我使用firebase制作iOS应用。我想检索数据库中的所有用户，并在表格视图中显示他们的名字和个人资料图片。这是我的TableViewCell的代码：
import UIKit
import FirebaseDatabase
import FirebaseAuth
import SDWebImage
class HomeTableViewCell: UITableViewCell {
@IBOutlet weak var nameLabel: UILabel!
@IBOutlet weak var profileImageView: UIImageView!
@IBOutlet weak var likeImageView: UIImageView!
@IBOutlet weak var messageImageView: UIImageView!
@IBOutlet weak var likeCountButton: UIButton!
var homeVC: HomeViewController?
var postReference: DatabaseReference!
var post: UserFile?{
didSet {
updateView()
}
}
var user: UserFile? {
didSet {
updateUserInfo()
}
}
override func awakeFromNib() {
super.awakeFromNib()
nameLabel.text = ""
let berryTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleLikeTap))
likeImageView.addGestureRecognizer(berryTapGesture)
likeImageView.isUserInteractionEnabled = true
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
}
func updateView() {
if let photoURL = post?.picURL {
profileImageView.sd_setImage(with: URL(string: photoURL))
}
API.Post.REF_POSTS.child(post!.id!).observeSingleEvent(of: .value, with: { postSnapshot in
if let postDictionary = postSnapshot.value as? [String:Any] {
let post = UserFile.transformPost(postDictionary: postDictionary, key: postSnapshot.key)
self.updateLike(post: post)
}
})
API.Post.REF_POSTS.child(post!.id!).observe(.childChanged, with: { snapshot in
if let value = snapshot.value as? Int {
self.likeCountButton.setTitle("\(value) berries", for: .normal)
}
})
}
func updateLike(post: UserFile) {
let imageName = post.berries == nil || !post.isBerried! ? "berry" : "berrySelected"
likeImageView.image = UIImage(named: imageName)
// display a message for berries
guard let count = post.berryCount else {
return
}
if count != 0 {
likeCountButton.setTitle("\(count) berries", for: .normal)
} else if post.berryCount == 0 {
likeCountButton.setTitle("Be the first to Like this", for: .normal)
}
}
func incrementberries(forReference ref: DatabaseReference) {
ref.runTransactionBlock({ (currentData: MutableData) -> TransactionResult in
if var post = currentData.value as? [String : AnyObject], let uid = Auth.auth().currentUser?.uid {
var berries: Dictionary<String, Bool>
berries = post["berries"] as? [String : Bool] ?? [:]
var likeCount = post["berryCount"] as? Int ?? 0
if let _ = berries[uid] {
// Unlike the post and remove self from stars
likeCount -= 1
berries.removeValue(forKey: uid)
} else {
// Like the post and add self to stars
likeCount += 1
berries[uid] = true
}
post["berryCount"] = likeCount as AnyObject?
post["berries"] = berries as AnyObject?
currentData.value = post
return TransactionResult.success(withValue: currentData)
}
return TransactionResult.success(withValue: currentData)
}) { (error, committed, snapshot) in
if let error = error {
print(error.localizedDescription)
}
if let postDictionary = snapshot?.value as? [String:Any] {
let post = UserFile.transformPost(postDictionary: postDictionary, key: snapshot!.key)
self.updateLike(post: post)
}
}
}
func handleLikeTap() {
postReference = API.Post.REF_POSTS.child(post!.id!)
incrementberries(forReference: postReference)
}
override func prepareForReuse() {
super.prepareForReuse()
profileImageView.image = UIImage(named: "industribune-default-no-profile-pic")
}
func updateUserInfo() {
nameLabel.text = user?.username
if let photoURL = user?.profileImageURL {
profileImageView.sd_setImage(with: URL(string: photoURL), placeholderImage: UIImage(named: "industribune-default-no-profile-pic"))
}
}
}
我在HomeViewController上显示此单元格：
import UIKit
import FirebaseAuth
import FirebaseDatabase
import FirebaseStorage
import Firebase
class HomeViewController: UIViewController {
@IBOutlet weak var tableView: UITableView!
@IBOutlet weak var activityIndicatorView: UIActivityIndicatorView!
var posts = [UserFile]()
var users = [UserFile]()
override func viewDidLoad() {
super.viewDidLoad()
// for performance set an estimated row height
tableView.estimatedRowHeight = 1
// but also request to dynamically adjust to content using AutoLayout
tableView.rowHeight = UITableViewAutomaticDimension
//tableView.delegate = self
tableView.dataSource = self
loadPosts()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func loadPosts() {
activityIndicatorView.startAnimating()
API.User.observePosts { (newPost) in
guard let userID = newPost.uid else { return }
self.fetchUser(uid: userID, completed: {
// append the new Post and Reload after the user
// has been cached
self.posts.append(newPost)
self.activityIndicatorView.stopAnimating()
self.tableView.reloadData()
})
}
}
func fetchUser(uid: String, completed: @escaping () -> Void) {
API.User.observeUser(withID: uid) { user in
self.users.append(user)
completed()
}
}
}
extension HomeViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return posts.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "HomeTableViewCell", for: indexPath) as! HomeTableViewCell
cell.post = posts[indexPath.row]
cell.user = users[indexPath.row]
cell.homeVC = self
return cell
}
}
我的项目中有很多疯狂，所以如果您有任何问题以及我做错了，请告诉我。如果它太复杂而无法理解我已准备好擦除所有内容并重新开始。
我诚实地认为我遵循了所有指导方针来提出问题，所以不要把这个问题关闭或者其他什么。
答案 0 :(得分：1)
这是很多代码。试试这个超级减少的例子。为此，users节点仅将名称存储为子节点，但也可以包含图像，电子邮件，地址等。
示例用户节点
users
uid_0:
name: "Bert"
uid_1:
name: "Ernie"
和一些代码
var usersArray = [ [String: Any] ]() //an array of dictionaries.
class ViewController: UIViewController {
//set up firebase references here
override func viewDidLoad() {
super.viewDidLoad()
let usersRef = self.ref.child("users")
usersRef.observeSingleEvent(of: .value, with: { snapshot in
for child in snapshot.children {
let snap = child as! DataSnapshot
let userDict = snap.value as! [String: Any]
self.usersArray.append(userDict)
}
self.tableView.reloadData()
})
和tableView委托方法
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.usersArray.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "HomeTableViewCell", for: indexPath) as! HomeTableViewCell
let userDict = self.usersArray[indexPath.row]
cell.text = userDict["name"] as! String
//cell.imge = userDict["image"] etc etc
return cell
}
现在......说的都是。这是一个UserClass对象数组的完美用法，而不是字典。
这是一个起点......
class UserClass {
var name = ""
var image = ""
func init(snap: DataSnapshot) {
//populate the vars from the snapshot
}
}
var userClassArray = [UserClass]()
请勿复制并粘贴此内容，因为可能存在拼写错误，但它应该指向正确的方向。