[英]Manipulate uicollectionview inside uicollectionviewcell from uiviewcontroller
I have a UIViewController containing a UICollectionView and within their UICollectionViewCell is embedded another UICollectionView structure 我有一个包含UICollectionView的UIViewController,并且在其UICollectionViewCell中嵌入了另一个UICollectionView 结构
And visually looks like this: visually 而且在视觉上看起来是这样的: 视觉
I want to press BOTON in UIViewController and from there, change the backgroundColor of UICollectionView inside the cell of the outter UICollectionView 我想在UIViewController中按BOTON,然后从那里在外部UICollectionView的单元格内更改UICollectionView的backgroundColor
My UIViewController class 我的UIViewController类
class ViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
@IBOutlet weak var scrollH: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
if let flowLayout = scrollH.collectionViewLayout as? UICollectionViewFlowLayout {
flowLayout.minimumLineSpacing = 0
}
setupMenuQuestion()
}
var uiview: UIView = {
let view1 = UIView()
view1.backgroundColor = UIColor.brown
return view1
}()
var uibutton: UIButton = {
let btn1 = UIButton()
btn1.setTitle("BOTON", for: .normal)
btn1.addTarget(self, action: #selector(presionoBoton), for: .touchUpInside)
return btn1
}()
@objc func presionoBoton() {
delegateExterior?.cambiarBackground()
}
var delegateExterior: ExteriorCollectionViewCellDelegate?
private func setupMenuQuestion() {
view.addSubview(uiview)
uiview.translatesAutoresizingMaskIntoConstraints = false
uiview.leftAnchor.constraint(equalTo: view.leftAnchor, constant: 0).isActive = true
uiview.rightAnchor.constraint(equalTo: view.rightAnchor, constant: 0).isActive = true
uiview.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0).isActive = true
uiview.heightAnchor.constraint(equalToConstant: 30).isActive = true
uibutton.translatesAutoresizingMaskIntoConstraints = false
uiview.addSubview(uibutton)
uibutton.centerYAnchor.constraint(equalTo: uiview.centerYAnchor).isActive = true
uibutton.centerXAnchor.constraint(equalTo: uiview.centerXAnchor).isActive = true
uibutton.leftAnchor.constraint(equalTo: uiview.leftAnchor, constant: 7).isActive = true
uibutton.rightAnchor.constraint(equalTo: uiview.rightAnchor, constant: -7).isActive = true
uibutton.heightAnchor.constraint(equalTo: uiview.heightAnchor, multiplier: 0.8).isActive = true
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cellNumQuestion = collectionView.dequeueReusableCell(withReuseIdentifier: "celdaExterior", for: indexPath) as! ExteriorCollectionViewCell
return cellNumQuestion
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: view.frame.height - 100)
}
}
My UICollectionViewCell Class 我的UICollectionViewCell类
protocol ExteriorCollectionViewCellDelegate {
func cambiarBackground()
}
class ExteriorCollectionViewCell: UICollectionViewCell,
UICollectionViewDataSource, UICollectionViewDelegate,
UICollectionViewDelegateFlowLayout, ExteriorCollectionViewCellDelegate{
func cambiarBackground() {
collectionCelda.backgroundColor = UIColor.black
}
@IBOutlet weak var collectionCelda: UICollectionView!
override init(frame: CGRect) {
super.init(frame: frame)
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.minimumInteritemSpacing = 40
layout.minimumLineSpacing = 40
collectionCelda!.collectionViewLayout = layout
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 4
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
var cell = UICollectionViewCell()
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "celdaInterior", for: indexPath)
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: frame.width - 20, height: 400)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 30.0, left: 0.0, bottom: 30.0, right: 0.0)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 40
}
}
I have seen another post similar to my problem but I do not know how to proceed 我看过另一则与我的问题类似的帖子,但我不知道如何继续
How to access a collectionView that is embedded in a parent collectionViewCell in the main UIViewController? 如何访问嵌入在主UIViewController的父collectionViewCell中的collectionView?
In your case, you didn't set the delegate you've created, you should set it inside: 在您的情况下,您未设置已创建的委托,应在内部设置它:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cellNumQuestion = collectionView.dequeueReusableCell(withReuseIdentifier: "celdaExterior", for: indexPath) as! ExteriorCollectionViewCell
// Setting the delegate
delegateExterior = cellNumQuestion
return cellNumQuestion
}
Also, in order to avoid reference-cycle set your delegateExterior pointer to be weak: 另外,为了避免引用循环,请将您的委托外部指针设置为弱:
weak var delegateExterior: ExteriorCollectionViewCellDelegate?
Another solution will be to add an observer inside ExteriorCollectionViewCell
and when the button is tapped and the IBAction method gets called inside your UIViewController
, use post notification to pass that event into your observer. 另一个解决方案是在ExteriorCollectionViewCell
添加一个观察者 ,并在点击按钮并在UIViewController
内部调用IBAction方法时,使用后通知将该事件传递给观察者。
ie: 即:
Add the observer that will listen to your events inside your ExteriorCollectionViewCell
: 添加观察者,该观察者将侦听您的ExteriorCollectionViewCell
的事件:
NotificationCenter.default.addObserver(forName: NSNotification.Name(rawValue: "EventForCollectionView"),
object: nil,
queue: nil) { [weak self] (_) in
// This method will be invoked when you post notification from your IBAction method inside your UIVC
self?.YourCustomMethod()
}
Send your notification event from your IBAction inside the IBAction method: 通过IBAction方法中的IBAction发送通知事件:
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "EventForCollectionView"), object: nil)
But if the button is inside your UICollectionViewCell
you can just use IBAction method inside your UICollectionViewCell
and do your logic there. 但是,如果按钮在UICollectionViewCell
,则可以在UICollectionViewCell
内使用IBAction方法,并在那里进行逻辑处理。
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