我正在尝试创建一种效果，其中文本框消失，并且使用CGAffineTransform使collectionView向上滑动。这是有问题的代码
func scrollViewDidScroll(_ scrollView: UIScrollView) {
print("The scroll view began decelerating")
if self.lastContentOffset > self.collectionView.contentOffset.y && self.collectionView.contentOffset.y > 0{
print("you scrolled up:\t\(self.lastContentOffset)")
lastContentOffset = self.collectionView.contentOffset.y
self.feedSearchBar.isHidden = false
UIView.animate(withDuration: 0.25, animations: {
self.collectionView.transform = CGAffineTransform(translationX: 0, y: self.feedSearchBar.bounds.height*0.75)
self.feedSearchBar.isHidden = false
}, completion: nil)
}
else if self.lastContentOffset < self.collectionView.contentOffset.y && self.collectionView.contentOffset.y < self.collectionView.bounds.height{
print("you scrolled down:\t\(self.lastContentOffset)")
lastContentOffset = self.collectionView.contentOffset.y
self.feedSearchBar.isHidden = true
self.collectionView.frame.size = CGSize(width: self.collectionView.bounds.width, height: self.collectionView.bounds.height+5)
UIView.animate(withDuration: 0.25, animations: {
self.collectionView.transform = CGAffineTransform(translationX: 0, y: -self.feedSearchBar.bounds.height*0.75)
self.collectionView.frame = CGRect(x: self.collectionView.frame.minX, y: self.collectionView.frame.minY, width: self.collectionView.frame.width, height: self.collectionView.frame.height+self.feedSearchBar.bounds.height*0.75 )
self.feedSearchBar.isHidden = true
}, completion: nil)
}
else{
print("no difference")
}
}
我不确定为什么在调整collectionView框架的大小后代码会冻结。我尝试过在不调整框架大小的情况下编写代码，但很快的结果是，屏幕底部下方出现了白色条。
这是全部代码
import UIKit
class ViewController: UIViewController,UICollectionViewDelegate, UICollectionViewDataSource,UICollectionViewDelegateFlowLayout,UITextFieldDelegate {
var genericTagsArray:[String] = ["tag1","tag2","tag3","tag4","tag5","tag6","tag7","tag8","tag9","tag10","tag11","tag12","A","B","C","D","E","F","G","Ab","Abc","za","tag1","tag2","tag3","tag4","tag5","tag6","tag7","tag8","tag9","tag10","tag11","tag12","A","B","C","D","E","F","G","Ab","Abc","za"]
var currentTagsArray:[String] = [String]()
var tagsSelected:[String] = [String]()
let keyboardSlider = KeyboardSlider()
//@IBOutlet weak var feedSearchBar: UISearchBar!
@IBOutlet weak var collectionView: UICollectionView!
@IBOutlet weak var feedSearchBar: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
keyboardSlider.subscribeToKeyboardNotifications(view: view)
feedSearchBar.delegate = self
currentTagsArray = genericTagsArray
feedSearchBar.autocorrectionType = .no
feedSearchBar.keyboardType = .default
feedSearchBar.addTarget(self, action: #selector(ViewController.textFieldDidChange), for: .editingChanged)
let viewTapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(viewTapped(gestureRecognizer:)))
viewTapGestureRecognizer.cancelsTouchesInView = false
self.collectionView.addGestureRecognizer(viewTapGestureRecognizer)
//
collectionView.delegate = self
collectionView.dataSource = self
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 5, left: 1, bottom: 0, right: 1)
// layout.itemSize = CGSize(width: collectionView.bounds.width/3, height: collectionView.bounds.width/3 )
// layout.minimumInteritemSpacing = 0
layout.minimumLineSpacing = 0
collectionView.collectionViewLayout = layout
//Styling the Search Bar
self.feedSearchBar.borderStyle = .roundedRect
self.feedSearchBar.layer.borderColor = UIColor.black.cgColor
self.feedSearchBar.layer.borderWidth = 4
var searchBarHeight = self.feedSearchBar.bounds.height
self.feedSearchBar.frame = CGRect(x: 20, y: feedSearchBar.frame.maxY, width: self.collectionView.bounds.width, height: searchBarHeight*2)
self.feedSearchBar.placeholder = "Tap To Search"
self.feedSearchBar.returnKeyType = .search
//Code to add magnifying glass on right side
//looking lgass
// let imageView = UIImageView()
// let magnifyingGlassImage = UIImage(named: "magnifyingGlass")
// imageView.image = magnifyingGlassImage
// //arrange the frame according to your textfield height and image aspect
// imageView.frame = CGRect(x: 0, y: 5, width: 45, height: 20)
// imageView.contentMode = .ScaleAspectFit
// txtField.leftViewMode = .Always
// txtField.leftView = imageView
self.feedSearchBar.rightViewMode = .always
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return currentTagsArray.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "feedViewCell", for: indexPath) as! feedViewCell
cell.feedCellImageView.backgroundColor = .blue
cell.feedCellImageView.clipsToBounds = true
cell.feedCellImageView.layer.cornerRadius = CGFloat((cell.feedCellImageView.frame.width)/5)
// cell.feedCellImageView.layer.borderWidth = 2
// cell.feedCellImageView.layer.borderColor = UIColor.green.cgColor
//cell.feedCellLabel.text = "Tags Go Here this is a really long tag that will exceed the bounds"
cell.feedCellLabel.text = currentTagsArray[indexPath.item]
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("item: \(indexPath.item)\n\ttag: \(currentTagsArray[indexPath.item])")
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat{
return 0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
// Number of cells
let collectionViewWidth = collectionView.bounds.width/4.0
let collectionViewHeight = collectionViewWidth
return CGSize(width: collectionViewWidth-4, height: collectionViewHeight+25)
}
//New stuff
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder()
// currentGenericArray = genericArray.filter({letter -> Bool in
// letter.lowercased().contains(searchBar.text!)
// })
// if currentGenericArray.isEmpty{
// print("This element is not in the current array")
// }
collectionView.reloadData()
return true
}
/// Helper to dismiss keyboard
@objc func didStopEditing() {
// textFieldShouldReturn(phoneNumberTextField)
}
func textFieldDidEndEditing(_ textField: UITextField) {
UIView.setAnimationCurve(UIViewAnimationCurve.easeInOut)
UIView.animate(withDuration: 0.2) {
self.view.frame.origin.y = 0
}
}
@objc func textFieldDidChange(){
print("inside of text field did change")
guard(!(feedSearchBar.text?.isEmpty)!) else{
print("The search bar is empty")
currentTagsArray = genericTagsArray
collectionView.reloadData()
return
}
print("The search bar was not empty it says: \(feedSearchBar.text)")
currentTagsArray = genericTagsArray.filter({letter -> Bool in
//letter.lowercased().contains(searchBar.text!)
//mew stuff
if feedSearchBar.text!.count > letter.count{
return false
}
let stringRange = letter.index(letter.startIndex, offsetBy: feedSearchBar.text!.count)
let subword = letter[..<stringRange]
return subword.lowercased().contains(feedSearchBar.text!.lowercased())
//
//If broken delete above and uncoment below
//letter.lowercased().contains(searchBar.text!.lowercased())
})
if currentTagsArray.isEmpty{
currentTagsArray.insert(feedSearchBar.text!, at: 0)
}
collectionView.reloadData()
}
var lastContentOffset:CGFloat = 0
// func scrollViewWillBeginDecelerating(_ scrollView: UIScrollView) {
// print("The scroll view began decelerating")
// self.feedSearchBar.isHidden = true
// if self.lastContentOffset > self.collectionView.contentOffset.y{
// print("you scrolled up")
// self.feedSearchBar.isHidden = false
// }
// else if self.lastContentOffset < self.collectionView.contentOffset.y{
// print("you scrolled down")
// self.feedSearchBar.isHidden = true
// }
// else{
// self.feedSearchBar.isHidden = false
// }
// }
func scrollViewDidScroll(_ scrollView: UIScrollView) {
print("The scroll view began decelerating")
// self.feedSearchBar.isHidden = true
if self.lastContentOffset > self.collectionView.contentOffset.y && self.collectionView.contentOffset.y > 0{
print("you scrolled up:\t\(self.lastContentOffset)")
lastContentOffset = self.collectionView.contentOffset.y
// // print("you scrolled up")
self.feedSearchBar.isHidden = false
UIView.animate(withDuration: 0.25, animations: {
self.collectionView.transform = CGAffineTransform(translationX: 0, y: self.feedSearchBar.bounds.height*0.75)
self.feedSearchBar.isHidden = false
}, completion: nil)
// self.collectionView.frame.size = CGSize(width: self.collectionView.bounds.width, height: self.collectionView.bounds.height-5)
}
else if self.lastContentOffset < self.collectionView.contentOffset.y && self.collectionView.contentOffset.y < self.collectionView.bounds.height{
print("you scrolled down:\t\(self.lastContentOffset)")
lastContentOffset = self.collectionView.contentOffset.y
self.feedSearchBar.isHidden = true
self.collectionView.frame.size = CGSize(width: self.collectionView.bounds.width, height: self.collectionView.bounds.height+5)
UIView.animate(withDuration: 0.25, animations: {
self.collectionView.transform = CGAffineTransform(translationX: 0, y: -self.feedSearchBar.bounds.height*0.75)
// self.collectionView.frame.size = CGSize(width: self.collectionView.bounds.width, height: self.collectionView.bounds.height+5)
self.collectionView.frame = CGRect(x: self.collectionView.frame.minX, y: self.collectionView.frame.minY, width: self.collectionView.frame.width, height: self.collectionView.frame.height+self.feedSearchBar.bounds.height*0.75 )
self.feedSearchBar.isHidden = true
}, completion: nil)
}
else{
print("no difference")
}
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardFrameChangeNotification(notification:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)
}
var offsetY:CGFloat = 0
@objc func keyboardFrameChangeNotification(notification: Notification) {
}
@objc func viewTapped(gestureRecognizer:UIGestureRecognizer){
if feedSearchBar.isFirstResponder{
feedSearchBar.resignFirstResponder()
}
}
}
class feedViewCell:UICollectionViewCell{
@IBOutlet weak var feedCellImageView: UIImageView!
@IBOutlet weak var feedCellLabel: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
feedCellLabel.translatesAutoresizingMaskIntoConstraints = false
feedCellImageView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
feedCellImageView.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
feedCellImageView.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true
feedCellImageView.bottomAnchor.constraint(equalTo: self.feedCellLabel.topAnchor).isActive = true
feedCellImageView.translatesAutoresizingMaskIntoConstraints = false
feedCellLabel.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
feedCellLabel.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true
feedCellLabel.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
feedCellLabel.topAnchor.constraint(equalTo: self.feedCellImageView.bottomAnchor).isActive = true
}
}
extension Notification.Name{
static let showKeyboard = Notification.Name("showKeyboard")
}
class KeyboardSlider: NSObject {
// variables to hold and process information from the view using this class
weak var view: UIView?
@objc func keyboardWillShow(notification: NSNotification) {
// method to move keyboard up
// view?.frame.origin.y = 0 - getKeyboardHeight(notification as Notification)
print("made it to keyboard will show")
}
func getKeyboardHeight(_ notification:Notification) -> CGFloat {
// get exact height of keyboard on all devices and convert to float value to return for use
let userInfo = notification.userInfo
let keyboardSize = userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue
return keyboardSize.cgRectValue.height
}
func subscribeToKeyboardNotifications(view: UIView) {
// assigning view to class' counterpart
self.view = view
// when UIKeyboardWillShow do keyboardWillShow function
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: .UIKeyboardWillShow, object: nil)
}
func unsubscribeFromKeyboardNotifications() {
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: nil)
}
}