如何使用 firebase 在 ios 中实现私人聊天
How to implement private chat in ios using firebase
我在我的 ios 应用程序中实现了私人聊天。然而，它并不是那么私密。当我发送一条我打算发送给一个人的消息时，应用程序中的每个人都可以看到它。我在这里使用了三个视图控制器。
FirstViewController 有一个用户列表，当单击单元格时，它会转到 DetailedViewController。在这个viewController中，只列出了被点击的用户的详细信息。接下来，当我按下 DetailedViewController 中的撰写按钮时，目标是转到 MessageUserController。这就是我被困的地方。这是转到 MessageUserController 的代码：
var username: String?
@IBAction func sendMessage(_ sender: Any) {
performSegue(withIdentifier: "sendMessageToUser", sender: self.username)
}
override public func prepare(for segue: UIStoryboardSegue, sender: Any?) {
guard segue.identifier == "sendMessageToUser", let chatVc = segue.destination as? MessageViewController else {
return
}
chatVc.senderId = self.loggedInUser?.uid
chatVc.senderDisplayName = self.username
}
我假设发件人可以是用户名，因为它对用户来说是唯一的。当我点击一个用户聊天时，它工作正常但是当我点击另一个用户时，第一个用户之间的聊天已经显示在新用户的 chatController
在第一个ViewController中，用户名是这样传递的：
if segue.identifier == "UsersProfile" {
if let indexPath = sender as? IndexPath{
let vc = segue.destination as! UsersProfileViewController
let post = self.posts[indexPath.row] as! [String: AnyObject]
let username = post["username"] as? String
vc.username = username
}
}
整个视图控制器：
import UIKit
import Photos
import Firebase
import FirebaseDatabase
import JSQMessagesViewController
class SendMessageViewController: JSQMessagesViewController {
var username: String?
//var receiverData = AnyObject?()
var messages = [JSQMessage]()
private var photoMessageMap = [String: JSQPhotoMediaItem]()
private let imageURLNotSetKey = "NOTSET"
lazy var outgoingBubbleImageView: JSQMessagesBubbleImage = self.setupOutgoingBubble()
lazy var incomingBubbleImageView: JSQMessagesBubbleImage = self.setupIncomingBubble()
var rootRef = FIRDatabase.database().reference()
var messageRef = FIRDatabase.database().reference().child("messages")
private var newMessageRefHandle: FIRDatabaseHandle?
private lazy var usersTypingQuery: FIRDatabaseQuery =
self.rootRef.child("typingIndicator").queryOrderedByValue().queryEqual(toValue: true)
lazy var storageRef: FIRStorageReference = FIRStorage.storage().reference(forURL: "gs://gsignme-14416.appspot.com")
private var updatedMessageRefHandle: FIRDatabaseHandle?
private lazy var userIsTypingRef: FIRDatabaseReference =
self.rootRef.child("typingIndicator").child(self.senderId) // 1
private var localTyping = false // 2
var isTyping: Bool {
get {
return localTyping
}
set {
// 3
localTyping = newValue
userIsTypingRef.setValue(newValue)
}
}
override func viewDidLoad() {
super.viewDidLoad()
self.senderId = FIRAuth.auth()?.currentUser?.uid
// Do any additional setup after loading the view.
self.navigationController?.navigationBar.barTintColor = UIColor(red:0.23, green:0.73, blue:1.00, alpha:1.0)
self.navigationController?.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.white]
self.navigationItem.title = senderDisplayName
self.navigationItem.rightBarButtonItem?.tintColor = UIColor.white
self.navigationItem.leftBarButtonItem?.tintColor = UIColor.white
// No avatars
collectionView!.collectionViewLayout.incomingAvatarViewSize = CGSize.zero
collectionView!.collectionViewLayout.outgoingAvatarViewSize = CGSize.zero
observeMessages()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
observeTyping()
}
deinit {
if let refHandle = newMessageRefHandle {
messageRef.removeObserver(withHandle: refHandle)
}
if let refHandle = updatedMessageRefHandle {
messageRef.removeObserver(withHandle: refHandle)
}
}
override func collectionView(_ collectionView: JSQMessagesCollectionView!, messageDataForItemAt indexPath: IndexPath!) -> JSQMessageData! {
return messages[indexPath.item]
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return messages.count
}
private func setupOutgoingBubble() -> JSQMessagesBubbleImage {
let bubbleImageFactory = JSQMessagesBubbleImageFactory()
return bubbleImageFactory!.outgoingMessagesBubbleImage(with: UIColor.jsq_messageBubbleBlue())
}
private func setupIncomingBubble() -> JSQMessagesBubbleImage {
let bubbleImageFactory = JSQMessagesBubbleImageFactory()
return bubbleImageFactory!.incomingMessagesBubbleImage(with: UIColor.jsq_messageBubbleLightGray())
}
override func collectionView(_ collectionView: JSQMessagesCollectionView!, messageBubbleImageDataForItemAt indexPath: IndexPath!) -> JSQMessageBubbleImageDataSource! {
let message = messages[indexPath.item] // 1
if message.senderId == senderId { // 2
return outgoingBubbleImageView
} else { // 3
return incomingBubbleImageView
}
}
override func collectionView(_ collectionView: JSQMessagesCollectionView!, avatarImageDataForItemAt indexPath: IndexPath!) -> JSQMessageAvatarImageDataSource! {
return nil
}
override func collectionView(_ collectionView: JSQMessagesCollectionView!, layout collectionViewLayout: JSQMessagesCollectionViewFlowLayout!, heightForMessageBubbleTopLabelAt indexPath: IndexPath!) -> CGFloat {
return 15
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = super.collectionView(collectionView, cellForItemAt: indexPath) as! JSQMessagesCollectionViewCell
let message = messages[indexPath.item]
if message.senderId == senderId {
cell.textView?.textColor = UIColor.white
} else {
cell.textView?.textColor = UIColor.black
}
return cell
}
//ADD A NEW MESSAGE
private func addMessage(withId id: String, name: String, text: String) {
if let message = JSQMessage(senderId: id, displayName: name, text: text) {
messages.append(message)
}
}
override func didPressSend(_ button: UIButton!, withMessageText text: String!, senderId: String!, senderDisplayName: String!, date: Date!) {
let itemRef = rootRef.child("messages").childByAutoId() // 1
let messageItem = [ // 2
"senderId": senderId!,
"ReceiverName": senderDisplayName!,
"text": text!,
]
itemRef.setValue(messageItem) // 3
JSQSystemSoundPlayer.jsq_playMessageSentSound() // 4
finishSendingMessage() // 5
isTyping = false
}
private func observeMessages() {
// 1.
let messageQuery = rootRef.child("messages").queryLimited(toLast: 25)
// 2. We can use the observe method to listen for new
// messages being written to the Firebase DB
newMessageRefHandle = messageQuery.observe(.childAdded, with: { (snapshot) -> Void in
// 3
let messageData = snapshot.value as! Dictionary<String, String>
if let id = messageData["senderId"] as String!, let name = messageData["ReceiverName"] as String!, let text = messageData["text"] as String!, text.characters.count > 0 {
// 4
self.addMessage(withId: id, name: name, text: text)
// 5
self.finishReceivingMessage()
} else if let id = messageData["senderId"] as String!,
let photoURL = messageData["photoURL"] as String! { // 1
// 2
if let mediaItem = JSQPhotoMediaItem(maskAsOutgoing: id == self.senderId) {
// 3
self.addPhotoMessage(withId: id, key: snapshot.key, mediaItem: mediaItem)
// 4
if photoURL.hasPrefix("gs://") {
self.fetchImageDataAtURL(photoURL, forMediaItem: mediaItem, clearsPhotoMessageMapOnSuccessForKey: nil)
}
}
} else {
print("Error! Could not decode message data")
}
})
// We can also use the observer method to listen for
// changes to existing messages.
// We use this to be notified when a photo has been stored
// to the Firebase Storage, so we can update the message data
updatedMessageRefHandle = messageRef.observe(.childChanged, with: { (snapshot) in
let key = snapshot.key
let messageData = snapshot.value as! Dictionary<String, String> // 1
if let photoURL = messageData["photoURL"] as String! { // 2
// The photo has been updated.
if let mediaItem = self.photoMessageMap[key] { // 3
self.fetchImageDataAtURL(photoURL, forMediaItem: mediaItem, clearsPhotoMessageMapOnSuccessForKey: key) // 4
}
}
})
}
override func textViewDidChange(_ textView: UITextView) {
super.textViewDidChange(textView)
// If the text is not empty, the user is typing
isTyping = textView.text != ""
}
private func observeTyping() {
let typingIndicatorRef = rootRef.child("typingIndicator")
userIsTypingRef = typingIndicatorRef.child(senderId)
userIsTypingRef.onDisconnectRemoveValue()
usersTypingQuery = typingIndicatorRef.queryOrderedByValue().queryEqual(toValue: true)
// 1
usersTypingQuery.observe(.value) { (data: FIRDataSnapshot) in
// 2 You're the only one typing, don't show the indicator
if data.childrenCount == 1 && self.isTyping {
return
}
// 3 Are there others typing?
self.showTypingIndicator = data.childrenCount > 0
self.scrollToBottom(animated: true)
}
}
func sendPhotoMessage() -> String? {
let itemRef = messageRef.childByAutoId()
let messageItem = [
"photoURL": imageURLNotSetKey,
"senderId": senderId!,
]
itemRef.setValue(messageItem)
JSQSystemSoundPlayer.jsq_playMessageSentSound()
finishSendingMessage()
return itemRef.key
}
func setImageURL(_ url: String, forPhotoMessageWithKey key: String) {
let itemRef = messageRef.child(key)
itemRef.updateChildValues(["photoURL": url])
}
override func didPressAccessoryButton(_ sender: UIButton) {
let picker = UIImagePickerController()
picker.delegate = self as! UIImagePickerControllerDelegate & UINavigationControllerDelegate
if (UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.camera)) {
picker.sourceType = UIImagePickerControllerSourceType.camera
} else {
picker.sourceType = UIImagePickerControllerSourceType.photoLibrary
}
present(picker, animated: true, completion:nil)
}
private func addPhotoMessage(withId id: String, key: String, mediaItem: JSQPhotoMediaItem) {
if let message = JSQMessage(senderId: id, displayName: "", media: mediaItem) {
messages.append(message)
if (mediaItem.image == nil) {
photoMessageMap[key] = mediaItem
}
collectionView.reloadData()
}
}
private func fetchImageDataAtURL(_ photoURL: String, forMediaItem mediaItem: JSQPhotoMediaItem, clearsPhotoMessageMapOnSuccessForKey key: String?) {
// 1
let storageRef = FIRStorage.storage().reference(forURL: photoURL)
// 2
storageRef.data(withMaxSize: INT64_MAX){ (data, error) in
if let error = error {
print("Error downloading image data: \(error)")
return
}
// 3
storageRef.metadata(completion: { (metadata, metadataErr) in
if let error = metadataErr {
print("Error downloading metadata: \(error)")
return
}
// 4
if (metadata?.contentType == "image") {
mediaItem.image = UIImage.init(data: data!)
} else {
mediaItem.image = UIImage.init(data: data!)
}
self.collectionView.reloadData()
// 5
guard key != nil else {
return
}
self.photoMessageMap.removeValue(forKey: key!)
})
}
}
}
extension SendMessageViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
func imagePickerController(_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [String : Any]) {
picker.dismiss(animated: true, completion:nil)
// 1
if let photoReferenceUrl = info[UIImagePickerControllerReferenceURL] as? URL {
// Handle picking a Photo from the Photo Library
// 2
let assets = PHAsset.fetchAssets(withALAssetURLs: [photoReferenceUrl], options: nil)
let asset = assets.firstObject
// 3
if let key = sendPhotoMessage() {
// 4
asset?.requestContentEditingInput(with: nil, completionHandler: { (contentEditingInput, info) in
let imageFileURL = contentEditingInput?.fullSizeImageURL
// 5
let path = "\(FIRAuth.auth()?.currentUser?.uid)/\(Int(Date.timeIntervalSinceReferenceDate * 1000))/\(photoReferenceUrl.lastPathComponent)"
// 6
self.storageRef.child(path).putFile(imageFileURL!, metadata: nil) { (metadata, error) in
if let error = error {
print("Error uploading photo: \(error.localizedDescription)")
return
}
// 7
self.setImageURL(self.storageRef.child((metadata?.path)!).description, forPhotoMessageWithKey: key)
}
})
}
} else {
// Handle picking a Photo from the Camera - TODO
// 1
let image = info[UIImagePickerControllerOriginalImage] as! UIImage
// 2
if let key = sendPhotoMessage() {
// 3
let imageData = UIImageJPEGRepresentation(image, 1.0)
// 4
let imagePath = FIRAuth.auth()!.currentUser!.uid + "/\(Int(Date.timeIntervalSinceReferenceDate * 1000)).jpg"
// 5
let metadata = FIRStorageMetadata()
metadata.contentType = "image/jpeg"
// 6
storageRef.child(imagePath).put(imageData!, metadata: metadata) { (metadata, error) in
if let error = error {
print("Error uploading photo: \(error)")
return
}
// 7
self.setImageURL(self.storageRef.child((metadata?.path)!).description, forPhotoMessageWithKey: key)
}
}
}
}
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
picker.dismiss(animated: true, completion:nil)
}
}
在我看来，这不是您所说的隐私问题，只是您在加载新对话时没有清除消息视图控制器上的数据。
最终这真的取决于你希望它有多安全；如果您很高兴将私人消息保存在内存中，那么在用户注销之前不要销毁它们——您甚至可以将多个私人对话保存在 CoreData 数据库中。这种方式还是比较安全的，方便用户和性能。如果您希望尽快销毁消息，请清除 viewDidDisappear 上的数据，然后检查您的 prepareForSegue 方法以再次清除数据。如果存储强引用不是您想要的，您也可以在每次关闭时销毁整个消息控制器。
这方面的一个例子，作为故事板：
- 应用加载
- 用户 1 已登录
- 用户1选择私信
- User1 与 User2
进行了对话
- User1 切换到与 User3
的对话
[伪代码]
userDidChangeRecipient {
// destroy messages view controller
// or destroy Firebase array data and destroy the reference to the message/conversation ID
}
并且每次加载视图控制器时：
prepareForSegue {
if strongRefToMessagesVC == nil {
// instantiate a new instance of vc from nib or scratch
// load the appropriate message/conversation ID
// load messages
}
}
更多挖掘：
这里有两种可能：
切换消息时并没有破坏视图控制器，本教程希望您这样做。在这种情况下，您需要查看 segue 何时结束或用户关闭消息视图控制器并销毁它或清空数组。
您正在尝试将所有私人消息写入同一个 JSQMessage 数组。我注意到在那个视图控制器中你有：
var messageRef = FIRDatabase.database().reference().child("messages")
这是您正在使用的数据库连接吗？每个私人消息对话都应该有一个唯一的参考 ID，这样它们就不会重叠，否则每个用户都会从 Firebase 加载同一组消息。
我在我的 ios 应用程序中实现了私人聊天。然而，它并不是那么私密。当我发送一条我打算发送给一个人的消息时，应用程序中的每个人都可以看到它。我在这里使用了三个视图控制器。
FirstViewController 有一个用户列表，当单击单元格时，它会转到 DetailedViewController。在这个viewController中，只列出了被点击的用户的详细信息。接下来，当我按下 DetailedViewController 中的撰写按钮时，目标是转到 MessageUserController。这就是我被困的地方。这是转到 MessageUserController 的代码：
var username: String?
@IBAction func sendMessage(_ sender: Any) {
performSegue(withIdentifier: "sendMessageToUser", sender: self.username)
}
override public func prepare(for segue: UIStoryboardSegue, sender: Any?) {
guard segue.identifier == "sendMessageToUser", let chatVc = segue.destination as? MessageViewController else {
return
}
chatVc.senderId = self.loggedInUser?.uid
chatVc.senderDisplayName = self.username
}
我假设发件人可以是用户名，因为它对用户来说是唯一的。当我点击一个用户聊天时，它工作正常但是当我点击另一个用户时，第一个用户之间的聊天已经显示在新用户的 chatController
在第一个ViewController中，用户名是这样传递的：
if segue.identifier == "UsersProfile" {
if let indexPath = sender as? IndexPath{
let vc = segue.destination as! UsersProfileViewController
let post = self.posts[indexPath.row] as! [String: AnyObject]
let username = post["username"] as? String
vc.username = username
}
}
整个视图控制器：
import UIKit
import Photos
import Firebase
import FirebaseDatabase
import JSQMessagesViewController
class SendMessageViewController: JSQMessagesViewController {
var username: String?
//var receiverData = AnyObject?()
var messages = [JSQMessage]()
private var photoMessageMap = [String: JSQPhotoMediaItem]()
private let imageURLNotSetKey = "NOTSET"
lazy var outgoingBubbleImageView: JSQMessagesBubbleImage = self.setupOutgoingBubble()
lazy var incomingBubbleImageView: JSQMessagesBubbleImage = self.setupIncomingBubble()
var rootRef = FIRDatabase.database().reference()
var messageRef = FIRDatabase.database().reference().child("messages")
private var newMessageRefHandle: FIRDatabaseHandle?
private lazy var usersTypingQuery: FIRDatabaseQuery =
self.rootRef.child("typingIndicator").queryOrderedByValue().queryEqual(toValue: true)
lazy var storageRef: FIRStorageReference = FIRStorage.storage().reference(forURL: "gs://gsignme-14416.appspot.com")
private var updatedMessageRefHandle: FIRDatabaseHandle?
private lazy var userIsTypingRef: FIRDatabaseReference =
self.rootRef.child("typingIndicator").child(self.senderId) // 1
private var localTyping = false // 2
var isTyping: Bool {
get {
return localTyping
}
set {
// 3
localTyping = newValue
userIsTypingRef.setValue(newValue)
}
}
override func viewDidLoad() {
super.viewDidLoad()
self.senderId = FIRAuth.auth()?.currentUser?.uid
// Do any additional setup after loading the view.
self.navigationController?.navigationBar.barTintColor = UIColor(red:0.23, green:0.73, blue:1.00, alpha:1.0)
self.navigationController?.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.white]
self.navigationItem.title = senderDisplayName
self.navigationItem.rightBarButtonItem?.tintColor = UIColor.white
self.navigationItem.leftBarButtonItem?.tintColor = UIColor.white
// No avatars
collectionView!.collectionViewLayout.incomingAvatarViewSize = CGSize.zero
collectionView!.collectionViewLayout.outgoingAvatarViewSize = CGSize.zero
observeMessages()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
observeTyping()
}
deinit {
if let refHandle = newMessageRefHandle {
messageRef.removeObserver(withHandle: refHandle)
}
if let refHandle = updatedMessageRefHandle {
messageRef.removeObserver(withHandle: refHandle)
}
}
override func collectionView(_ collectionView: JSQMessagesCollectionView!, messageDataForItemAt indexPath: IndexPath!) -> JSQMessageData! {
return messages[indexPath.item]
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return messages.count
}
private func setupOutgoingBubble() -> JSQMessagesBubbleImage {
let bubbleImageFactory = JSQMessagesBubbleImageFactory()
return bubbleImageFactory!.outgoingMessagesBubbleImage(with: UIColor.jsq_messageBubbleBlue())
}
private func setupIncomingBubble() -> JSQMessagesBubbleImage {
let bubbleImageFactory = JSQMessagesBubbleImageFactory()
return bubbleImageFactory!.incomingMessagesBubbleImage(with: UIColor.jsq_messageBubbleLightGray())
}
override func collectionView(_ collectionView: JSQMessagesCollectionView!, messageBubbleImageDataForItemAt indexPath: IndexPath!) -> JSQMessageBubbleImageDataSource! {
let message = messages[indexPath.item] // 1
if message.senderId == senderId { // 2
return outgoingBubbleImageView
} else { // 3
return incomingBubbleImageView
}
}
override func collectionView(_ collectionView: JSQMessagesCollectionView!, avatarImageDataForItemAt indexPath: IndexPath!) -> JSQMessageAvatarImageDataSource! {
return nil
}
override func collectionView(_ collectionView: JSQMessagesCollectionView!, layout collectionViewLayout: JSQMessagesCollectionViewFlowLayout!, heightForMessageBubbleTopLabelAt indexPath: IndexPath!) -> CGFloat {
return 15
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = super.collectionView(collectionView, cellForItemAt: indexPath) as! JSQMessagesCollectionViewCell
let message = messages[indexPath.item]
if message.senderId == senderId {
cell.textView?.textColor = UIColor.white
} else {
cell.textView?.textColor = UIColor.black
}
return cell
}
//ADD A NEW MESSAGE
private func addMessage(withId id: String, name: String, text: String) {
if let message = JSQMessage(senderId: id, displayName: name, text: text) {
messages.append(message)
}
}
override func didPressSend(_ button: UIButton!, withMessageText text: String!, senderId: String!, senderDisplayName: String!, date: Date!) {
let itemRef = rootRef.child("messages").childByAutoId() // 1
let messageItem = [ // 2
"senderId": senderId!,
"ReceiverName": senderDisplayName!,
"text": text!,
]
itemRef.setValue(messageItem) // 3
JSQSystemSoundPlayer.jsq_playMessageSentSound() // 4
finishSendingMessage() // 5
isTyping = false
}
private func observeMessages() {
// 1.
let messageQuery = rootRef.child("messages").queryLimited(toLast: 25)
// 2. We can use the observe method to listen for new
// messages being written to the Firebase DB
newMessageRefHandle = messageQuery.observe(.childAdded, with: { (snapshot) -> Void in
// 3
let messageData = snapshot.value as! Dictionary<String, String>
if let id = messageData["senderId"] as String!, let name = messageData["ReceiverName"] as String!, let text = messageData["text"] as String!, text.characters.count > 0 {
// 4
self.addMessage(withId: id, name: name, text: text)
// 5
self.finishReceivingMessage()
} else if let id = messageData["senderId"] as String!,
let photoURL = messageData["photoURL"] as String! { // 1
// 2
if let mediaItem = JSQPhotoMediaItem(maskAsOutgoing: id == self.senderId) {
// 3
self.addPhotoMessage(withId: id, key: snapshot.key, mediaItem: mediaItem)
// 4
if photoURL.hasPrefix("gs://") {
self.fetchImageDataAtURL(photoURL, forMediaItem: mediaItem, clearsPhotoMessageMapOnSuccessForKey: nil)
}
}
} else {
print("Error! Could not decode message data")
}
})
// We can also use the observer method to listen for
// changes to existing messages.
// We use this to be notified when a photo has been stored
// to the Firebase Storage, so we can update the message data
updatedMessageRefHandle = messageRef.observe(.childChanged, with: { (snapshot) in
let key = snapshot.key
let messageData = snapshot.value as! Dictionary<String, String> // 1
if let photoURL = messageData["photoURL"] as String! { // 2
// The photo has been updated.
if let mediaItem = self.photoMessageMap[key] { // 3
self.fetchImageDataAtURL(photoURL, forMediaItem: mediaItem, clearsPhotoMessageMapOnSuccessForKey: key) // 4
}
}
})
}
override func textViewDidChange(_ textView: UITextView) {
super.textViewDidChange(textView)
// If the text is not empty, the user is typing
isTyping = textView.text != ""
}
private func observeTyping() {
let typingIndicatorRef = rootRef.child("typingIndicator")
userIsTypingRef = typingIndicatorRef.child(senderId)
userIsTypingRef.onDisconnectRemoveValue()
usersTypingQuery = typingIndicatorRef.queryOrderedByValue().queryEqual(toValue: true)
// 1
usersTypingQuery.observe(.value) { (data: FIRDataSnapshot) in
// 2 You're the only one typing, don't show the indicator
if data.childrenCount == 1 && self.isTyping {
return
}
// 3 Are there others typing?
self.showTypingIndicator = data.childrenCount > 0
self.scrollToBottom(animated: true)
}
}
func sendPhotoMessage() -> String? {
let itemRef = messageRef.childByAutoId()
let messageItem = [
"photoURL": imageURLNotSetKey,
"senderId": senderId!,
]
itemRef.setValue(messageItem)
JSQSystemSoundPlayer.jsq_playMessageSentSound()
finishSendingMessage()
return itemRef.key
}
func setImageURL(_ url: String, forPhotoMessageWithKey key: String) {
let itemRef = messageRef.child(key)
itemRef.updateChildValues(["photoURL": url])
}
override func didPressAccessoryButton(_ sender: UIButton) {
let picker = UIImagePickerController()
picker.delegate = self as! UIImagePickerControllerDelegate & UINavigationControllerDelegate
if (UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.camera)) {
picker.sourceType = UIImagePickerControllerSourceType.camera
} else {
picker.sourceType = UIImagePickerControllerSourceType.photoLibrary
}
present(picker, animated: true, completion:nil)
}
private func addPhotoMessage(withId id: String, key: String, mediaItem: JSQPhotoMediaItem) {
if let message = JSQMessage(senderId: id, displayName: "", media: mediaItem) {
messages.append(message)
if (mediaItem.image == nil) {
photoMessageMap[key] = mediaItem
}
collectionView.reloadData()
}
}
private func fetchImageDataAtURL(_ photoURL: String, forMediaItem mediaItem: JSQPhotoMediaItem, clearsPhotoMessageMapOnSuccessForKey key: String?) {
// 1
let storageRef = FIRStorage.storage().reference(forURL: photoURL)
// 2
storageRef.data(withMaxSize: INT64_MAX){ (data, error) in
if let error = error {
print("Error downloading image data: \(error)")
return
}
// 3
storageRef.metadata(completion: { (metadata, metadataErr) in
if let error = metadataErr {
print("Error downloading metadata: \(error)")
return
}
// 4
if (metadata?.contentType == "image") {
mediaItem.image = UIImage.init(data: data!)
} else {
mediaItem.image = UIImage.init(data: data!)
}
self.collectionView.reloadData()
// 5
guard key != nil else {
return
}
self.photoMessageMap.removeValue(forKey: key!)
})
}
}
}
extension SendMessageViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
func imagePickerController(_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [String : Any]) {
picker.dismiss(animated: true, completion:nil)
// 1
if let photoReferenceUrl = info[UIImagePickerControllerReferenceURL] as? URL {
// Handle picking a Photo from the Photo Library
// 2
let assets = PHAsset.fetchAssets(withALAssetURLs: [photoReferenceUrl], options: nil)
let asset = assets.firstObject
// 3
if let key = sendPhotoMessage() {
// 4
asset?.requestContentEditingInput(with: nil, completionHandler: { (contentEditingInput, info) in
let imageFileURL = contentEditingInput?.fullSizeImageURL
// 5
let path = "\(FIRAuth.auth()?.currentUser?.uid)/\(Int(Date.timeIntervalSinceReferenceDate * 1000))/\(photoReferenceUrl.lastPathComponent)"
// 6
self.storageRef.child(path).putFile(imageFileURL!, metadata: nil) { (metadata, error) in
if let error = error {
print("Error uploading photo: \(error.localizedDescription)")
return
}
// 7
self.setImageURL(self.storageRef.child((metadata?.path)!).description, forPhotoMessageWithKey: key)
}
})
}
} else {
// Handle picking a Photo from the Camera - TODO
// 1
let image = info[UIImagePickerControllerOriginalImage] as! UIImage
// 2
if let key = sendPhotoMessage() {
// 3
let imageData = UIImageJPEGRepresentation(image, 1.0)
// 4
let imagePath = FIRAuth.auth()!.currentUser!.uid + "/\(Int(Date.timeIntervalSinceReferenceDate * 1000)).jpg"
// 5
let metadata = FIRStorageMetadata()
metadata.contentType = "image/jpeg"
// 6
storageRef.child(imagePath).put(imageData!, metadata: metadata) { (metadata, error) in
if let error = error {
print("Error uploading photo: \(error)")
return
}
// 7
self.setImageURL(self.storageRef.child((metadata?.path)!).description, forPhotoMessageWithKey: key)
}
}
}
}
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
picker.dismiss(animated: true, completion:nil)
}
}
在我看来，这不是您所说的隐私问题，只是您在加载新对话时没有清除消息视图控制器上的数据。
最终这真的取决于你希望它有多安全；如果您很高兴将私人消息保存在内存中，那么在用户注销之前不要销毁它们——您甚至可以将多个私人对话保存在 CoreData 数据库中。这种方式还是比较安全的，方便用户和性能。如果您希望尽快销毁消息，请清除 viewDidDisappear 上的数据，然后检查您的 prepareForSegue 方法以再次清除数据。如果存储强引用不是您想要的，您也可以在每次关闭时销毁整个消息控制器。
这方面的一个例子，作为故事板：
- 应用加载
- 用户 1 已登录
- 用户1选择私信
- User1 与 User2 进行了对话
- User1 切换到与 User3 的对话
[伪代码]
userDidChangeRecipient { // destroy messages view controller // or destroy Firebase array data and destroy the reference to the message/conversation ID }
并且每次加载视图控制器时：
prepareForSegue {
if strongRefToMessagesVC == nil {
// instantiate a new instance of vc from nib or scratch
// load the appropriate message/conversation ID
// load messages
}
}
更多挖掘：
这里有两种可能：
切换消息时并没有破坏视图控制器，本教程希望您这样做。在这种情况下，您需要查看 segue 何时结束或用户关闭消息视图控制器并销毁它或清空数组。
您正在尝试将所有私人消息写入同一个
JSQMessage数组。我注意到在那个视图控制器中你有：var messageRef = FIRDatabase.database().reference().child("messages")这是您正在使用的数据库连接吗？每个私人消息对话都应该有一个唯一的参考 ID，这样它们就不会重叠，否则每个用户都会从 Firebase 加载同一组消息。