Drag uiimage to another uiimageview

Question

I am using the following code snippet to drag and drop uiimageview

UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(move:)]; [panRecognizer setMinimumNumberOfTouches:1]; [panRecognizer setMaximumNumberOfTouches:1]; [panRecognizer setDelegate:self]; [myImageView addGestureRecognizer:panRecognizer]; -(void)move:(id)sender { CGPoint translatedPoint = [(UIPanGestureRecognizer*)sender translationInView:self.view]; if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan) { firstX = [myImageView center].x; firstY = [myImageView center].y; } translatedPoint = CGPointMake(firstX+translatedPoint.x, firstY+translatedPoint.y); [myImageView setCenter:translatedPoint]; } 

This code is dragging and dropping all myImageView, but my requirement is to simply drag and drop uiimage and move it to another uiimagview.myImageView file, which should remain the same as after drag and drop. I just need to drag the myImageView layer. transparent. Any ideas would be appreciated.

Answer 1

I have made little effort to achieve your result. try

Step 1 : Define these 3 variables in your .h file

 UIImageView *ivSource1, *ivDestination2, *tempIV; 

Step 2 : Initialize all three UIImageView and add text to your ViewController in the viewDidLoad method

 ivSource1 = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"1.jpg"]]; [ivSource1 setFrame:CGRectMake(100, 100, 100, 100)]; [ivSource1 setTag:100]; [ivSource1 setUserInteractionEnabled:YES]; [self.view addSubview:ivSource1]; ivDestination2 = [[UIImageView alloc] init]; [ivDestination2 setFrame:CGRectMake(200, 300, 100, 100)]; [ivDestination2 setTag:101]; [ivDestination2 setUserInteractionEnabled:YES]; [self.view addSubview:ivDestination2]; tempIV = [[UIImageView alloc] init]; [tempIV setFrame:CGRectMake(0, 300, 100, 100)]; [tempIV setTag:102]; [tempIV setUserInteractionEnabled:YES]; [self.view addSubview:tempIV]; 

Step 3 : Define the following touch methods to handle the movement of the image to drag

 -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; if([[touch view] tag] == 100) { [tempIV setImage:ivSource1.image]; [tempIV setCenter:[touch locationInView:self.view]]; } } - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; [tempIV setCenter:[touch locationInView:self.view]]; } - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; [tempIV setCenter:[touch locationInView:self.view]]; if(CGRectContainsPoint(ivDestination2.frame, [touch locationInView:self.view])) { [ivDestination2 setImage:tempIV.image]; } // Remove image from dragable view [tempIV setImage:[UIImage imageNamed:@""]]; } 

Answer 2

With iOS 11, you can use Drag and Drop and copy / paste the API to perform a drag and drop UIImage operation from one UIImageView to another UIImageView . According to your needs, you can choose one of the following two implementations of Swift 4.

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# 1. Using UIDragInteraction , UIDragInteractionDelegate and UIPasteConfiguration

 import UIKit class ViewController: UIViewController { let imageView1 = UIImageView() let imageView2 = UIImageView() override func viewDidLoad() { super.viewDidLoad() imageView1.image = UIImage(named: "image") imageView1.contentMode = .scaleAspectFit imageView1.isUserInteractionEnabled = true let dragInteraction = UIDragInteraction(delegate: self) dragInteraction.isEnabled = true imageView1.addInteraction(dragInteraction) imageView2.contentMode = .scaleAspectFit imageView2.isUserInteractionEnabled = true let configuration = UIPasteConfiguration(forAccepting: UIImage.self) imageView2.pasteConfiguration = configuration let stackView = UIStackView(arrangedSubviews: [imageView1, imageView2]) view.addSubview(stackView) stackView.distribution = .fillEqually stackView.frame = view.bounds stackView.autoresizingMask = [.flexibleWidth, .flexibleHeight] } override func paste(itemProviders: [NSItemProvider]) { _ = itemProviders.first?.loadObject(ofClass: UIImage.self, completionHandler: { (image: NSItemProviderReading?, error: Error?) in DispatchQueue.main.async { self.imageView2.image = image as? UIImage } }) } } 

 extension ViewController: UIDragInteractionDelegate { func dragInteraction(_ interaction: UIDragInteraction, itemsForBeginning session: UIDragSession) -> [UIDragItem] { guard let image = imageView1.image else { return [] } let item = UIDragItem(itemProvider: NSItemProvider(object: image)) return [item] } } 

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# 2. Using UIDragInteraction , UIDragInteractionDelegate , UIDropInteraction and UIDropInteractionDelegate

 import UIKit class ViewController: UIViewController { let imageView1 = UIImageView() let imageView2 = UIImageView() override func viewDidLoad() { super.viewDidLoad() imageView1.image = UIImage(named: "image") imageView1.contentMode = .scaleAspectFit imageView1.isUserInteractionEnabled = true imageView2.contentMode = .scaleAspectFit imageView2.isUserInteractionEnabled = true let dragInteraction = UIDragInteraction(delegate: self) dragInteraction.isEnabled = true imageView1.addInteraction(dragInteraction) let dropInteraction = UIDropInteraction(delegate: self) imageView2.addInteraction(dropInteraction) let stackView = UIStackView(arrangedSubviews: [imageView1, imageView2]) view.addSubview(stackView) stackView.distribution = .fillEqually stackView.frame = view.bounds stackView.autoresizingMask = [.flexibleWidth, .flexibleHeight] } } 

 extension ViewController: UIDragInteractionDelegate { func dragInteraction(_ interaction: UIDragInteraction, itemsForBeginning session: UIDragSession) -> [UIDragItem] { guard let image = imageView1.image else { return [] } let item = UIDragItem(itemProvider: NSItemProvider(object: image)) item.localObject = image return [item] } } 

 extension ViewController: UIDropInteractionDelegate { func dropInteraction(_ interaction: UIDropInteraction, canHandle session: UIDropSession) -> Bool { return session.canLoadObjects(ofClass: UIImage.self) && session.items.count == 1 } func dropInteraction(_ interaction: UIDropInteraction, sessionDidUpdate session: UIDropSession) -> UIDropProposal { let dropLocation = session.location(in: view) let operation: UIDropOperation if imageView2.frame.contains(dropLocation) { operation = session.localDragSession == nil ? .copy : .move } else { operation = .cancel } return UIDropProposal(operation: operation) } func dropInteraction(_ interaction: UIDropInteraction, performDrop session: UIDropSession) { session.loadObjects(ofClass: UIImage.self) { imageItems in guard let images = imageItems as? [UIImage] else { return } self.imageView2.image = images.first } } } 

Answer 3

About # 1. Using UIDragInteraction, UIDragInteractionDelegate, and UIPasteConfiguration , thanks for this code, which works great, but only between the two views . I cannot handle 4 or more views, especially for setting "imageView1" or "imageView2" or "imageViewX" or "Y" to "override func paste" and func dragInteraction. Can you give some information, please. Thank you for your help.