沒有textview的iphone鍵盤

Question

是否可以在沒有textview的iPhone應用程序中調出鍵盤？或者我將不得不有一個隱形的TextView？

如果是這樣，你如何編程創建一個文本視圖，然後調出鍵盤（用戶不必點擊文本視圖）？唯一的例子，我可以找到使用接口生成器..

Answer 1

唯一（有效）的方式來顯示鍵盤是有一個文本字段是第一響應者。 您可以通過在隱藏文本框中調用becomeFirstResponder來隱藏它，並以編程方式使其成爲第一響應者。

你可以做這樣的事情（假設aRect和觀點存在）

var textView = [[[UITextView alloc] initWithFrame:aRect] autorelease]; 
[view addSubview:textView]; 

[textView becomeFirstResponder]; 

Answer 2

這個東西的工作方式編程方式創建一個UITextView是通過NSNotificationCenter發佈/訂閱模式。首先，你需要使用addObserver:selector:name:object:，那麼你可以嘗試做this：

[[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:NSTextDidBeginEditingNotification object:self]]; 

但我不知道哪些通知會得到，或需要進行註冊，以獲取鍵盤輸入字符值。祝你好運，快樂的黑客:)

Answer 3

經過一些挖掘，我發現this。這是非官方的，但我敢打賭它是有效的。

UIKeyboard *keyboard = [[[UIKeyboard alloc] initWithFrame: CGRectMake(0.0f, contentRect.size.height - 216.0f, contentRect.size.width, 216.0f)] autorelease]; 
     [keyboard setReturnKeyEnabled:NO]; 
     [keyboard setTapDelegate:editingTextView]; 
     [inputView addSubview:keyboard]; 

Answer 4

UIKeyInput是你的朋友：

protocol KeyboardInputControlDelegate: class { 
    func keyboardInputControl(keyboardInputControl:KeyboardInputControl, didPressKey key:Character) 
} 

class KeyboardInputControl: UIControl, UIKeyInput { 

    // MARK: - properties 

    weak var delegate: KeyboardInputControlDelegate? 

    // MARK: - init 

    override init(frame: CGRect) { 
     super.init(frame: frame) 

     addTarget(self, action: Selector("onTouchUpInside:"), forControlEvents: .TouchUpInside) 
    } 

    required init(coder aDecoder: NSCoder) { 
     fatalError("init(coder:) has not been implemented") 
    } 

    // MARK: - UIView 

    override func canBecomeFirstResponder() -> Bool { 
     return true 
    } 

    // MARK: - methods 

    dynamic private func onTouchUpInside(sender: KeyboardInputControl) { 
     becomeFirstResponder() 
    } 

    // MARK: - UIKeyInput 

    var text:String = "" 

    func hasText() -> Bool { 
     return text.isEmpty 
    } 

    func insertText(text: String) { 
     self.text = text 
     for ch in text { 
      delegate?.keyboardInputControl(self, didPressKey: ch) 
     } 
    } 

    func deleteBackward() { 
     if !text.isEmpty { 
      let newText = text[text.startIndex..<text.endIndex.predecessor()] 
      text = newText 
     } 
    } 
} 

用法示例。點擊紅色視圖並查看Xcode控制檯輸出：

class ViewController: UIViewController, KeyboardInputControlDelegate { 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     let kic = KeyboardInputControl(frame: CGRect(x: 0, y: 0, width: 100, height: 100)) 
     kic.delegate = self 
     kic.backgroundColor = UIColor.redColor() 
     view.addSubview(kic) 
    } 

    func keyboardInputControl(keyboardInputControl: KeyboardInputControl, didPressKey key: Character) { 
     println("Did press: \(key)") 
    } 
} 

Answer 5

UIKeyInput是解決方案的關鍵。

protocol KeyboardInputControlDelegate: class { 
    func keyboardInputControl(keyboardInputControl:KeyboardInputControl, didPressKey key:Character) 
} 

class KeyboardInputControl: UIControl, UIKeyInput { 

    // MARK: - properties 

    weak var delegate: KeyboardInputControlDelegate? 

    // MARK: - init 

    override init(frame: CGRect) { 
     super.init(frame: frame) 

     addTarget(self, action: Selector("onTouchUpInside:"), forControlEvents: .TouchUpInside) 
    } 

    required init(coder aDecoder: NSCoder) { 
     fatalError("init(coder:) has not been implemented") 
    } 

    // MARK: - UIView 

    override func canBecomeFirstResponder() -> Bool { 
     return true 
    } 

    // MARK: - methods 

    dynamic private func onTouchUpInside(sender: KeyboardInputControl) { 
     becomeFirstResponder() 
    } 

    // MARK: - UIKeyInput 

    var text:String = "" 

    func hasText() -> Bool { 
     return text.isEmpty 
    } 

    func insertText(text: String) { 
     self.text = text 
     for ch in text { 
      delegate?.keyboardInputControl(self, didPressKey: ch) 
     } 
    } 

    func deleteBackward() { 
     if !text.isEmpty { 
      let newText = text[text.startIndex..<text.endIndex.predecessor()] 
      text = newText 
     } 
    } 
} 

示例用法。點擊紅色的視圖，看到Xcode控制檯輸出：

class ViewController: UIViewController, KeyboardInputControlDelegate { 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     let kic = KeyboardInputControl(frame: CGRect(x: 0, y: 0, width: 100, height: 100)) 
     kic.delegate = self 
     kic.backgroundColor = UIColor.redColor() 
     view.addSubview(kic) 
    } 

    func keyboardInputControl(keyboardInputControl: KeyboardInputControl, didPressKey key: Character) { 
     println("Did press: \(key)") 
    } 
}