我刚刚下载了
Xcode 8 Beta,因此我可以在我的应用程序中包含一些新的iOS 10框架.但是,在将我的代码从
Swift 2转换为
Swift 3的过程中,我遇到了几个错误.除了一个超级烦人之外我修好了.
我收到错误：
Cannot call value of non-function type ‘JSQMessagesCollectionView!’ at the following line of code:
let cell = super.collectionView(collectionView,cellForItemAtIndexPath: indexPath) as! JSQMessagesCollectionViewCell
这是我的整个上下文功能：
func collectionView(collectionView: UICollectionView,cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell{
let cell = super.collectionView(collectionView,cellForItemAtIndexPath: indexPath) as! JSQMessagesCollectionViewCell
let message = messages[indexPath.item]
if message.senderId == senderId {
cell.textView!.textColor = UIColor.whiteColor()
} else {
cell.textView!.textColor = UIColor.blackColor()
}
return cell
}
有人有想法吗？
附：如果这有帮助,这是我的整个代码块：
import UIKit
import Firebase
import JSQMessagesViewController
class ChatViewController: JSQMessagesViewController {
// MARK: Properties
var rootRef = FIRDatabase.database().reference()
var messageRef: FIRDatabaseReference!
var messages = [JSQMessage]()
var outgoingBubbleImageView: JSQMessagesBubbleImage!
var incomingBubbleImageView: JSQMessagesBubbleImage!
var userIsTypingRef: FIRDatabaseReference! // 1
private var localTyping = false // 2
var isTyping: Bool {
get {
return localTyping
}
set {
// 3
localTyping = newValue
userIsTypingRef.setValue(newValue)
}
}
var usersTypingQuery: FIRDatabaseQuery!
override func viewDidLoad() {
super.viewDidLoad()
// Change the navigation bar background color to blue.
// navigationController!.navigationBar.barTintColor = UIColor.init(red:252/255,green: 87/255,blue: 68/255,alpha: 1)
navigationController!.navigationBar.barTintColor = UIColor.init(red:250/255,green: 69/255,blue: 85/255,alpha: 1)
title = "RoastChat"
setupBubbles()
// No avatars
collectionView!.collectionViewLayout.incomingAvatarViewSize = CGSize.zero
collectionView!.collectionViewLayout.outgoingAvatarViewSize = CGSize.zero
// Remove file upload icon
self.inputToolbar.contentView.leftBarButtonItem = nil;
messageRef = rootRef.child("messages")
}
func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
observeMessages()
observeTyping()
}
func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
}
func collectionView(collectionView: JSQMessagesCollectionView!,messageDataForItemAtIndexPath indexPath: NSIndexPath!) -> JSQMessageData! {
return messages[indexPath.item]
}
func collectionView(collectionView: JSQMessagesCollectionView!,messageBubbleImageDataForItemAtIndexPath indexPath: NSIndexPath!) -> JSQMessageBubbleImageDataSource! {
let message = messages[indexPath.item] // 1
if message.senderId == senderId { // 2
return outgoingBubbleImageView
} else { // 3
return incomingBubbleImageView
}
}
func collectionView(collectionView: UICollectionView,numberOfItemsInSection section: Int) -> Int {
return messages.count
}
func collectionView(collectionView: JSQMessagesCollectionView!,avatarImageDataForItemAtIndexPath indexPath: NSIndexPath!) -> JSQMessageAvatarImageDataSource! {
return nil
}
private func setupBubbles() {
let factory = JSQMessagesBubbleImageFactory()
outgoingBubbleImageView = factory?.outgoingMessagesBubbleImage(
// UIColor.init(red:250/255,alpha: 1))
with: UIColor.init(red:47/255,green: 53/255,blue: 144/255,alpha: 1))
incomingBubbleImageView = factory?.incomingMessagesBubbleImage(
with: UIColor.jsq_messageBubbleLightGray())
}
func addMessage(id: String,text: String) {
let message = JSQMessage(senderId: id,displayName: "",text: text)
messages.append(message!)
}
func collectionView(collectionView: UICollectionView,cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell{
let cell = super.collectionView(collectionView,cellForItemAtIndexPath: indexPath) as! JSQMessagesCollectionViewCell
let message = messages[indexPath.item]
if message.senderId == senderId {
cell.textView!.textColor = UIColor.whiteColor()
} else {
cell.textView!.textColor = UIColor.blackColor()
}
return cell
}
func didPressSendButton(button: UIButton!,withMessageText text: String!,senderId: String!,senderDisplayName: String!,date: NSDate!) {
let itemRef = messageRef.childByAutoId() // 1
let messageItem = [ // 2
"text": text,"senderId": senderId
]
itemRef.setValue(String(messageItem)) // 3
// 4
JSQSystemSoundPlayer.jsq_playMessageSentSound()
// 5
finishSendingMessage()
isTyping = false
}
private func observeMessages() {
// 1
let messagesQuery = messageRef.queryLimited(toLast: 25)
// 2
messagesQuery.observe(.childAdded) { (snapshot: FIRDataSnapshot!) in
// 3
let id = snapshot.value!["senderId"] as! String
let text = snapshot.value!["text"] as! String
// 4
self.addMessage(id: id,text: text)
// 5
self.finishReceivingMessage()
}
}
private func observeTyping() {
let typingIndicatorRef = rootRef.child("typingIndicator")
userIsTypingRef = typingIndicatorRef.child(senderId)
userIsTypingRef.onDisconnectRemoveValue()
// 1
usersTypingQuery = typingIndicatorRef.queryOrderedByValue().queryEqual(toValue: true)
// 2
usersTypingQuery.observe(.value) { (data: FIRDataSnapshot!) in
// 3 You're the only typing,don't show the indicator
if data.childrenCount == 1 && self.isTyping {
return
}
// 4 Are there others typing?
self.showTypingIndicator = data.childrenCount > 0
self.scrollToBottom(animated: true)
}
}
func textViewDidChange(textView: UITextView) {
super.textViewDidChange(textView)
// If the text is not empty,the user is typing
isTyping = textView.text != ""
}
func collectionView(collectionView: JSQMessagesCollectionView!,attributedTextForCellBottomLabelAtIndexPath indexPath: NSIndexPath!) -> AttributedString! {
return AttributedString(string:"test")
}
}
尝试将方法更改为：
override func collectionView(_ collectionView: UICollectionView,cellForItemAt indexPath: NSIndexPath) -> UICollectionViewCell{
let cell = super.collectionView(collectionView,cellForItemAt: indexPath) as! JSQMessagesCollectionViewCell
let message = messages[indexPath.item]
if message.senderId == senderId {
cell.textView!.textColor = UIColor.whiteColor()
} else {
cell.textView!.textColor = UIColor.blackColor()
}
return cell
}
如果您正在正确编写重写方法,Swift会抱怨缺少override关键字.因此,如果您在此重写方法上找不到任何警告或错误,则很可能会滥用方法签名.
并且许多UICollectionViewDataSources方法都被重命名,在Swift3中“cellForItemAtIndexPath”有这个签名：
func collectionView(_ collectionView: UICollectionView,cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
所以,Swift找不到匹配collectionView(_：cellForItemAtIndexPath :)的方法定义,所以假设collectionView会有一个属性. (不幸的是,它在JSQMessagesViewController中声明.)
您可能在类中有这种不匹配的方法实现.更好地检查它们.
