iOS Swift 2.0完成按鈕

Question

我正在嘗試向鍵盤添加一個完成按鈕。下面的代碼用於工作：

func addDoneButtonOnKeyboard() 
{ 
    let doneToolbar: UIToolbar = UIToolbar(frame: CGRectMake(0, 0, screenWidth, 50)) 
    //doneToolbar.barStyle = UIBarStyle.BlackTranslucent 

    let flexSpace = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.FlexibleSpace, target: nil, action: nil) 
    let done: UIBarButtonItem = UIBarButtonItem(title: "Done", style: UIBarButtonItemStyle.Done, target: self, action: Selector("doneButtonAction")) 

    var items: [UIBarButtonItem]? 
    items?.append(flexSpace) 
    items?.append(done) 

    doneToolbar.items = items 
    doneToolbar.sizeToFit() 
    commentsField.inputAccessoryView=doneToolbar 
} 

它將工具欄放在鍵盤上方，但沒有完成按鈕。

Answer 1

問題來自於線

var items: [UIBarButtonItem]? 

你的UIBarButtonItem陣列永遠不會初始化。將此行更換爲

var items: [UIBarButtonItem]? = [UIBarButtonItem]()