ios - 调用另一个 Swift 类中的函数

Question

我需要调用这个函数。我需要接收用户identityString。我怎样才能做到这一点？

class GeneralChatroom: UIViewController, 
                       UITableViewDataSource, 
                       UITableViewDelegate, 
                       UITextFieldDelegate, 
                       UITextViewDelegate {

    //Get Data of current cell that has been tapped
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {    
        let userIdentityString = generalRoomDataArr[indexPath.row].cellUserId

        print("Uid of cell Data: " + userIdentityString!)
        print("section: \(indexPath.section)")
        print("row: \(indexPath.row)")
    }

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


    let cell = tableView.dequeueReusableCell(withIdentifier: "cell")

    //Transform Data From ^ to load at the bottom
    tableView.transform = CGAffineTransform (scaleX: 1,y: -1);
    cell?.contentView.transform = CGAffineTransform (scaleX: 1,y: -1);
    cell?.accessoryView?.transform = CGAffineTransform (scaleX: 1,y: -1);

    //Set username label to display username
    let usernameLabel = cell?.viewWithTag(1) as! UILabel
    usernameLabel.text = generalRoomDataArr[indexPath.row].username

    //Set mesage TextView Label to display message in textView
    let messageLabel = cell?.viewWithTag(5) as! UITextView
    messageLabel.text = generalRoomDataArr[indexPath.row].message

    //TO DO: dont know if this actually works prob can delete
    messageLabel.setContentOffset(CGPoint(x: 0, y: 0), animated: false)


    //initialize UI Profile Image
    let imageView = cell?.viewWithTag(3) as! UIImageView

    //Make Porfile Image Cirlce
    imageView.layer.cornerRadius = imageView.frame.size.width/2
    imageView.clipsToBounds = true

    //Set timeStampLabel to current time AGO
    let timeStampLabel = cell?.viewWithTag(4) as! UILabel
    timeStampLabel.text = generalRoomDataArr[indexPath.row].timeStamp
    timeStampLabel.numberOfLines = 0


    //Loading and change of Usesrs profile image on chat cell
    let userProfileChatImage = generalRoomDataArr[indexPath.row].photoURL

    //Load profile image(on cell) with URL & Alamofire Library
        let downloadURL = NSURL(string: userProfileChatImage!)
        imageView.af_setImage(withURL: downloadURL as! URL)

    return cell!
}

}

但是我需要在不同的类中调用该函数来获取userIdentityString。我怎样才能做到这一点？我需要在“图像点击”函数中调用它。

class GeneralChatroomTableViewCell: UITableViewCell {

    @IBOutlet weak var profileImageView: UIImageView!
    @IBOutlet weak var textViewHeight: NSLayoutConstraint!

    override func awakeFromNib() {
        super.awakeFromNib()

        // You must to use interaction enabled
        profileImageView.isUserInteractionEnabled = true
        profileImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(imageTapped(_:))))
    }

    func imageTapped(_ sender: UITapGestureRecognizer) {
        //first you need to call the function that reads the cell. Recieve the UID
        print("image tapped")
    }
}

也许这样会更清楚

func imageTapped(_ sender: UITapGestureRecognizer) {

        let userIDString = GeneralChatroom.tableView(userIdentityString: userIdentityString)

        print(userIDString)

        //first you need to call the function that reads the cell. Recieve the UID
        print("image tapped")


    }



func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) -> String{

        let userIdentityString = generalRoomDataArr[indexPath.row].cellUserId

        print("Uid of cell Data: " + userIdentityString!)
        print("section: \(indexPath.section)")
        print("row: \(indexPath.row)")

        //1.) If imageView touch is deteected
        //2.) Segua to new view controller by passing in the string UID(userIdentityString) of the cell
        //3.) Get database information based on the UID that is added(look at prevous methods)
        //      -might have to call this function and use separeate function
        //4.) Output data from database Users to represent a user profile



        //All you have to do is pass a UID (Check other Database methods to send UID)

        return userIdentityString!

    }

Answer 1

好的，正如我在评论中所说，这个答案不是关于从 swift 类调用另一个函数，因为您正在尝试调用委托(delegate)函数。我不确定是否可以保证如果手动调用该函数将具有预期值。我要做的就是在您的 TableViewCell 上创建一个属性持有userId .

class GeneralChatroomTableViewCell: UITableViewCell {

    @IBOutlet weak var profileImageView: UIImageView!
    @IBOutlet weak var textViewHeight: NSLayoutConstraint!

    // User Id
    var userId: String?

    override func awakeFromNib() {
        super.awakeFromNib()

        // You must to use interaction enabled
        profileImageView.isUserInteractionEnabled = true
        profileImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(imageTapped(_:))))
    }

    func imageTapped(_ sender: UITapGestureRecognizer) {

        //first you need to call the function that reads the cell. Recieve the UID
        print("image tapped")
        if let uid = self.userId {
            // Do whatever you want with userId
        }
    }
}

因此，我在 TableViewCell 上添加了一个可选的 userId 属性。为了填充，我们将在 func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { 中执行此操作。委托(delegate)功能。我不确定你的是什么样子，因为你没有提供该代码，所以我只是继续了解它通常是什么样子以及你的 GeneralChatroomTableViewCell 是什么。

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

    var cell = tableView.dequeueReusableCell(withIdentifier: NSStringFromClass(GeneralChatroomTableViewCell.self), for: indexPath) as! GeneralChatroomTableViewCell
    (cell as! GeneralChatroomTableViewCell).userId = generalRoomDataArr[indexPath.row].cellUserId
    return cell
}

每当创建一个单元格以在表中显示时，就会调用此函数。所以现在在创建单元格时我们设置 userId这样我们就可以在需要时随时使用它。

正如上面的评论中所述，只有在创建单元格时该数据可用时，这才有用。