Question

我目前在单元格中有一张图片，三张UILabel和一个TextView，并希望在单独的视图控制器中使用该数据。视图控制器当前通过push segue连接到单元，我该怎么做呢？

我有这个，但它不起作用：

let uid = FIRAuth.auth()?.currentUser?.uid
    FIRDatabase.database().reference().child("users").child(uid!).observeSingleEvent(of: .value, with: { (snapshot) in
        if let dictionary = snapshot.value as? [String: AnyObject] {
            self.userLabel.text = dictionary["username"] as? String
        }
    })

Answer 1

将一个类型为Dictionary的存储变量添加到源VC和目标VC：var userdata：Dictionary！或者你可以初始化一个空字典让userdata = String：Any

然后，在将快照转换为字典后，将源VC用户数据设置为字典数据并执行segue

if let dictionary = snapshot.value as? [String: AnyObject] {
    self.userLabel.text = dictionary["username"] as? String
    self.userdata = dictionary
    self.performSegue(withIdentifier: "<segueIDHere>", sender: self)
}

然后在源VC中实现VC准备segue方法传递数据：

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "<segueIDHere>" {
        let destinationVC = segue.destination as! <ClassNameofVCHere>
        destinationVC.userdata = self.userdata 
    } 
}

Answer 2

我实际上能找到一种方法来做到这一点。实际上很简单

prepareForSegue

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "showDetails" {
        if let indexPath = self.postsTableView.indexPathForSelectedRow {
            let post = posts[indexPath.row] as! [String: AnyObject]
            let postDetails = post["postID"] as? String
            let controller = segue.destination as! PostDetailsViewController
            controller.postDetails = postDetails
        }
    }
}

PostDetailsViewController

var postDetails: String?

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.

    FIRDatabase.database().reference().child("posts").child(postDetails!).observeSingleEvent(of: .value, with: { (snapshot) in
        if let dictionary = snapshot.value as? [String: AnyObject] {
            self.idLabel.text = dictionary["postID"] as? String
        }
    })
}

从视图控制器中的单元访问Firebase数据

2 个答案: