如何创建类似于Safari的safari工具栏自定义的拖放 [英] How to create a drag and drop similar to safari toolbar customisation for iPad
本文介绍了如何创建类似于Safari的safari工具栏自定义的拖放的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
- （void）touchesBegan：（NSSet *）与Event：（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 center = [[touches anyObject] locationInView：self.view];
[self.draggedView setCenter：center];
[self.draggedView setAlpha：0.5];
[self.view addSubview：self.draggedView];
}
然而，在我尝试评估哪个UIView触摸结束的touchesEnded事件中当我放弃它时，我总是得到一个UIView而不是UITableView。任何想法都是非常受欢迎的。
解决方案
我想我已经使用最新的GestureRecognisers更好地解决了这个问题。我使用以下的基本TableView控制器中的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 *）手势{
UITableViewCell * cell =（UITableViewCell *）[手势视图];
开关（[手势状态]）{
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];
//切换视图与此相关联的手势将允许拖动的视图继续从单元格离开
[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;
//这似乎不是最好的方式来做到这一点，但你真的不想一个接一个地发火，我不认为
[self.draggableDelegate dragAndDropTableViewController：self draggingGestureDidEnd：手势];
[self.dropableDelegate dragAndDropTableViewController：self droppedGesture：gesture];
[self.tableView setScrollEnabled：YES];
[self.tableView reloadData];
}
break;
// case UIGestureRecognizerStateCancelled：
// case UIGestureRecognizerStateFailed：
// case UIGestureRecognizerStatePossible：
// [self.dragAndDropDelegate dragAndDropTableViewController：self dragingGesture：gesture endsForItem：nil ]。
break;
默认值：
break;
}
}
在扩展这个基类的TableView中，我添加跟随到cellForIndexPath TableViewDataSource中的每个单元格，
UILongPressGestureRecognizer * longPress = [[UILongPressGestureRecognizer alloc] initWithTarget：cell action：nil];
longPress.delegate = self;
[cell addGestureRecognizer：longPress];
最后，你需要做的就是实现这样的代理方法，
- （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 *）手势{
UITableViewCell * cell =（UITableViewCell *）[手势视图];
开关（[手势状态]）{
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];
//切换视图与此相关联的手势将允许拖动的视图继续从单元格离开
[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;
//这似乎不是最好的方式来做到这一点，但你真的不想一个接一个地发火，我不认为
[self.draggableDelegate dragAndDropTableViewController：self draggingGestureDidEnd：手势];
[self.dropableDelegate dragAndDropTableViewController：self droppedGesture：gesture];
[self.tableView setScrollEnabled：YES];
[self.tableView reloadData];
}
break;
// case UIGestureRecognizerStateCancelled：
// case UIGestureRecognizerStateFailed：
// case UIGestureRecognizerStatePossible：
// [self.dragAndDropDelegate dragAndDropTableViewController：self dragingGesture：gesture endsForItem：nil ]。
break;
默认值：
break;
}
}
你可以找到这个这里。花了我很长时间才能得到这个权利，所以我真的希望这可以节省别人的时间。
I have a UIViewController that has both a UITable and a UIView on it. I want to be able to pick up items that are displayed in the UIView and drop them on to a cell in the UITableView.I have had to revert to using touch events as opposed to the new UIGestureRecognisers to take a snap shot of the UIView tapped so that this snap shot is dragged over to the UITableView as opposed to the UIView touched. This works great using the following,
-(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];
}
However, in the touchesEnded event when I try to evaluate which UIView the touch ended on I always get a UIView instead of the UITableView when I drop on it. Any ideas would be very welcome.
解决方案
I think I have come up with better solution to this problem using the latest GestureRecognisers. I use the following LongPress Gesture Recogniser inside my base TableView Controller.
- (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;
}
}
In the TableViews that extend this base class I add the following to each cell in the cellForIndexPath TableViewDataSource,
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:cell action:nil];
longPress.delegate = self;
[cell addGestureRecognizer:longPress];
and finally all you need to do is implement the delegate methods like so,
- (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;
}
}
You can find the source for this here. It took me a long time to get this right so I really hope this saves someone else the time.
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