Xcode中的链接器错误？

Question

当我尝试在模拟器上运行我的应用程序时，出现一个奇怪的错误。 错误在以下代码/文件内。 （我不确定这叫什么）：

Undefined symbols for architecture i386:
"_main", referenced from:
implicit entry/start for main executable
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)   

上面的错误有两个部分以红色突出显示； "_main", referenced from:和linker command failed with exit code 1 (use -v to see invocation) 。

我以前从未遇到过此错误。 因此，我无法修复它。 如果有必要，这是我的代码：

class ViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()

}

@IBOutlet weak var strWordValue: UILabel!
@IBOutlet weak var strInputField: UITextField!


func textFieldShouldReturn(textField: UITextField) -> Bool{
    textField.resignFirstResponder()

    let word = textField.text
    let score = scoreForWord(word)

    return true
}

var TextField: UITextField!

        private let alphabet = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"]

func valueOfLetter(letter: Character) -> Int
{
let letterString = String(letter).uppercaseString
let index = find(alphabet, letterString)

return index != nil ? index! + 1 : 0
}

func scoreForWord(word: String) -> Int
{
    let characters = Array(word)
    return characters.reduce(0) { sum, letter in sum + self.valueOfLetter(letter) }


}

  func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool
  {
let currentWord = textField.text as NSString
let newWord = currentWord.stringByReplacingCharactersInRange(range, withString: string)

let score = scoreForWord(newWord)

return true
}
}

请说明此错误的含义。

Answer 1

这个错误消息已经在几个月前发生在我身上。 您的库不支持模拟器。 您需要在实际设备上而不是模拟器上运行。

Answer 2

这意味着实现main（）函数的文件未链接到可执行文件中。