承上篇 - iOS - 客製化Dialog
若Dialog中有 TextField的時候, 可能會被軟體鍵盤所蓋住
因此必須使用動態調整Dialog的方式來解決.
Step 1: 監聽與取消監聽軟體鍵盤變化
在viewWillAppear監聽軟體鍵盤變化
在viewWillDisappear取消監聽
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| override func viewWillAppear(animated: Bool) {
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(Dialog.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(Dialog.keyboardWillHidden(_:)), name: UIKeyboardWillHideNotification, object: nil)
}
override func viewWillDisappear(animated: Bool) {
NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
}
func keyboardWillShow(notification: NSNotification) {
}
func keyboardWillHidden(notification: NSNotification) {
}
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Step 2: Reference TextField and 監聽TextField選取變化
如果有多個TextField時, 每個TextField的位置都不一樣, 所以我們必須得知目前被選到的TextField是哪一個.
設立變數
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| var selectedEditText : UITextField?
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註冊TextField delegate
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| @IBOutlet weak var mEditText: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
mEditText.delegate = self;
}
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監聽TextField選取變化
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| extension Dialog : UITextFieldDelegate {
func textFieldDidBeginEditing(textField: UITextField) {
selectedEditText = textField
}
func textFieldShouldReturn(textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
func textFieldDidEndEditing(textField: UITextField) {
selectedEditText = nil
}
}
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Step 3: 將畫面向上調整
由於我們需要計算Dialog View在整個Frame的y軸位置, 所以必須先reference Dialog View後, 再使用mDialogView.frame.origin.y 得知y軸位置.
取得鍵盤高度
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| func keyboardWillShow(notification: NSNotification) {
let userInfo: NSDictionary? = notification.userInfo
let aValue: NSValue? = userInfo?.objectForKey(UIKeyboardFrameEndUserInfoKey) as? NSValue
let keyboardRect = aValue?.CGRectValue()
let keyboardHeight = keyboardRect?.size.height
}
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計算輸入框和鍵盤高度的差值
由上圖得知 self.view.frame.size.height - keyboardHeight = 畫面剩餘空間
若mDialogVIew.frame.origin.y + frame.origin.y 的數值大於畫面剩餘空間的話,
表示輸入框會被鍵盤所覆蓋.
所以我們利用此公式來算出差值.
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| let offset = frame.origin.y + mDialogView.frame.origin.y + 36 - (self.view.frame.size.height - keyboardHeight!)
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36 這個數值可根據文字的大小來動態調整, 或者使用輸入框的高度
使用動畫來調整畫面
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| UIView.animateWithDuration(0.3, animations: { () -> Void in
if (offset > 0) {
self.view.frame.origin.y -= offset;
} else {
self.view.frame.origin.y = 0;
}
})
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Step 4: 輸入完畢後, 恢復畫面位置
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| func keyboardWillHidden(notification: NSNotification) {
UIView.animateWithDuration(0.3, animations: { () -> Void in
self.view.frame.origin.y = 0;
})
}
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執行結果
Source Code
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| import UIKit
class Dialog: UIViewController {
@IBOutlet weak var mEditText: UITextField!
@IBOutlet weak var mDialogView: UIView!
var selectedEditText : UITextField?
override func viewDidLoad() {
super.viewDidLoad()
mEditText.delegate = self;
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
override func viewWillAppear(animated: Bool) {
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(Dialog.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(Dialog.keyboardWillHidden(_:)), name: UIKeyboardWillHideNotification, object: nil)
}
override func viewWillDisappear(animated: Bool) {
NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
}
func keyboardWillShow(notification: NSNotification) {
let userInfo: NSDictionary? = notification.userInfo
let aValue: NSValue? = userInfo?.objectForKey(UIKeyboardFrameEndUserInfoKey) as? NSValue
let keyboardRect = aValue?.CGRectValue()
let keyboardHeight = keyboardRect?.size.height
let frame = selectedEditText!.frame
let offset = frame.origin.y + mDialogView.frame.origin.y + 36 - (self.view.frame.size.height - keyboardHeight!)
UIView.animateWithDuration(0.3, animations: { () -> Void in
if (offset > 0) {
self.view.frame.origin.y -= offset;
} else {
self.view.frame.origin.y = 0;
}
})
}
func keyboardWillHidden(notification: NSNotification) {
UIView.animateWithDuration(0.3, animations: { () -> Void in
self.view.frame.origin.y = 0;
})
}
}
extension Dialog : UITextFieldDelegate {
func textFieldDidBeginEditing(textField: UITextField) {
selectedEditText = textField
}
func textFieldShouldReturn(textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
func textFieldDidEndEditing(textField: UITextField) {
selectedEditText = nil
}
}
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