我们希望在单击 cell collection 中的项目(即 ImageView)时通过替换主 Controller 来显示另一个 Controller 。但是我们无法获得主 Collection View ，也无法导航目标 Controller 。我们正在使用以下方法-

HomeViewComtroller.swift

import LBTAComponents

class HomeViewController: DatasourceController {

    override func viewDidLoad() {
        super.viewDidLoad()
        navigationItem.title = "Home"
        collectionView?.contentInset = UIEdgeInsetsMake(50, 0, 0, 0)
        collectionView?.scrollIndicatorInsets = UIEdgeInsetsMake(50, 0, 0, 0)
        collectionView?.backgroundColor = UIColor(r: 232, g: 236, b: 241, a: 1)
        let homeViewDatasource = HomeViewDatasource()
        self.datasource = homeViewDatasource
    }


    override func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {

        if indexPath.section == 0 {
            return CGSize(width: view.frame.width, height: 120)
        } else if indexPath.section == 6 {
            return CGSize(width: view.frame.width, height: 120)
        } else {
             return CGSize(width: view.frame.width, height: 200)
            }


    }
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
            return CGSize(width: view.frame.width, height: 33)
    }
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForFooterInSection section: Int) -> CGSize {
        return CGSize(width: view.frame.width, height: 10)
    }


//    lazy var homeMainCatgCell: HomeMainCatgCell = {
//        let homemain = HomeMainCatgCell ()
//        homemain.homeViewcontroller = self
//        return homemain
//    }()


    func handleCtgClick (ctgname: String ,ctgId: String) {

        let dummySettingViewController = UIViewController()
        dummySettingViewController.view.backgroundColor = UIColor.white
        dummySettingViewController.navigationItem.title = ctgname
        navigationController?.navigationBar.tintColor = UIColor.white
        navigationController?.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.white]
        navigationController?.pushViewController(dummySettingViewController, animated: true)

    }

}

HomeViewDatasource

import LBTAComponents

class HomeViewDatasource: Datasource {

    override func headerClasses() -> [DatasourceCell.Type]? {
         return [HomeMainCatgCellHeader.self,HomeSaleCatgCellHeader.self,HomeNewArrivalCellHeader.self,HomeBestSallingCellHeader.self,HomeBigDiscountCellHeader.self,HomeSpecialOfferCellHeader.self,HomeBrandCellHeader.self]
    }
    override func footerClasses() -> [DatasourceCell.Type]? {
        return[HomeCellsFooter.self]
    }
    override func cellClasses() -> [DatasourceCell.Type] {
        return [HomeMainCatgCell.self,HomeSaleCtagCell.self,HomeNewArrivalsCell.self,HomeBestSallingCatgCell.self,HomeBigDiscountCatgCell.self,HomeSpecialOfferCatgCell.self,HomeBrandVIewCell.self]
    }
    override func numberOfItems(_ section: Int) -> Int {
        return 1
    }
    override func numberOfSections() -> Int {
        return 7
    }
}

HomeMainCatgCell.swift

import LBTAComponents

class HomeMainCatgCell: DatasourceCell {
    var homeViewcontroller: HomeViewController?
    let personalcareCatgImageView: UIImageView = {
        let iv = UIImageView()
        iv.image = #imageLiteral(resourceName: "personalcareimage")
        iv.tag = 0
        iv.contentMode = .scaleToFill
        return iv
    }()

    let healthcareCatgImageView: UIImageView = {
        let iv = UIImageView()
        iv.image = #imageLiteral(resourceName: "healthcareimage")
        iv.contentMode = .scaleToFill
        iv.tag = 1
        return iv
    }()

    let homecareCatgImageView: UIImageView = {
        let iv = UIImageView()
        iv.image = #imageLiteral(resourceName: "homecareimage")
        iv.contentMode = .scaleToFill
        iv.tag = 2
        return iv
    }()

    let kitchencareCatgImageView: UIImageView = {
        let iv = UIImageView()
        iv.image = #imageLiteral(resourceName: "kitchencareiamge")
        iv.contentMode = .scaleToFill
        iv.tag = 3
        return iv
    }()


    override func setupViews() {
        super.setupViews()
        let personalcareCatgImageContainerView = UIView()
        personalcareCatgImageContainerView.backgroundColor = .white

        let homecareCatgImageContainerView = UIView()
        homecareCatgImageContainerView.backgroundColor = .white


        let healthcareCatgImageContainerView = UIView()
        healthcareCatgImageContainerView.backgroundColor = .white


        let kitchencareCatgImageContainerView = UIView()
        kitchencareCatgImageContainerView.backgroundColor = .white


        let imageStackView = UIStackView(arrangedSubviews: [personalcareCatgImageContainerView,homecareCatgImageContainerView,healthcareCatgImageContainerView,kitchencareCatgImageContainerView])
        imageStackView.axis = .horizontal
        imageStackView.distribution = .fillEqually
        addSubview(imageStackView)
        imageStackView.anchor(topAnchor, left: leftAnchor, bottom: self.bottomAnchor, right: self.rightAnchor, topConstant: 0, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: frame.width, heightConstant: frame.height)

        imageStackView.addSubview(personalcareCatgImageView)
        imageStackView.addSubview(healthcareCatgImageView)
        imageStackView.addSubview(homecareCatgImageView)
        imageStackView.addSubview(kitchencareCatgImageView)

        personalcareCatgImageView.anchor(personalcareCatgImageContainerView.topAnchor, left: personalcareCatgImageContainerView.leftAnchor, bottom: personalcareCatgImageContainerView.bottomAnchor, right: personalcareCatgImageContainerView.rightAnchor, topConstant: 5, leftConstant: 5, bottomConstant: 5, rightConstant: 5, widthConstant: personalcareCatgImageContainerView.frame.width , heightConstant: personalcareCatgImageContainerView.frame.width)

          healthcareCatgImageView.anchor(healthcareCatgImageContainerView.topAnchor, left: healthcareCatgImageContainerView.leftAnchor, bottom: healthcareCatgImageContainerView.bottomAnchor, right: healthcareCatgImageContainerView.rightAnchor, topConstant: 5, leftConstant: 5, bottomConstant: 5, rightConstant: 5, widthConstant: healthcareCatgImageContainerView.frame.width , heightConstant: healthcareCatgImageContainerView.frame.width)

          homecareCatgImageView.anchor(homecareCatgImageContainerView.topAnchor, left: homecareCatgImageContainerView.leftAnchor, bottom: homecareCatgImageContainerView.bottomAnchor, right: homecareCatgImageContainerView.rightAnchor, topConstant: 5, leftConstant: 5, bottomConstant: 5, rightConstant: 5, widthConstant: homecareCatgImageContainerView.frame.width , heightConstant: homecareCatgImageContainerView.frame.width)

          kitchencareCatgImageView.anchor(kitchencareCatgImageContainerView.topAnchor, left: kitchencareCatgImageContainerView.leftAnchor, bottom: kitchencareCatgImageContainerView.bottomAnchor, right: kitchencareCatgImageContainerView.rightAnchor, topConstant: 5, leftConstant: 5, bottomConstant: 5, rightConstant: 5, widthConstant: kitchencareCatgImageContainerView.frame.width , heightConstant: kitchencareCatgImageContainerView.frame.width)

        personalcareCatgImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleClickCtg)))
        personalcareCatgImageView.isUserInteractionEnabled = true
        healthcareCatgImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleClickCtg)))
        healthcareCatgImageView.isUserInteractionEnabled = true
        homecareCatgImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleClickCtg)))
        homecareCatgImageView.isUserInteractionEnabled = true
        kitchencareCatgImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleClickCtg)))
        kitchencareCatgImageView.isUserInteractionEnabled = true
    }

    func handleClickCtg(gestureRecognizer: UITapGestureRecognizer) {
        var CtgName: String? = nil
        var CtgId: String? = nil
        guard let tag = gestureRecognizer.view?.tag else {return}
        print(tag)
        switch tag {
        case 0:
            CtgName = "Personal Care"
            CtgId = "121"
        case 1:
            CtgName = "Health Care"
            CtgId = "122"
        case 2:
            CtgName = "Home Care"
            CtgId = "123"
        case 3:
            CtgName = "Kitchen Care"
            CtgId = "124"
        default:
            return
        }
        self.homeViewController?.handleCtgClick(ctgname: CtgName! ,ctgId: CtgId!)
    }  
}

主要问题

首先，我没有绑定(bind)整个单元格的点击，我只想点击单元格内的 ImageView。因此，为此我将 GestureRecognizer 绑定(bind)到 ImageView 上，例如 -

kitchencareCatgImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleClickCtg)))

Click 事件工作正常，因为它通过 print(tag) 在 click 函数中打印标签(添加到 ImageView 中)。但是当调用函数self.homeViewcontroller.handleCtgClick(ctgname: CtgName!,ctgId: CtgId!)时(函数存在于HomeViewcontroller类中)。它不会更改 View Controller 。

我还调试了 handleCtgClick 函数，我发现我得到的 HomeViewcontroller 的对象是 nil。

提前致谢

最佳答案

如果您在单元类中声明 Controller 的全局实例，这将创建一个引用循环并在您的应用程序中创建一个泄漏。您的单元格将强烈引用您的 Controller ，而您的 Controller 将强烈引用您的 tableview，这反过来又保持对单元格的强烈引用，其次，如果您可能无法分辨被单击单元格的索引路径允许编辑。您可以尝试以下方法来解决这两个问题。

首先，在您的单元格类中创建一个枚举，其中包含根据您的 ImageView 命名的案例，以便您的 Controller 知道单击了哪个 ImageView ，并且您也可以将您的标签链接到它。像这样的东西:

enum CategoryViews:Int{
    case personal = 0,healthcare = 1,homecare = 2,kitchencare = 3
}

然后在您的单元格类中创建一个协议(protocol)，例如:

protocol HomeMainCatgCellDelegate:class{
   func clicked(view:CategoryViews,forCell cell:HomeMainCatgCell)
}

然后在您的单元类中创建一个弱变量并在您的操作处理程序方法中调用协议(protocol)方法

class HomeMainCatgCell: DatasourceCell {
     weak var delegate:HomeMainCatgCellDelegate?
     //Remove the variable var homeViewcontroller: HomeViewController? to avoid reference cycle and we don't need it anyway.
 ...
func handleClickCtg(gestureRecognizer: UITapGestureRecognizer) {
    guard let tag = gestureRecognizer.view?.tag else {return}
    print(tag)
    if let clickedImageView = CategoryViews(rawValue:tag){
        self.delegate?.clicked(view:clickedImageView,forCell:self)
    }
}  
}

然后在您的 View Controller 类中，您必须确认 HomeMainCatgCellDelegate 协议(protocol)并将单元格的委托(delegate)设置为 self 。

class HomeViewController: DatasourceController, HomeMainCatgCellDelegate{
...
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
//Dequeue your cell here
 cell.delegate = self
 ...
 return self
}
func clicked(view:CategoryViews,forCell cell:HomeMainCatgCell){
    //And you can handle your events accordingly here
    if let indexpath = self.collectionView.indexPath(for: cell){
    //Here you will get the indexpath of clicked cell and then you can put a switch condition to check which imageview is clicked
          switch view{
          case .personal:break
          case .healthcare:break
          case .homecare:break
          case .kitchencare:break
          }
    }
}
}

希望这对您有所帮助。

关于ios - 如何在使用 Swift 3 单击 collectionView 单元格内的项目时导航另一个 View Controller ，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/43510985/