Question

如何在表格单元格中向UIImageView添加手势识别器？我想要它，这样如果用户点击单元格中的图像，图像将会改变，数据模型将更新。

我知道这需要在UITableViewController中设置。我的代码当前可以执行命令，如果单元格中的任何位置被轻击，但我希望它只在图像被轻敲时执行，而不是在单元格中的任何位置执行。

我在viewDidLoad

中设置了手势识别器

override func viewDidLoad() {
    super.viewDidLoad()

    // Load sample data
    loadSampleHabits()

    // Initialize tap gesture recognizer
    var recognizer = UITapGestureRecognizer(target: self, action: #selector(tapEdit(recognizer:)))
    // Add gesture recognizer to the view
    self.tableView.addGestureRecognizer(recognizer)

这就是功能

//action method for gesture recognizer
func tapEdit(recognizer: UITapGestureRecognizer) {
    if recognizer.state == UIGestureRecognizerState.ended {
        let tapLocation = recognizer.location(in: self.tableView)
        if let tapIndexPath = self.tableView.indexPathForRow(at: tapLocation) {
            if let tappedCell = self.tableView.cellForRow(at: tapIndexPath) as? HabitTableViewCell {
                print("Row Selected")

            }
        }
    }

What the cell looks like

作为次要问题，如果我想在单元格中添加手势识别器和单元格中的图像视图，是否存在任何冲突？

Answer 1

您正在根据需要在tableview上添加手势识别器而不是imageView。哟需要将您的代码从viewDidLoad移动到cellForRowAtIndexPath，并在配置您的单元格时向每个单元格中的imageView添加手势。

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell{
     var recognizer = UITapGestureRecognizer(target: self, action: #selector(tapEdit(recognizer:)))
     // Add gesture recognizer to your image view
     cell.yourimageview.addGestureRecognizer(recognizer)
}

注意：请确保启用图片视图的userinteraction

cell.yourimageview.userInteractionEnabled = YES;

根据您的要求，我建议使用UILongPressGestureRecognizer，因为它在手势和选择中的冲突机会较少。你可以在viewDidLoad中添加UILongPressGestureRecognizer，并根据你的要求访问它。

let lpgr = UILongPressGestureRecognizer(target: self, action: #selector(ViewController.handleLongPress(_:)))
lpgr.minimumPressDuration = 1
tableView.addGestureRecognizer(lpgr)

将方法定义为

func handleLongPress(_ gesture: UILongPressGestureRecognizer){
if gesture.state != .began { return }
let tapLocation = gesture.location(in: self.tableView)
    if let tapIndexPath = self.tableView.indexPathForRow(at: tapLocation) {
        if let tappedCell = self.tableView.cellForRow(at: tapIndexPath) as? HabitTableViewCell {
            print("Row Selected")

        }
}

您可以尝试从方法中删除if recognizer.state == UIGestureRecognizerState.ended条件。

UITapGestureRecognizer是一个离散手势，因此，只有在识别手势时才会调用一次事件处理程序。您根本不需要检查状态。当然，你不会收到.Began州的电话。有关更多信息，请考虑@Rob ans here。

Answer 2

在索引路径

的行的单元格中添加此行

     var recognizer = UITapGestureRecognizer(target: self, action: #selector(tapEdit(recognizer:)))
        // Add gesture recognizer to the view
        cell.yourimageviewname.addGestureRecognizer(recognizer)

cell.yourimageviewname.userInteractionEnabled = true;

Answer 3

我已经设计了这样的解决方案。我只想写下面的示例代码：

import UIKit

protocol CellImageTapDelegate {
    func tableCell(didClickedImageOf tableCell: UITableViewCell)
}

class SampleCell : UITableViewCell {

    var delegate : CellImageTapDelegate?
    var tapGestureRecognizer = UITapGestureRecognizer()

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        initialize()
    }

    private func initialize() {
        tapGestureRecognizer.addTarget(self, action: #selector(SampleCell.imageTapped(gestureRecgonizer:)))
        self.addGestureRecognizer(tapGestureRecognizer)
    }

    func imageTapped(gestureRecgonizer: UITapGestureRecognizer) {
        delegate?.tableCell(didClickedImageOf: self)
    }
}

class ViewController: UITableViewController, CellImageTapDelegate {

    // CellImageTapDelegate
    func tableCell(didClickedImageOf tableCell: UITableViewCell) {
        if let rowIndexPath = tableView.indexPath(for: tableCell) {
            print("Row Selected of indexPath: \(rowIndexPath)")
        }
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 10
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "SampleCellID", for: indexPath) as! SampleCell
        cell.delegate = self
        return cell
    }
}

记得在故事板中做以下事情 1.启用imageview的用户交互 2.设置tableviewcell的类 3.设置tableviewcell的重用标识符

Answer 4

// create an instance of UITapGestureRecognizer and tell it to run 
// an action we'll call "handleTap:"
let tap = UITapGestureRecognizer(target: self, action: Selector("handleTap:"))
// we use our delegate
tap.delegate = self
// allow for user interaction
cell.imageViewName.userInteractionEnabled = true
// add tap as a gestureRecognizer to tapView
cell.imageViewName.addGestureRecognizer(tap)

Answer 5

对于我的建议，你必须在单元格中使用UIButton以获得性能改进，

UIButtons

专为此而设计，并经过Apple的广泛优化。

如果你想要单元格中的图像，你可以使用UIButton里面的图像。

Answer 6

import UIKit

class UserInfoCell: UITableViewCell{

    @IBOutlet weak var imagePlaceholder: UIImageView!
}

class ViewController: UIViewController,UITableViewDelegate,UITableViewDataSource,UIImagePickerControllerDelegate,UINavigationControllerDelegate {

    @IBOutlet weak var tableView: UITableView!


    let imagePicker = UIImagePickerController()
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
            return 1


    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

            let cell = tableView.dequeueReusableCell(withIdentifier: "UserInfoCell" ,for: indexPath ) as! UserInfoCell
            let recognizer = UITapGestureRecognizer(target: self, action: #selector(self.openGallery))

            cell.imagePlaceholder.addGestureRecognizer(recognizer)
            recognizer.numberOfTapsRequired = 1
            cell.imagePlaceholder.isUserInteractionEnabled = true
            cell.name.text = "Akshay"

            if let data = UserDefaults.standard.data(forKey: "savedImage") {
                cell.imagePlaceholder.image = UIImage(data: data as Data)
            }

            return cell




    }
    @objc func openGallery(){
        imagePicker.sourceType = .photoLibrary
        present(imagePicker,animated:  true, completion: nil)
    }
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

        let userimage = info[UIImagePickerController.InfoKey.originalImage] as! UIImage
        let imageData = userimage.jpegData(compressionQuality: 1)!
        UserDefaults.standard.setValue(imageData, forKey: "savedImage")
        print("image found")
        self.imagePicker.dismiss(animated: true, completion: nil)

        self.tableView.reloadData()
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        imagePicker.delegate = self
tableView.tableFooterView = UIView()

    }
}

此代码使用TableViewCell内部的ImageView的Tapgesture从画廊中选择图像

将手势识别器添加到表格单元格中的图像视图

6 个答案: