Uitableview 如何为iPad创建类似safari工具栏定制的拖放功能
我有一个UIViewController,上面有一个UITable和一个UIView。我希望能够拾取显示在UIView中的项目并将其放到UITableView中的单元格中。我必须恢复使用触摸事件而不是新的UIGestureRecognitors来拍摄点击的UIView的快照,以便将此快照拖到UITableView而不是UIView。使用以下命令,这非常有效:Uitableview 如何为iPad创建类似safari工具栏定制的拖放功能,uitableview,ios5,drag-and-drop,Uitableview,Ios5,Drag And Drop,我有一个UIViewController,上面有一个UITable和一个UIView。我希望能够拾取显示在UIView中的项目并将其放到UITableView中的单元格中。我必须恢复使用触摸事件而不是新的UIGestureRecognitors来拍摄点击的UIView的快照,以便将此快照拖到UITableView而不是UIView。使用以下命令,这非常有效: -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *t =[touches anyObject];
UIGraphicsBeginImageContext(t.view.bounds.size);
[t.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
self.draggedView = [[UIImageView alloc] initWithImage:img];
CGPoint centre = [[touches anyObject] locationInView:self.view];
[self.draggedView setCenter:centre];
[self.draggedView setAlpha:0.5];
[self.view addSubview:self.draggedView];
}
但是,在touchesEnded事件中,当我尝试评估触摸在哪个UIView上结束时,我总是得到一个UIView,而不是我在UITableView上放置时得到的UIView。任何想法都是非常受欢迎的。因此,我提出的解决方案允许我将视图拖放到表视图单元格上,设置单元格图像属性以匹配正在拖动的UIView,如下所示 首先,我必须实现touchMoved来移动alpha混合视图,因为它被拖到要放置它的单元格上
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
CGPoint centre = [[touches anyObject] locationInView:self.view];
[self.draggedView setCenter:centre];
}
然后在touchSended上,我对tableview进行了命中测试,返回UITableViewCellContentView(UIView*hit)。通过询问hit view的superview,您可以获得单元格hit,从而可以设置其图像
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
CGPoint centre = [[touches anyObject] locationInView:self.view];
UIView *hit = [self.tableView hitTest:centre withEvent:event];
UIGraphicsBeginImageContext(self.draggedView.bounds.size);
[self.draggedView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
if(hit!=nil){
UITableViewCell *tvc = (UITableViewCell *)hit.superview;
[tvc.imageView setImage:img];
}
[self.draggedView removeFromSuperview];
self.draggedView = nil;
}
希望这对某人有所帮助。我想我已经用最新的手势识别器找到了更好的解决方案。我在基本TableView控制器中使用以下LongPress手势识别器
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
if([gestureRecognizer isKindOfClass:[UILongPressGestureRecognizer class]]){
[gestureRecognizer addTarget:self action:@selector(longGestureAction:)];
}
return YES;
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
return YES;
}
-(void)longGestureAction:(UILongPressGestureRecognizer *)gesture{
UITableViewCell *cell= (UITableViewCell *)[gesture view];
switch ([gesture state]) {
case UIGestureRecognizerStateBegan:{
NSIndexPath *ip = [self.tableView indexPathForCell:cell];
[self.tableView setScrollEnabled:NO];
if(ip!=nil){
[self.draggableDelegate dragAndDropTableViewController:self draggingGestureWillBegin:gesture forCell:cell];
UIView *draggedView = [self.draggableDelegate dragAndDropTableViewControllerView:self ];
//switch the view the gesture is associated with this will allow the dragged view to continue on where the cell leaves off from
[draggedView addGestureRecognizer:[[cell gestureRecognizers]objectAtIndex:0]];
[self.draggableDelegate dragAndDropTableViewController:self draggingGestureDidBegin:gesture forCell:cell];
}
}
break;
case UIGestureRecognizerStateChanged:{
[self.draggableDelegate dragAndDropTableViewController:self draggingGestureDidMove:gesture];
}
break;
case UIGestureRecognizerStateEnded:{
UIView *draggedView = [self.draggableDelegate dragAndDropTableViewControllerView:self];
if(draggedView==nil)
return;
//this does not seem like the best way to do this yet you really don't want to fire one after the other I don't think
[self.draggableDelegate dragAndDropTableViewController:self draggingGestureDidEnd:gesture];
[self.dropableDelegate dragAndDropTableViewController:self droppedGesture:gesture];
[self.tableView setScrollEnabled:YES];
[self.tableView reloadData];
}
break;
// case UIGestureRecognizerStateCancelled:
// case UIGestureRecognizerStateFailed:
// case UIGestureRecognizerStatePossible:
// [self.dragAndDropDelegate dragAndDropTableViewController:self draggingGesture:gesture endedForItem:nil];
break;
default:
break;
}
}
在扩展该基类的TableView中,我向cellForIndexPath TableViewDataSource中的每个单元格添加了以下内容:
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:cell action:nil];
longPress.delegate = self;
[cell addGestureRecognizer:longPress];
最后,您需要做的就是实现委托方法
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
if([gestureRecognizer isKindOfClass:[UILongPressGestureRecognizer class]]){
[gestureRecognizer addTarget:self action:@selector(longGestureAction:)];
}
return YES;
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
return YES;
}
-(void)longGestureAction:(UILongPressGestureRecognizer *)gesture{
UITableViewCell *cell= (UITableViewCell *)[gesture view];
switch ([gesture state]) {
case UIGestureRecognizerStateBegan:{
NSIndexPath *ip = [self.tableView indexPathForCell:cell];
[self.tableView setScrollEnabled:NO];
if(ip!=nil){
[self.draggableDelegate dragAndDropTableViewController:self draggingGestureWillBegin:gesture forCell:cell];
UIView *draggedView = [self.draggableDelegate dragAndDropTableViewControllerView:self ];
//switch the view the gesture is associated with this will allow the dragged view to continue on where the cell leaves off from
[draggedView addGestureRecognizer:[[cell gestureRecognizers]objectAtIndex:0]];
[self.draggableDelegate dragAndDropTableViewController:self draggingGestureDidBegin:gesture forCell:cell];
}
}
break;
case UIGestureRecognizerStateChanged:{
[self.draggableDelegate dragAndDropTableViewController:self draggingGestureDidMove:gesture];
}
break;
case UIGestureRecognizerStateEnded:{
UIView *draggedView = [self.draggableDelegate dragAndDropTableViewControllerView:self];
if(draggedView==nil)
return;
//this does not seem like the best way to do this yet you really don't want to fire one after the other I don't think
[self.draggableDelegate dragAndDropTableViewController:self draggingGestureDidEnd:gesture];
[self.dropableDelegate dragAndDropTableViewController:self droppedGesture:gesture];
[self.tableView setScrollEnabled:YES];
[self.tableView reloadData];
}
break;
// case UIGestureRecognizerStateCancelled:
// case UIGestureRecognizerStateFailed:
// case UIGestureRecognizerStatePossible:
// [self.dragAndDropDelegate dragAndDropTableViewController:self draggingGesture:gesture endedForItem:nil];
break;
default:
break;
}
}
你可以找到这个的来源。我花了很长时间才把它做好,所以我真的希望这能节省别人的时间