Question

我刚开始使用Swift，我希望在JSON中显示解析UITableView文件的结果。问题来自我的NSMutableArray新闻的初始化，其中包含要显示的所有对象。

我有错误：

error : "/Users/******/Documents/developper/******/*******
/NewsTableViewController.swift:79:22: 'NSMutableArray?' 
does not have a member named 'count'

代码是：

import UIKit

class NewsTableViewController: UITableViewController {

var bytes: NSMutableData?

// var news: NSArray = []

var news: NSMutableArray?

override func viewDidLoad() {
    super.viewDidLoad()

    // Uncomment the following line to preserve selection between presentations
    // self.clearsSelectionOnViewWillAppear = false

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem()



        // this is our remote end point (similar to URLRequest in AS3)
    let request = NSURLRequest(URL: NSURL(string: "http://mangerdulion.com/wp-content/newsInnoven.json")!)

    // this is what creates the connection and dispatches the varios events to track progression, etc.
    let loader = NSURLConnection(request: request, delegate: self, startImmediately: true)

}
func connection(connection: NSURLConnection!, didReceiveData conData: NSData!) {
    self.bytes?.appendData(conData)
}
func connection(didReceiveResponse: NSURLConnection!, didReceiveResponse response: NSURLResponse!) {
    self.bytes = NSMutableData()
}

func connectionDidFinishLoading(connection: NSURLConnection!) {

    // we serialize our bytes back to the original JSON structure
    let jsonResult: Dictionary = NSJSONSerialization.JSONObjectWithData(self.bytes!, options: NSJSONReadingOptions.MutableContainers, error: nil) as Dictionary<String, AnyObject>

    // we grab the colorsArray element
    let results: NSArray = jsonResult["newsArray"] as NSArray

    self.news?.addObjectsFromArray(results)
    /*
    // we iterate over each element of the colorsArray array
    for item in results {
        // we convert each key to a String
        var titre: String = item["titreNews"] as String
        var date: String = item["dateNews"] as String
        var contenu: String = item["contenuNews"] as String
        println("\(titre): \(date):\(contenu)")

    }
 */

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

// MARK: - Table view data source



override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // #warning Incomplete method implementation.
    // Return the number of rows in the section.

    //println(self.news?.count)

    return self.news.count

}


override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("reuseIdentifier", forIndexPath: indexPath) as UITableViewCell




    let titre: NSDictionary = self.news[indexPath.row] as NSDictionary

    cell.textLabel?.text = titre["titreNews"] as? String
    println(cell.textLabel?.text)


    // Get the formatted price string for display in the subtitle
    let contenu: NSString = titre["contenuNews"] as NSString

    cell.detailTextLabel?.text = contenu


    return cell
}

Answer 1

在课堂顶部创建一个可变数组，并且不要放任何＆＃34;？＆＃34;或＆＃34;！＆＃34;消息传出后。

var news: NSMutableArray = []

您还需要在connectionDidFinishLoading方法结束时在表视图上调用reloadData

Answer 2

在声明变量时将?字符放在类的末尾会创建一个Optional变量。 Optional个变量可以为nil或者值为Optional（value）。您必须打开Optional才能使用它。

var news:NSMutableArray?创建一个optional数组。

items?.count还将返回可选的Optional（Int）。这不能在UITableView计数方法中返回。

我认为你不需要在这里使用可选项。相反，为方便起见，您可以使用空数组。

var news: NSMutableArray = []

在Swift中初始化json文件的字典数组

2 个答案: