ios - UICollectionView 单元格的水平重新排序
<p><p>我有一个水平滚动的 UICollectionView。每个单元格对应于数组中的一个对象(货币代码)。我想要的是能够通过拖放手势重新排列单元格。</p>
<p>我找到了 <a href="https://www.raywenderlich.com/63089/cookbook-moving-table-view-cells-with-a-long-press-gesture" rel="noreferrer noopener nofollow">tutorial</a>对于 UITableView 并尝试过，但是当我按住并拖动一个单元格时，它只会垂直移动，当我将手指移动到屏幕边缘时不会滚动。这是 <a href="https://i.imgur.com/OzSP0dZ.gifv" rel="noreferrer noopener nofollow">gif</a> .</p>
<p>我想要发生的是让单元格水平移动，而不是垂直移动，并且当到达屏幕边缘时 Collection View 滚动。我将如何实现这一目标？</p>
<p>这就是我现在拥有的:</p>
<pre><code>UILongPressGestureRecognizer *longPress = [ initWithTarget: self action: @selector(longPressGestureRecognised:)];
;
-(IBAction) longPressGestureRecognised:(id)sender
{
UILongPressGestureRecognizer *longPress = (UILongPressGestureRecognizer *)sender;
UIGestureRecognizerState state = longPress.state;
CGPoint location = ;
NSIndexPath *indexPath = ;
static UIView *snapshot = nil;
static NSIndexPath *sourceIndexPath = nil;
switch (state) {
case UIGestureRecognizerStateBegan: {
if (indexPath) {
sourceIndexPath = indexPath;
UICollectionViewCell *cell = ;
// Take a snapshot of the selected item using helper method.
snapshot = ;
// Add the snapshot as subview, centered at cell's centre.
__block CGPoint centre = cell.center;
snapshot.center = centre;
snapshot.alpha = 0.0;
;
[UIView animateWithDuration: 0.25 animations:^{
// Offset for gesture location.
centre.y = location.y;
snapshot.center = centre;
snapshot.transform = CGAffineTransformMakeScale(1.05, 1.05);
snapshot.alpha = 0.98;
// Fade out.
cell.alpha = 0.0;
} completion: ^(BOOL finished) {
cell.hidden = YES;
}];
}
break;
}
case UIGestureRecognizerStateChanged: {
CGPoint centre = snapshot.center;
centre.y = location.y;
snapshot.center = centre;
// Is destination valid and is it different from source?
if (indexPath && !) {
// Update data source.
;
// Move the items.
;
// And update source so it is in sync with UI changes.
sourceIndexPath = indexPath;
}
break;
}
default: {
// Clean up.
UICollectionViewCell *cell = ;
cell.hidden = NO;
cell.alpha = 0.0;
[UIView animateWithDuration: 0.25 animations: ^{
snapshot.center = cell.center;
snapshot.transform = CGAffineTransformIdentity;
snapshot.alpha = 0.0;
// Undo fade out.
cell.alpha = 1.0;
}completion: ^(BOOL finished) {
sourceIndexPath = nil;
;
snapshot = nil;
}];
break;
}
}
}
-(UIView *) customSnapshotFromView:(UIView *)inputView
{
// Make an image from the input view.
UIGraphicsBeginImageContextWithOptions(inputView.bounds.size, NO, 0);
;
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// Create an image view.
UIView *snapshot = [ initWithImage: image];
snapshot.layer.masksToBounds = NO;
snapshot.layer.cornerRadius = 0.0;
snapshot.layer.shadowOffset = CGSizeMake(-5.0, 0.0);
snapshot.layer.shadowRadius = 5.0;
snapshot.layer.shadowOpacity = 0.4;
return snapshot;
}
</code></pre>
<p><strong>编辑:</strong>
我已经想通了。代码如下:</p>
<pre><code>UILongPressGestureRecognizer *longPress = [ initWithTarget: self action: @selector(handleLongGesture:)];
;
-(IBAction) handleLongGesture: (id)sender {
UILongPressGestureRecognizer *longPress = (UILongPressGestureRecognizer *)sender;
CGPoint location = ;
NSIndexPath *indexPath = ;
switch (longPress.state) {
case UIGestureRecognizerStateBegan:
;
NSLog(@"Gesture began");
break;
case UIGestureRecognizerStateChanged:
];
NSLog(@"Gesture state changed");
break;
case UIGestureRecognizerStateEnded:
;
NSLog(@"Gesture state ended");
break;
default:
;
NSLog(@"Gesture cancelled");
break;
}
}
</code></pre></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>在 UIGestureRecognizerStateChanged 中:
修改这行代码</p>
<pre><code> CGPoint centre = snapshot.center;
centre.x = location.x;
snapshot.center = centre;
</code></pre>
<p>center.y 返回 y 轴拖动</p>
<p>将其更改为 center.x 以进行 x 轴拖动</p></p>
<p style="font-size: 20px;">关于ios - UICollectionView 单元格的水平重新排序，我们在Stack Overflow上找到一个类似的问题：
<a href="https://stackoverflow.com/questions/37437614/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/37437614/
</a>
</p>
页:
[1]