Swift：NSString无法转换为“字符串”

Question

I am new to Swift and I am trying to return a group of rows into an array, but now I am trapped in a circle of errors. Any help would be appreciated. I am probably missing something, but it sure does not feel like it:

EDIT: Added code (Constraints for arrays not set).

func createButtonWithTitle(title: String) -> UIButton {

    let button = UIButton(type:.System) as UIButton
    button.translatesAutoresizingMaskIntoConstraints = false
    button.setTitle(title, forState: .Normal)
    button.sizeToFit()
    button.titleLabel!.font = UIFont.systemFontOfSize(15)
    button.backgroundColor = UIColor.greenColor()
    button.setTitleColor(UIColor.whiteColor(), forState: .Normal)

    return button
}

func createRowOfButtons(buttonTitles: [NSString]) -> UIView {

    var buttons = [UIButton]()
    let keyboardRowView = UIView()

    for buttonTitle in buttonTitles{

        let button = createButtonWithTitle(buttonTitle as String)
        buttons.append(button)
        keyboardRowView.addSubview(button)
    }

    addIndividualButtonConstraints(buttons, mainView: keyboardRowView)

    return keyboardRowView
}

func createArraysOfButtons (rowTitles: [NSString]) -> UIView{

    var rows = [UIView]()
    let keyArrayView = UIView()

    for rowTitle in rowTitles {
        if let title = rowTitle as? String{
            let row = createRowOfButtons(rowTitle as String)
            rows.append(row)
            keyArrayView.addSubview(row)
        }
    }
    return keyArrayView
}

Error Message:

'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?

Answer 1

Simplest solution: Do not use NSString

func createRowOfButtons(buttonTitles: [String]) -> UIView {

    var buttons = [UIButton]()
    let keyboardRowView = UIView()

    for buttonTitle in buttonTitles{

        let button = createButtonWithTitle(buttonTitle)
        buttons.append(button)
        keyboardRowView.addSubview(button)
    }

    addIndividualButtonConstraints(buttons, mainView: keyboardRowView)

    return keyboardRowView
}

func createArraysOfButtons (rowTitles: [String]) -> UIView{

    var rows = [UIView]()
    let keyArrayView = UIView()

    for rowTitle in rowTitles {
        let row = createRowOfButtons([rowTitle])
        rows.append(row)
        keyArrayView.addSubview(row)
    }
    return keyArrayView
}

The main issue is that createRowOfButtons expects an array of string but you're passing a single string to the method. createRowOfButtons([rowTitle]) solves that issue.