如何创建一个类并返回一些东西。 迅速

Question

I am trying to create multiple languages for my app, so I want to translate a English word to a different language word, but I am not sure how to create a class and return the translated word like Translate("hello") and it would return 你好 . Any suggestions instead of creating a function as I don't want to do something like Translate().convert("hello") and get the return of "你好"? Thanks.

class Translate {
    let englishToChineseDict = [
                                "hello": "你好",
                                "hi": "你好"
                               ]
    init(english: String) {
        let word = englishToChineseDict[english]
    }
}

Answer 1

Since there are no properties to initialize an init method is not needed but a translate method.

class Translate {
    let englishToChineseDict = [
                                "hello": "你好",
                                "hi": "你好"
                               ]
    func translate(english : String) -> String {

      if let result = englishToChineseDict[english] {
         return result
      } else {
         return "The term \(english) is not in the dictionary"
      }
    }
}

And use it by creating an instance of the class and call the method

let translator = Translate()
let chinese = translator.translate("hi")

---

Alternatively use a static class

static let englishToChineseDict = [ ...
...
class func translate( ...

and call it

let chinese = Translate.translate("hi")

Edit :

Swift classes don't return anything (with the exception nil in a failable initializer) but as a workaround you could implement the CustomStringConvertible protocol which changes the class pointer to a string representation.

class Translate : CustomStringConvertible {
  let englishToChineseDict = [ "hello": "你好", "hi": "你好" ]

  var english : String

  init(_ english : String) {
    self.english = english
  }

  var description : String {

    if let result = englishToChineseDict[english] {
      return result
    } else {
      return "The term \(english) is not in the dictionary"
    }
  }
}


let chinese = Translate("hi")
print(chinese) // "你好"

Answer 2

init method is used to initialize the property of object, try to create another function and use that like this

class Translate: NSObject {

    struct Static {
        static var instance: Translate?
    }

    class func sharedManager() -> Translate {
        if (Static.instance == nil)
        {
            Static.instance = Translate()
        }
        return Static.instance!
    }

    let englishToChineseDict = [
        "hello": "你好",
        "hi": "你好"
    ]

    func translateWord(english: String) -> String {
        if let word = englishToChineseDict[english] {
            return word
        }
        else { 
            return "Chinese word not found for english word \(english)"
        }
    }
}

Now call this method like this

let str = Translate.sharedManager().translateWord("hello")

Note: I have created shared (singleton) object of the Translate class, so you can access singleton object from Any class using sharedManager method. So you no need create new instance of of Translate class.

Edit:

class Translate: NSObject {

    let englishToChineseDict = [
        "hello": "你好",
        "hi": "你好"
    ]

    var translatedWord = String()
    var isTranslated = false

    init(english: String) -> String {
        if let word = englishToChineseDict[english] {
            translatedWord = word
            isTranslated = true
        }
    }
}

Now you can call like this

let translate = Translate("Hello")
if translate.isTranslate {
    print(translate.translatedWord)
}

Answer 3

To make your app support multiple languages, first you need to add the localization in the project settings:

Select your project file on the left pane, then add a localization in the "Localizations" section:

Click the "+" button and select Chinese (Traditional), check all the checkboxes:

I recommend you to also localize to Simplified Chinese. So after checking those checkboxes, the thing should look like this:

You will see that some new .strings files are added to the project:

You can localize your app just by editing these files. In the files, you will see something like this:

"uel-mS-zq9.text" = "some text";

You basically translate the right hand side of the = sign to the desired language. Simple as this:

"uel-mS-zq9.text" = "一些文字";

And you do this for all the text that needs translating.

But sometimes, some text that needs translations is not in the storyboard. To translate those, you need to create a new file called Localizable.strings and check these checkboxes on the file inspector:

Again, you'll find a Localizable.strings file created for each of the localizations.

If you write something like:

"Settings" = "設定";

in the Traditional Chinese file, calling NSLocalizedString("Settings", comment: "") will return 設定.

For more info, you can check this or this out.