Ios 以NSException Parse server类型的未捕获异常终止

我有一个名为“

fetchPosts

”的函数，当我将此函数添加到任何其他方法（如view Dod Display）或制作一个按钮以更新我获取的视图时，它将数据从解析服务器提取到

UicollectionViewController

”

以NSException类型的未捕获异常终止

“不知道这里有什么问题

import UIKit
import AVKit
import AVFoundation
import CoreLocation
import Parse

class NewsfeedCollectionViewController : UICollectionViewController, CLLocationManagerDelegate
{
    var searchController: UISearchController!
    var posts: [Post]?

    override func viewDidLoad() {
        super.viewDidLoad()

        if let user = PFUser.current() {
            PFGeoPoint.geoPointForCurrentLocation { (geopoint, error) in
                if geopoint != nil {
                    let geo = geopoint
                    user["location"] = geo
                    user.saveInBackground()
                }
            }
        }

        self.fetchPosts()
        collectionView?.contentInset = UIEdgeInsets(top: 12, left: 4, bottom: 12, right: 4)

        if let layout = collectionView?.collectionViewLayout as? PinterestLayout {
            layout.delegate = self
        }
    }

    func fetchPosts()
    {
        DispatchQueue.global(qos: .userInteractive).async {
            self.posts = Post.fetchPosts(viewController: self)

            DispatchQueue.main.async {
                self.collectionView?.reloadData()
            }
        }
    }



    @IBAction func reloadbtnPressed(_ sender: Any) {
        fetchPosts()
    }


}

extension NewsfeedCollectionViewController
{
    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        if let posts = posts {
            return posts.count
        } else {
            return 0
        }
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
    {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "PostCell", for: indexPath) as! PostCollectionViewCell
        cell.post = self.posts?[indexPath.item]
        return cell
    }
}

extension NewsfeedCollectionViewController : PinterestLayoutDelegate
{
    func collectionView(collectionView: UICollectionView, heightForPhotoAt indexPath: IndexPath, with width: CGFloat) -> CGFloat
    {
        if let post = posts?[indexPath.item], let _ = post.image {
            let boundingRect = CGRect(x: 0, y: 0, width: width, height: CGFloat(MAXFLOAT))
//            do {
//                try postImageView.image = UIImage(data: image!.getData())
//            }
//            catch {
//
//            }
            do {
                var image: UIImage
                try image = UIImage(data: post.image!.getData())!
                let rect = AVMakeRect(aspectRatio: image.size, insideRect: boundingRect)
                return rect.size.height
            }
            catch {
                return 1;
            }

        }

        return 0
    }

    func collectionView(collectionView: UICollectionView, heightForCaptionAt indexPath: IndexPath, with width: CGFloat) -> CGFloat
    {
        if let post = posts?[indexPath.item] {
            let topPadding = CGFloat(8)
            let bottomPadding = CGFloat(12)
            let captionFont = UIFont.systemFont(ofSize: 15)
            let captionHeight = self.height(for: post.caption!, with: captionFont, width: width)
            let profileImageHeight = CGFloat(36)
            let height = topPadding + captionHeight + topPadding + profileImageHeight + bottomPadding

            return height
        }

        return 0.0
    }

    func height(for text: String, with font: UIFont, width: CGFloat) -> CGFloat
    {
        let nsstring = NSString(string: text)
        let maxHeight = CGFloat(64.0)
        let textAttributes = [NSFontAttributeName : font]
        let boundingRect = nsstring.boundingRect(with: CGSize(width: width, height: maxHeight), options: .usesLineFragmentOrigin, attributes: textAttributes, context: nil)
        return ceil(boundingRect.height)
    }
}

extension NewsfeedCollectionViewController : PostProtocol
{
    func didFinishFetch(posts: [Post]?)
    {
        if (posts != nil) {
            self.posts = posts
        }
        self.collectionView?.reloadData()
    }
}

下面是我用来从服务器获取数据的模型Post文件：

import UIKit
import Parse

protocol PostProtocol: class {
    func didFinishFetch(posts: [Post]?)
}

struct Post
{
    var ID: String
    var createdBy: User
    var timeAgo: String?
    var caption: String?
//    var image: UIImage?
    var image: PFFile?
    var numberOfLikes: Int?
    var numberOfComments: Int?
    var numberOfShares: Int?

    static weak var delegate: PostProtocol?

    static func fetchPosts(viewController: PostProtocol) -> [Post]
    {
        var posts = [Post]()
        delegate = viewController

        let query = PFQuery(className: "posts");
        if let latitude = (PFUser.current()?["location"] as AnyObject).latitude {
            if let longitude = (PFUser.current()?["location"] as AnyObject).longitude {
                let geoPoint = PFGeoPoint(latitude: latitude, longitude: longitude)
                query.whereKey("postLocation", nearGeoPoint: geoPoint, withinKilometers: 1)
            }
        }
        query.findObjectsInBackground { (objects: [PFObject]?, error: Error?) in
            if error == nil {
                for object in objects! {
                    let pfObject = object as PFObject
                    let ID = pfObject["uuid"] as! String
                    let caption = pfObject["title"] as! String
                    let likes = pfObject["likes"] as? Int
                    let comments = pfObject["comments"] as? Int
                    let shares = pfObject["shares"] as? Int
                    let image = pfObject["pic"] as? PFFile

                    let profileImage = pfObject["ava"] as? PFFile
                    let username = pfObject["username"] as? String
                    let user = User(username: username, profileImage: profileImage);

                    let from = pfObject.createdAt
                    let now = Date()
                    let components : NSCalendar.Unit = [.second, .minute, .hour, .day, .weekOfMonth]
                    let difference = (Calendar.current as NSCalendar).components(components, from: from! as Date, to: now, options: [])
                    var timeAgo: String = ""
                    // logic what to show: seconds, minuts, hours, days or weeks
                    if difference.second! <= 0 {
                        timeAgo = "now"
                    }
                    if difference.second! > 0 && difference.minute! == 0 {
                        timeAgo = "\(difference.second!)s."
                    }
                    if difference.minute! > 0 && difference.hour! == 0 {
                        timeAgo = "\(difference.minute!)m."
                    }
                    if difference.hour! > 0 && difference.day! == 0 {
                        timeAgo = "\(difference.hour!)h."
                    }
                    if difference.day! > 0 && difference.weekOfMonth! == 0 {
                        timeAgo = "\(difference.day!)d."
                    }
                    if difference.weekOfMonth! > 0 {
                        timeAgo = "\(difference.weekOfMonth!)w."
                    }

                    let post = Post(ID: ID, createdBy: user, timeAgo: timeAgo, caption: caption, image: image, numberOfLikes: likes, numberOfComments: comments, numberOfShares: shares)
                    posts.append(post);
                }
                delegate?.didFinishFetch(posts: posts)
            }
        }


        return posts
    }
}

struct User
{
    var username: String?
    var profileImage: PFFile?
}

导入UIKit
导入解析
协议后协议：类{
func didfishfetch（posts:[Post]？）
}
结构柱
{
变量ID:String
var createdBy:User
var timeAgo:字符串？
变量标题：字符串？
//var图像：UIImage？
var图像：PFFile？
var numberOfLikes:Int？
var numberOfComments:Int？
var numberOfShares:Int？
静态弱var委托：后协议？
静态函数fetchPosts（viewController:PostProtocol）->[Post]
{
var posts=[Post]（）
委托=视图控制器
let query=PFQuery（类名：“posts”）；
如果让纬度=（PFUser.current（）？[“location”]作为任何对象）。纬度{
如果让经度=（PFUser.current（）？[“location”]作为任何对象）。经度{
let geoPoint=PFGeoPoint（纬度：纬度，经度：经度）
query.whereKey（“postLocation”，nearGeoPoint:geoPoint，withinKilometers:1）
}
}
query.findObjectsInBackground{（对象：[PFObject]？，错误：error？）位于
如果错误==nil{
对于对象中的对象{
将pfObject=对象设为pfObject
让ID=pfObject[“uuid”]作为！字符串
将caption=pfObject[“title”]设为！字符串
让likes=pfObject[“likes”]as？Int
将comments=pfObject[“comments”]设为？Int
将shares=pfObject[“shares”]设为？Int
将image=pfObject[“pic”]设为PFFile
将profileImage=pfObject[“ava”]设为？PFFile
将username=pfObject[“username”]设为？字符串
让user=user（用户名：username，profileImage:profileImage）；
let from=pfObject.createdAt
让我们现在=日期（）
let组件：NSCalendar.Unit=[.second、.minute、.hour、.day、.weekOfMonth]
让差异=（Calendar.current作为NSCalendar）。组件（组件，from:from！作为日期，to:now，选项：[]）
var timeAgo:String=“”
//逻辑显示：秒、分钟、小时、天或周
如果difference.second！0&&difference.minute！==0{
timeAgo=“\（差。秒！）s。”
}
如果difference.minute！>0&&difference.hour！==0{
timeAgo=“\（差。分钟！）m。”
}
如果difference.hour！>0&&difference.day！==0{
timeAgo=“\（差。小时！）h。”
}
如果difference.day！>0&&difference.weekOfMonth！==0{
timeAgo=“\（差异.天！）d。“
}
如果差异.weekOfMonth！>0{
timeAgo=“\（差异。周/月！）w。“
}
让post=post（ID:ID，createdBy:user，timeAgo:timeAgo，caption:caption，image:image，numberOfLikes:likes，numberOfComments:comments，numberOfShares:shares）
职位。追加（职位）；
}
代理？.didfishfetch（posts:posts）
}
}
返回岗位
}
}
结构用户
{
var用户名：字符串？
var profileImage:PFFile？
}

1）能否提供UIImage的getData（）方法的代码？看起来它是UIImage扩展中的一个方法。2） 为什么称之为：try image=UIImage（数据：post.image！.getData（））！我尝试了image post.image，但出现了一个错误，无法将image类型转换为PFFile类型。open func getData（）抛出->Data/**此方法类似于

-getData

，但避免将整个

PFFile

内容一次保存在内存中@指向将在必要时设置的

n错误的param error指针@返回包含数据的流。如果提取时出错，则返回nil*/尝试检查数据是否可用并打印异常错误：if post.image？.isDataAvailable{var image:UIImage？do{let data=try post.image？.getData（）image=UIImage（data:data）}catch{print（“发生错误：（error.localizedDescription）“}}我已经这样做了，但是我仍然得到了相同的错误！问题是函数“fetchPosts”在我用于ViewDidLoad时工作正常，并且它实际上在CollectionVIew上加载了文章，但是当我尝试在任何其他方法中重用时，我得到了这个错误。你能提供错误描述吗？