我有一个带标签栏控制器的应用程序。在一个选项卡中有一个导航控制器，它有一个ViewController。现在这个视图包含一个消息传递界面，我的问题是，添加了标签栏后，视图底部的文本框被切断了。为了解决这个问题，我做了一些研究并简单地添加了单行：
self.edgesForExtendedLayout = .None
解决了这个问题。我的文本框正在显示，用户可以选择并修改它等。但是当用户点击发送时，我的应用程序崩溃并显示以下消息：
fatal error: unexpectedly found nil while unwrapping an Optional value
我不知道问题是什么，因为在此之前一切都完美无缺......
我的ViewController的整个代码如下：
class ChatViewController: JSQMessagesViewController, CLLocationManagerDelegate {
// MARK: Properties
//Location
var city: String = ""
var state: String = ""
var country: String = ""
var locationManager = CLLocationManager()
var locationId: String = ""
func getLocation() -> String {
if city == ("") && state == ("") && country == (""){
return "Anonymous"
}
else {
if country == ("United States") {
return self.city + ", " + self.state
}
else {
return self.city + ", " + self.state + ", " + self.country
}
}
}
//Firebase
var rootRef = FIRDatabase.database().reference()
var messageRef: FIRDatabaseReference!
var locationRef: FIRDatabaseReference!
//JSQMessages
var messages = [JSQMessage]()
var outgoingBubbleImageView: JSQMessagesBubbleImage!
var incomingBubbleImageView: JSQMessagesBubbleImage!
override func viewDidLoad() {
super.viewDidLoad()
self.edgesForExtendedLayout = .None
locationManager.delegate = self
locationManager.requestWhenInUseAuthorization()
if CLLocationManager.locationServicesEnabled() {
//collect user's location
locationManager.desiredAccuracy = kCLLocationAccuracyThreeKilometers
locationManager.requestLocation()
locationManager.startUpdatingLocation()
}
title = "Group Chat"
setupBubbles()
// No avatars
collectionView!.collectionViewLayout.incomingAvatarViewSize = CGSizeZero
collectionView!.collectionViewLayout.outgoingAvatarViewSize = CGSizeZero
// Remove file upload icon
self.inputToolbar.contentView.leftBarButtonItem = nil;
messageRef = rootRef.child("messages")
locationRef = rootRef.child("locations")
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
observeMessages()
}
override func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
}
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
//--- CLGeocode to get address of current location ---//
CLGeocoder().reverseGeocodeLocation(manager.location!, completionHandler: {(placemarks, error)->Void in
if let pm = placemarks?.first
{
self.displayLocationInfo(pm)
}
})
}
func displayLocationInfo(placemark: CLPlacemark?)
{
if let containsPlacemark = placemark
{
//stop updating location
locationManager.stopUpdatingLocation()
self.city = (containsPlacemark.locality != nil) ? containsPlacemark.locality! : ""
self.state = (containsPlacemark.administrativeArea != nil) ? containsPlacemark.administrativeArea! : ""
self.country = (containsPlacemark.country != nil) ? containsPlacemark.country! : ""
print(getLocation())
}
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError) {
print("Error while updating location " + error.localizedDescription)
}
override func collectionView(collectionView: JSQMessagesCollectionView!,
messageDataForItemAtIndexPath indexPath: NSIndexPath!) -> JSQMessageData! {
return messages[indexPath.item]
}
override func collectionView(collectionView: JSQMessagesCollectionView!,
messageBubbleImageDataForItemAtIndexPath indexPath: NSIndexPath!) -> JSQMessageBubbleImageDataSource! {
let message = messages[indexPath.item] // 1
if message.senderId == senderId { // 2
return outgoingBubbleImageView
} else {
return incomingBubbleImageView
}
}
override func collectionView(collectionView: UICollectionView,
numberOfItemsInSection section: Int) -> Int {
return messages.count
}
override func collectionView(collectionView: JSQMessagesCollectionView!,
avatarImageDataForItemAtIndexPath indexPath: NSIndexPath!) -> JSQMessageAvatarImageDataSource! {
return nil
}
private func setupBubbles() {
let factory = JSQMessagesBubbleImageFactory()
outgoingBubbleImageView = factory.outgoingMessagesBubbleImageWithColor(
UIColor.jsq_messageBubbleBlueColor())
incomingBubbleImageView = factory.incomingMessagesBubbleImageWithColor(
UIColor.jsq_messageBubbleLightGrayColor())
}
func addMessage(id: String, text: String) {
let message = JSQMessage(senderId: id, displayName: "", text: text)
messages.append(message)
}
override 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
}
override func didPressSendButton(button: UIButton!, withMessageText text: String!, senderId: String!,
senderDisplayName: String!, date: NSDate!) {
let itemRef = messageRef.childByAutoId()
let messageItem = [
"text": text,
"senderId": senderId
]
itemRef.setValue(messageItem)
let locRef = locationRef.childByAutoId()
let locItem = [
senderId : [
"location": getLocation()
]
]
locRef.setValue(locItem)
// Retrieve data from Firebase Realtime database
FIRDatabase.database().reference().child("locations").child(senderId).child("location").observeSingleEventOfType(.Value, withBlock: { (snapshot) in
self.locationId = snapshot.value!["location"] as! String
}) { (error) in
print(error.localizedDescription)
}
JSQSystemSoundPlayer.jsq_playMessageSentSound()
finishSendingMessage()
}
private func observeMessages() {
let messagesQuery = messageRef.queryLimitedToLast(25)
messagesQuery.observeEventType(.ChildAdded) { (snapshot: FIRDataSnapshot!) in
let id = snapshot.value!["senderId"] as! String
let text = snapshot.value!["text"] as! String
self.addMessage(id, text: text)
self.finishReceivingMessage()
}
}
override func textViewDidChange(textView: UITextView) {
super.textViewDidChange(textView)
}
override func collectionView(collectionView: JSQMessagesCollectionView!, attributedTextForCellBottomLabelAtIndexPath indexPath: NSIndexPath!) -> NSAttributedString! {
let message = messages[indexPath.item]
// Call data I have retrieved below with message
let text = "From: " + locationId
if message.senderId == senderId {
return nil
} else {
return NSAttributedString(string: text)
}
}
override func collectionView(collectionView: JSQMessagesCollectionView, layout collectionViewLayout: JSQMessagesCollectionViewFlowLayout, heightForCellBottomLabelAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return kJSQMessagesCollectionViewCellLabelHeightDefault
}
}
提前感谢您的帮助！
答案 0 :(得分：0)
用户点击发送按钮后出现问题。我刚刚将行self.edgesForExtendedLayout = .None添加到特定操作中，它运行正常！