快速搜索栏和表格视图-致命错误：在展开可选值时意外发现nil

Question

I'm trying to make a search facility on my tableview by using "Search Bar Search Display Controller" like when user touches a letter it will only display those items in the tableview. Item's on tableview are fetched from a webservice. I was following this tutorial: Link

And i cannot get away with this error message:

fatal error: unexpectedly found nil while unwrapping an Optional value

And i think it might be about searchingDataArray . I tried some debugging and made some search on google and examined suggestions on various sites including here but yet failed to fix the problem and now i'm little bit confused. Below you can see my code. How can fix it?

//
//  ThirdViewController.swift
//  myApp
//
//  Created by Timur Aykut Yildirim on 17/03/15.
//  Copyright (c) 2015 Timur Aykut Yildirim. All rights reserved.
//

import UIKit

class ThirdViewController: UIViewController, UISearchBarDelegate, UITableViewDelegate, UITableViewDataSource {

    @IBOutlet var manufacturerSearchBar: UISearchBar!
    @IBOutlet var allManufacturers: UITableView!

    var myData:NSMutableArray = NSMutableArray()

    var is_searching:Bool! // flag for whether search is active or not
    var searchingDataArray:NSMutableArray! // sorted search results will be here

    func getAllManufacturers(){
        var url : String = "http://00.00.000.000/myWebService"
        var request : NSMutableURLRequest = NSMutableURLRequest()
        request.URL = NSURL(string: url)
        request.HTTPMethod = "GET"

        NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue(), completionHandler:{ (response:NSURLResponse!, data: NSData!, error: NSError!) -> Void in
            var error: AutoreleasingUnsafeMutablePointer<NSError?> = nil
            let jsonResult: NSDictionary! = NSJSONSerialization.JSONObjectWithData(data, options:NSJSONReadingOptions.MutableContainers, error: error) as? NSDictionary

            if (jsonResult != nil) {

                var userMomentList:NSMutableArray = NSMutableArray()

                self.myData = jsonResult.objectForKey("result") as NSMutableArray
                //println("AAAAAAAAAAAAA")
                println("this is myData dude: \(self.myData)")
                dispatch_async(dispatch_get_main_queue(), {
                    self.allManufacturers.reloadData()
                })
                //println("QQQQQQQQQQQQQ")
            } else {
                // couldn't load JSON, look at error
                println("jsonResult is nil")
            }
        })
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        getAllManufacturers()
        //println("this is myData: \(myData)")
        is_searching = false
        self.allManufacturers.registerClass(UITableViewCell.self, forCellReuseIdentifier: "allMAN_cell_identifier")

    }

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


    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if is_searching == true{
            return self.searchingDataArray.count
        }
        else{
            return self.myData.count  //Currently Giving default Value
        }
    }


    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell:UITableViewCell = UITableViewCell(style: UITableViewCellStyle.Value1, reuseIdentifier: "allMAN_cell_identifier")

        if is_searching == true {
            cell.textLabel?.text = searchingDataArray[indexPath.row] as NSString
        }
        else {
            var data = self.myData.objectAtIndex(indexPath.row) as NSDictionary
            cell.textLabel?.text = data.objectForKey("text") as NSString
            //cell.detailTextLabel?.text = data.objectForKey("item_value") as NSString
        }

        return cell
    }


    func tableView(tableView: UITableView!, didSelectRowAtIndexPath indexPath: NSIndexPath!) {

        let chosenCell = tableView.cellForRowAtIndexPath(indexPath)! as UITableViewCell;
        // println(chosenCell.textLabel!.text!)
        let alert = UIAlertController(title: "Item selected", message: "You selected item \(indexPath.row+1) and it's: \(chosenCell.textLabel!.text!)", preferredStyle: UIAlertControllerStyle.Alert)
        alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Cancel, handler: nil))
        self.presentViewController(alert, animated: true, completion: nil)

        if (chosenCell.accessoryType == UITableViewCellAccessoryType.Checkmark) {
            chosenCell.accessoryType = UITableViewCellAccessoryType.None;
        } else {
            chosenCell.accessoryType = UITableViewCellAccessoryType.Checkmark;
        }

    }

    // this method does all the search trick
    func searchBar(searchBar: UISearchBar, textDidChange searchText: String){
        if searchBar.text.isEmpty{
            is_searching = false
            allManufacturers.reloadData()
        } else {
            println(" search text %@ ",searchBar.text as NSString)
            is_searching = true
            searchingDataArray.removeAllObjects()
            for var index = 0; index < myData.count; index++
            {
                var currentString = myData.objectAtIndex(index) as String
                if currentString.lowercaseString.rangeOfString(searchText.lowercaseString)  != nil {
                    searchingDataArray.addObject(currentString)

                }
            }
            allManufacturers.reloadData()
        }
    }
}

Answer 1

Problem with your "searchingDataArray" declaration.

Your code:

var searchingDataArray:NSMutableArray!  

Needs to be like the following:

var searchingDataArray:NSMutableArray = NSMutableArray()