使CollectionViewCell已按下

Question

我有一个带有服务的控制器，我希望我的第一个服务看起来应该已经按下了。不知道该怎么做。我尝试了方法WillDisplay和什么都没有。在cellForItemAt中也尝试过第一个单元格isSelected = true。一样的。不管用。

在这里输入图像描述

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    let cell = collectionView.cellForItem(at: indexPath) as? ServiceCollectionViewCell
    let models = self.serviceModel[indexPath.row]

    switch models {
    case .haircut:
        self.pricingModel?.haircut = true
        cell?.setSelected()
        print(pricingModel?.haircut as Any)
    case .babyHaircut:
        self.pricingModel?.babyHaircut = true
        cell?.setSelected()
        print(pricingModel?.babyHaircut as Any)
    case .beardHaircut:
        self.pricingModel?.beardHaircut = true
        cell?.setSelected()
        print(pricingModel?.beardHaircut as Any)
    case .straightRazor:
        self.pricingModel?.straightRazor = true
        cell?.setSelected()
        print(pricingModel?.straightRazor as Any)
    case .clipper:
        self.pricingModel?.clipper = true
        cell?.setSelected()
        print(pricingModel?.clipper as Any)
    case .stacking:
        self.pricingModel?.stacking = true
        cell?.setSelected()
        print(pricingModel?.stacking as Any)
    }
}


func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
        let cell = collectionView.cellForItem(at: indexPath) as? ServiceCollectionViewCell
        let models = self.serviceModel[indexPath.row]

        switch models {
        case .haircut:
            self.pricingModel?.haircut = false
            cell?.setUnselected()
            print(pricingModel?.haircut as Any)
        case .babyHaircut:
            self.pricingModel?.babyHaircut = false
            cell?.setUnselected()
            print(pricingModel?.babyHaircut as Any)
        case .beardHaircut:
            self.pricingModel?.beardHaircut = false
            cell?.setUnselected()
             print(pricingModel?.beardHaircut as Any)
        case .straightRazor:
            self.pricingModel?.straightRazor = false
            cell?.setUnselected()
            print(pricingModel?.straightRazor as Any)
        case .clipper:
            self.pricingModel?.clipper = false
            cell?.setUnselected()
            print(pricingModel?.clipper as Any)
        case .stacking:
            self.pricingModel?.stacking = false
            cell?.setUnselected()
            print(pricingModel?.stacking as Any)
    }
}

这里是我的代码

Answer 1

下面是一个示例，当视图第一次加载时，我希望它显示蓝色，即项目1。

let dataSource = ["Red", "Blue", "Purple", "Brown"]

override func viewDidLoad() { // or viewWillAppear depending on your needs
    super.viewDidLoad()

    autoShowPreselectedCell()
}

func autoShowPreselectedCell() {

    let blueItem = dataSource[1]

    // 1. Create an IndexPath using the item and section. For this example there is only 1 section
    let preSelectedIndexPath = IndexPath(item: blueItem, section: 0)

    // 2. this is where it preselects
    yourCollectionView.selectItem(at: preSelectedIndexPath, animated: false, scrollPosition: .centeredHorizontally)
    collectionView(self.yourCollectionView, didSelectItemAt: preSelectedIndexPath)
}