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我无法将图像返回到tableView单元格。UIImage返回零从JSON请求到MySQL数据库的tableView细胞图像？
当我改变所有recipientImg参数字符串一切都正常运行，但是当我改变recipientImg参数的UIImage我得到（数据下载 致命错误：意外发现零而展开的可选值） （LLDB）
Ps我试图返回数据库中的文件路径作为图像。其他两个字符串作为字符串在tableView中返回，但我无法获取imageView以返回图像。
任何提示？
This is the JSON file on the server from the database 我也正在使用RecipientImg为[VARCHAR]在数据库
这里是viewermodel1.swift
import UIKit
class viewedMeModel1: NSObject {
//properties
var username: String?
var messageDetail: String?
var recipientImg: UIImage?
//empty constructor
override init()
{
}
//construct with parameters
init(username: String, messageDetail: String, recipientImg: UIImage) {
self.username = username
self.messageDetail = messageDetail
self.recipientImg = recipientImg
}
//prints object's current state
}
这里是viewedMeModel2.swift
import UIKit
protocol viewedMeModel2Protocol: class {
func itemsDownloaded(items: NSArray)
}
class viewedMeModel2: NSObject {
weak var delegate: viewedMeModel2Protocol!
var data = Data()
let urlPath: String = "http://" //this will be changed to the path where .php lives
func downloadItems() {
let url: URL = URL(string: urlPath)!
let defaultSession = Foundation.URLSession(configuration: URLSessionConfiguration.default)
let task = defaultSession.dataTask(with: url) { (data, response, error) in
if error != nil {
print("Failed to download data")
}else {
print("Data downloaded")
self.parseJSON(data!)
}
}
task.resume()
}
func parseJSON(_ data:Data) {
var jsonResult = NSArray()
do{
jsonResult = try JSONSerialization.jsonObject(with: data, options:JSONSerialization.ReadingOptions.allowFragments) as! NSArray
} catch let error as NSError {
print(error)
}
var jsonElement = NSDictionary()
let locations = NSMutableArray()
for i in 0 ..< jsonResult.count
{
jsonElement = jsonResult[i] as! NSDictionary
let location = viewedMeModel1()
//the following insures none of the JsonElement values are nil through optional binding
if let username = jsonElement["Username"] as? String,
let messageDetail = jsonElement["MessageDetail"] as? String,
let recipientImg = jsonElement["RecipientImg"] as? UIImage
{
location.username = username
location.messageDetail = messageDetail
location.recipientImg = recipientImg
}
locations.add(location)
}
DispatchQueue.main.async(execute: {() -> Void in
self.delegate.itemsDownloaded(items: locations)
})
}
}
这里is viewedMeController.swift import UIKit
class ViewerViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, viewedMeModel2Protocol {
var feedItems: NSArray = NSArray()
var selectedLocation : viewedMeModel1 = viewedMeModel1()
@IBOutlet weak var viewedMe: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
self.viewedMe.delegate = self
self.viewedMe.dataSource = self
let ViewedMeModel2 = viewedMeModel2()
ViewedMeModel2.delegate = self
ViewedMeModel2.downloadItems()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func itemsDownloaded(items: NSArray) {
feedItems = items
self.viewedMe.reloadData()
}
func numberOfSections(in tableView: UITableView) -> Int {
return feedItems.count
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// Return the number of feed items
return feedItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
// Retrieve cell
let cellIdentifier: String = "basicCell"
let cell: UITableViewCell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier)!
// Get the location to be shown
let item: viewedMeModel1 = feedItems[indexPath.row] as! viewedMeModel1
// Get references to labels of cell
cell.UIImage?.image = item.recipientImg!
return cell
}
和一个队友的话，你的命名约定是非常糟糕的，你应该总是使用大写的名称类和协议，以及骆驼套管的变量名。 –