Swift UICollectionView 文本字段

Question

我有一堆 UITextFields 位于不同单元格(大约 7 个)的 Collection View 中。我正在寻找一种方法将验证这些字段的责任委托(delegate)给内部服务类。有没有一种方法可以在不导致 Controller 膨胀的情况下执行此操作？

我部分尝试的是创建一个对象，然后将文本字段委托(delegate)分配给该对象。但是，我很难将两者链接在一起(能够访问 textField.text 属性以验证输出并将其添加到结构中)。

是否有更清洁、更高效的方法，或者我正在寻找一个长 Controller ？

谢谢

Answer 1

特点

• 将 TextFields 中的数据保存在单元格中
• 检测编辑TextField的坐标
• 在 ViewController (MVC) 中找到 TextFields 处理程序
• 滚动时隐藏键盘

详情

xCode 8.3、 swift 3.1

完整示例

ViewController.swift

import UIKit

fileprivate var textFieldsTexts = [IndexPath:String]()

class ViewController: UIViewController {

    @IBOutlet weak var collectionView: UICollectionView!

    override func viewDidLoad() {
        super.viewDidLoad()
        setupCollectionView()
    }
}

extension ViewController: UICollectionViewDataSource {
    func setupCollectionView() {
        collectionView.dataSource = self
        collectionView.delegate = self
    }

    func numberOfSections(in collectionView: UICollectionView) -> Int {
        return 1
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 100
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CollectionViewCell", for: indexPath) as! CollectionViewCell
        cell.textField.placeholder = "\(indexPath)"
        cell.delegate = self
        return cell
    }
}

extension ViewController: UICollectionViewDelegate {
    func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
        let cell = cell as! CollectionViewCell
        cell.textField.text = textFieldsTexts[indexPath]
    }

    func scrollViewWillBeginDecelerating(_ scrollView: UIScrollView) {
        view.endEditing(true)
    }
}

extension ViewController: CollectionViewCellDelegate {

    func collectionViewCell(valueChangedIn textField: UITextField, delegatedFrom cell: CollectionViewCell) {
        if let indexPath = collectionView.indexPath(for: cell), let text = textField.text {
            print("textField text: \(text) from cell: \(indexPath))")
            textFieldsTexts[indexPath] = text
        }
    }

    func collectionViewCell(textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String, delegatedFrom cell: CollectionViewCell)  -> Bool {
        print("Validation action in textField from cell: \(String(describing: collectionView.indexPath(for: cell)))")
        return true
    }

}

CollectionViewCell.swift

import UIKit

class CollectionViewCell: UICollectionViewCell {

    @IBOutlet weak var textField: UITextField!
    var delegate: CollectionViewCellDelegate?

    override func awakeFromNib() {
        super.awakeFromNib()
        textField.delegate = self
    }

    @IBAction func valueChanged(_ sender: UITextField) {
        delegate?.collectionViewCell(valueChangedIn: textField, delegatedFrom: self)
    }
}

extension CollectionViewCell: UITextFieldDelegate {

    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        if let delegate = delegate {
            return delegate.collectionViewCell(textField: textField, shouldChangeCharactersIn: range, replacementString: string, delegatedFrom: self)
        }
        return true
    }
}

CollectionViewCellDelegate.swift

import UIKit

protocol CollectionViewCellDelegate {
    func collectionViewCell(valueChangedIn textField: UITextField, delegatedFrom cell: CollectionViewCell)
    func collectionViewCell(textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String, delegatedFrom cell: CollectionViewCell)  -> Bool
}

Main.storyboard

<?xml version="1.0" encoding="UTF-8"?>
<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="12118" systemVersion="16D32" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" colorMatched="YES" initialViewController="BYZ-38-t0r">
    <device id="retina4_7" orientation="portrait">
        <adaptation id="fullscreen"/>
    </device>
    <dependencies>
        <deployment identifier="iOS"/>
        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="12086"/>
        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
    </dependencies>
    <scenes>
        <!--View Controller-->
        <scene sceneID="tne-QT-ifu">
            <objects>
                <viewController id="BYZ-38-t0r" customClass="ViewController" customModule="stackoverflow_43143119" customModuleProvider="target" sceneMemberID="viewController">
                    <layoutGuides>
                        <viewControllerLayoutGuide type="top" id="y3c-jy-aDJ"/>
                        <viewControllerLayoutGuide type="bottom" id="wfy-db-euE"/>
                    </layoutGuides>
                    <view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                        <subviews>
                            <collectionView clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="scaleToFill" dataMode="prototypes" translatesAutoresizingMaskIntoConstraints="NO" id="KWt-KV-A2D">
                                <rect key="frame" x="0.0" y="28" width="375" height="639"/>
                                <color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                                <collectionViewFlowLayout key="collectionViewLayout" minimumLineSpacing="10" minimumInteritemSpacing="10" id="WoG-le-dkA">
                                    <size key="itemSize" width="100" height="50"/>
                                    <size key="headerReferenceSize" width="0.0" height="0.0"/>
                                    <size key="footerReferenceSize" width="0.0" height="0.0"/>
                                    <inset key="sectionInset" minX="0.0" minY="0.0" maxX="0.0" maxY="0.0"/>
                                </collectionViewFlowLayout>
                                <cells>
                                    <collectionViewCell opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" reuseIdentifier="CollectionViewCell" id="w5c-mF-XjG" customClass="CollectionViewCell" customModule="stackoverflow_43143119" customModuleProvider="target">
                                        <rect key="frame" x="0.0" y="0.0" width="100" height="50"/>
                                        <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
                                        <view key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center">
                                            <rect key="frame" x="0.0" y="0.0" width="100" height="50"/>
                                            <autoresizingMask key="autoresizingMask"/>
                                            <subviews>
                                                <textField opaque="NO" clipsSubviews="YES" contentMode="scaleToFill" contentHorizontalAlignment="left" contentVerticalAlignment="center" borderStyle="roundedRect" placeholder="text" textAlignment="natural" minimumFontSize="17" translatesAutoresizingMaskIntoConstraints="NO" id="HAy-QM-Eqi">
                                                    <rect key="frame" x="0.0" y="10" width="100" height="30"/>
                                                    <nil key="textColor"/>
                                                    <fontDescription key="fontDescription" type="system" pointSize="14"/>
                                                    <textInputTraits key="textInputTraits"/>
                                                    <connections>
                                                        <action selector="valueChanged:" destination="w5c-mF-XjG" eventType="editingChanged" id="qDf-D2-X1l"/>
                                                    </connections>
                                                </textField>
                                            </subviews>
                                        </view>
                                        <color key="backgroundColor" white="0.66666666666666663" alpha="1" colorSpace="calibratedWhite"/>
                                        <constraints>
                                            <constraint firstItem="HAy-QM-Eqi" firstAttribute="centerY" secondItem="w5c-mF-XjG" secondAttribute="centerY" id="JCH-09-Hsr"/>
                                            <constraint firstItem="HAy-QM-Eqi" firstAttribute="leading" secondItem="w5c-mF-XjG" secondAttribute="leading" id="YvF-Qw-sOW"/>
                                            <constraint firstAttribute="trailing" secondItem="HAy-QM-Eqi" secondAttribute="trailing" id="kPK-6X-Aug"/>
                                        </constraints>
                                        <connections>
                                            <outlet property="textField" destination="HAy-QM-Eqi" id="3tf-0f-agX"/>
                                        </connections>
                                    </collectionViewCell>
                                </cells>
                            </collectionView>
                        </subviews>
                        <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                        <constraints>
                            <constraint firstItem="KWt-KV-A2D" firstAttribute="top" secondItem="y3c-jy-aDJ" secondAttribute="bottom" constant="8" symbolic="YES" id="5Fe-R9-7li"/>
                            <constraint firstItem="KWt-KV-A2D" firstAttribute="bottom" secondItem="wfy-db-euE" secondAttribute="top" id="Rjm-Ij-0Pe"/>
                            <constraint firstAttribute="trailing" secondItem="KWt-KV-A2D" secondAttribute="trailing" id="kZ0-HK-x0Z"/>
                            <constraint firstItem="KWt-KV-A2D" firstAttribute="leading" secondItem="8bC-Xf-vdC" secondAttribute="leading" id="zQM-Za-bkN"/>
                        </constraints>
                    </view>
                    <connections>
                        <outlet property="collectionView" destination="KWt-KV-A2D" id="SR1-Cn-p5v"/>
                    </connections>
                </viewController>
                <placeholder placeholderIdentifier="IBFirstResponder" id="dkx-z0-nzr" sceneMemberID="firstResponder"/>
            </objects>
            <point key="canvasLocation" x="133.59999999999999" y="137.18140929535232"/>
        </scene>
    </scenes>
</document>

结果