[英]How to change a label in only one table view cell and save it with Swift?
[英]Swift: Table View is only returning one cell
我正在尝试使用两个不同的原型单元加载表格视图。 profileCell
应该只加载一次并在表格视图的顶部。 dogCell
应该计算从dogCell
下载的名为dogs
的dog
对象数组。 当前,只有第一个单元格显示正确。
我认为numberOfRowsInSection
方法不能准确地计算dogs数组中的dog对象。 当我在return dogs.count + 1
和po dogs.count
上设置断点时,调试器将继续输出0
。
当我使用return dogs.count
,表视图将加载,但仅包含配置文件单元格。 如果我使用return dogs.count + 1
(以说明顶部的配置文件单元格),则在构造dogCell
时会引发异常:“致命错误:索引超出范围”
也许我需要更改tableview重新加载数据的方式?
这是我的代码:
class DogTableViewController: UITableViewController {
var user = User()
let profileCell = ProfileTableViewCell()
var dogs = [Dog]()
override func viewDidLoad() {
super.viewDidLoad()
let userDogRef = Database.database().reference().child("users").child(user.uid!).child("dogs")
let userProfileImageView = UIImageView()
userProfileImageView.translatesAutoresizingMaskIntoConstraints = false
userProfileImageView.widthAnchor.constraint(equalToConstant: 40).isActive = true
userProfileImageView.heightAnchor.constraint(equalToConstant: 40).isActive = true
userProfileImageView.layer.cornerRadius = 20
userProfileImageView.clipsToBounds = true
userProfileImageView.contentMode = .scaleAspectFill
userProfileImageView.image = UIImage(named: "AppIcon")
navigationItem.titleView = userProfileImageView
//MARK: Download dogs from firebase
userDogRef.observe(.childAdded, with: { (snapshot) in
if snapshot.value == nil {
print("no new dog found")
} else {
print("new dog found")
let snapshotValue = snapshot.value as! Dictionary<String, String>
let dogID = snapshotValue["dogID"]!
let dogRef = Database.database().reference().child("dogs").child(dogID)
dogRef.observeSingleEvent(of: .value, with: { (snap) in
print("Found dog data!")
let value = snap.value as? NSDictionary
let newDog = Dog()
newDog.name = value?["name"] as? String ?? ""
newDog.breed = value?["breed"] as? String ?? ""
newDog.creator = value?["creator"] as? String ?? ""
newDog.score = Int(value?["score"] as? String ?? "")
newDog.imageURL = value?["imageURL"] as? String ?? ""
newDog.dogID = snapshot.key
URLSession.shared.dataTask(with: URL(string: newDog.imageURL!)!, completionHandler: { (data, response, error) in
if error != nil {
print(error!)
return
}
newDog.picture = UIImage(data: data!)!
self.dogs.append(newDog)
DispatchQueue.main.async {
self.tableView.reloadData()
}
}).resume()
})
}
})
tableView.estimatedRowHeight = 454
}
// MARK: - Table view data source
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return dogs.count + 1
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row == 0 {
let profileCell = tableView.dequeueReusableCell(withIdentifier: "profileCell", for: indexPath) as! ProfileTableViewCell
profileCell.nameLabel.text = user.name
profileCell.totalReputationLabel.text = String(describing: user.reputation!)
profileCell.usernameLabel.text = user.username
return profileCell
} else {
let dogCell = tableView.dequeueReusableCell(withIdentifier: "dogCell", for: indexPath) as! DogTableViewCell
dogCell.dogBreedLabel.text = dogs[indexPath.row].breed
dogCell.dogNameLabel.text = dogs[indexPath.row].name
dogCell.dogScoreLabel.text = String(describing: dogs[indexPath.row].score)
dogCell.dogImageView.image = dogs[indexPath.row].picture
dogCell.dogCreatorButton.titleLabel?.text = dogs[indexPath.row].creator
dogCell.dogVotesLabel.text = "0"
return dogCell
}
}
}
在写完这个问题后不久,我实际上找到了解决方案,但是我认为这可能对其他人有帮助。
因为第一个indexPath.row专用于配置文件单元,所以我不应该一直使用indexPath.row来导航我的dogs数组。 相反,我应该一直使用indexPath.row - 1
来获取正确的dogs索引。
这是我更新的部分:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row == 0 {
let profileCell = tableView.dequeueReusableCell(withIdentifier: "profileCell", for: indexPath) as! ProfileTableViewCell
profileCell.nameLabel.text = user.name
profileCell.totalReputationLabel.text = String(describing: user.reputation!)
profileCell.usernameLabel.text = user.username
return profileCell
} else {
let dogCell = tableView.dequeueReusableCell(withIdentifier: "dogCell", for: indexPath) as! DogTableViewCell
dogCell.dogBreedLabel.text = dogs[indexPath.row - 1].breed
dogCell.dogNameLabel.text = dogs[indexPath.row - 1].name
dogCell.dogScoreLabel.text = String(describing: dogs[indexPath.row - 1].score)
dogCell.dogImageView.image = dogs[indexPath.row - 1].picture
dogCell.dogCreatorButton.titleLabel?.text = dogs[indexPath.row - 1].creator
dogCell.dogVotesLabel.text = "0"
return dogCell
}
}
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