使用NSBundle时出错？

Question

我使用路径文档链接app中的外部文件。但是当我想在真正的iPhone上运行项目时，我用NSBundle替换了路径。现在我因为NSBundle（我认为）或其他原因而收到错误。我该如何调试呢？

控制台中的

错误：fatal error: unexpectedly found nil while unwrapping an Optional value

整个代码：

import UIKit

func assign() -> [String]{

    let bundle = NSBundle.mainBundle()
    let path = bundle.pathForResource("words", ofType: "txt")
    let content = String(contentsOfFile: path!, encoding: NSUTF8StringEncoding, error: nil)//xcode marked that line with green
    let newArray = content!.componentsSeparatedByString("\n")
    return newArray

}

class ViewController: UIViewController, UITextFieldDelegate {



    let newArray: [String] = assign()
    @IBOutlet weak var textBox: UITextView!
    @IBOutlet weak var firstInput: UITextField!
    @IBOutlet weak var resultLabel: UILabel!
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        firstInput.returnKeyType = .Search
        firstInput.delegate = self
        textBox.text = ""
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    func getFromPath() {
        //getFromPath() func used to be in assign func.
        var letters = firstInput.text
        var res = search(set: newArray, letters: letters)
        textBox.text! = ""
        for element in res {
            textBox.text = (textBox.text ?? "") + "\n" + "\(element)"
        }

    }

    func textFieldShouldReturn(textField: UITextField) -> Bool {
       if firstInput.text == "" {
       }
       else {
        getFromPath()
       }
        self.view.endEditing(true)
        return false
    }


    func search(#set: [String], letters: String) -> [String] {
        let result = filter(set) { item in
            for char in letters {
                if !contains(item, char) {
                    return false
                }
            }
            return true
        }
        return result
    }

}

Answer 1

好像你的捆绑包中没有该文件。

确保文件已添加到目标，请检查检查器。

在

中包装关键初始化

if let someObject = source as? someType
{

}

Answer 2

将文件拖到项目中，并将其与项目文件放在一起。如果需要，请务必选择复制项目：

class ViewController: UIViewController {
    let wordsUrl = NSBundle.mainBundle().URLForResource("words", withExtension: "txt")!
    override func viewDidLoad() {
        super.viewDidLoad()
        var error: NSError?

        if wordsUrl.checkResourceIsReachableAndReturnError(&error) {
            println(true)
            if let myString = String(contentsOfURL: wordsUrl, encoding: NSUTF8StringEncoding, error: &error) {
                let myArray = myString.componentsSeparatedByString("\n")
                println(myArray)
            } else if let error = error {
                println(error.description)
            }
        } else if let error = error {
            println(error.description)
        }
        // Do any additional setup after loading the view, typically from a nib.
    }

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