给每个单独的单元格时有效。当附加到 UICollectionView 作为其手势识别器时,它不起作用,实际上它会停止所有滚动。
最佳答案
与其将 UIPanGestureRecognizer
附加到每个单元格(这会降低性能),不如将 UIPanGestureRecognizer
添加到 UICollectionView
并在平移手势发生时使用 locationInView
在平移开始的 UICollectionView
中获取点,然后是 indexPathForItemAtPoint
这将返回您应该设置动画的单元格的索引路径。
这样一来,您的整个 Collection View 将只有一个手势识别器(很好!),同时还可以在 View Controller 中保持控制(如您所愿)——双赢!
使用此解决方案,您将在 View Controller 中实现 gestureRecognizer:shouldReceiveTouch: ,捕获给定的 gestureRecognizer,确保它是你的 UIPanGestureRecognizer
并使用它的 translationInView:
方法来确定翻译是在 X 轴还是 Y 轴上。使用该信息来决定是否要返回 YES 或 NO。例如:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
if([gestureRecognizer isEqual:myTapGesture]) {
CGPoint point = [gestureRecognizer translationInView:self.collectionView];
if(point.x != 0) { //adjust this condition if you want some leniency on the X axis
//The translation was on the X axis, i.e. right/left,
//so this gesture recognizer shouldn't do anything about it
return NO;
}
}
return YES;
}
关于ios - 如何将平移手势从 UICollectionViewCell 传递给 UICollectionVIew?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/23776092/