（收藏）在 iPhone/iPad 中随意修改数字键盘按钮

一、起因

iPhone 的键盘，特别是数字键盘，往往不能满足程序的输入需要。最典型的例子就是在数字键盘上添加一个“.”，用来输入小数点。安装 iPhone SDK 官方的观点，如果要使用小数点键盘，那只好使用数字和符号键盘，但那样没个按键很小，且不需要的按键太多。


二、现有方案

针对这种情况，最早的解决方案，请参考这里：http://www.cnblogs.com/mac_arthur/archive/2010/05/18/1738363.html。使用的是 以下代码来检测一个 Notification。

引用

[[NSNotificationCenter defaultCenter] addObserver:self 
                                          selector:@selector(addCustomKeyBoardButton)
                                                 name:UIKeyboardWillShowNotification
                                               object:nil];

这种方法，在 iOS 4.0 后失效了，原因有两个，一是UIKeyboardWillShowNotification的时候，键盘根本没有创建出来;另外，Class Name 也被外包了一层，叫做UIPeripheralHostView。

于是又有了一种改进的方案，请看这里：http://www.neoos.ch/news/46-development/54-uikeyboardtypenumberpad-and-the-missing-return-key。主要的改进是在UIKeyboardDidShowNotification的通知消息中来修改键盘。但正如作者所说，这里有个不完美的情况，只能等键盘动画显示完成之后，才能添加显示我们的东西，视觉效果不好。

三、改进方案

经过试验，找到一个比较完美的方案：在 UITextField 的becomeFirstResponder和resignFirstResponder中修改键盘。

定以一个类，假如叫做 KBCustomTextField : UITextField，在这个类中加入一下代码：

引用

//
- (BOOL)becomeFirstResponder
{
  BOOL ret = [super becomeFirstResponder];
  [self modifyKeyView:@"NumberPad-Empty" display:@"." represent:@"." interaction:@"String"];
  return ret;
}

//
- (BOOL)resignFirstResponder
{
  BOOL ret = [super resignFirstResponder];
  [self modifyKeyView:@"NumberPad-Empty" display:nil represent:nil interaction:@"None"];
  return ret;
}

modifyKeyView 的实现可以参看附件。我使用的是循环查找UIKBKeyView类，这是Apple 的 Private API（私有API的声明可以在这里找：http://github.com/kennytm/iphone-private-frameworks/tree/master/UIKit/），不确信能否通过 App Store 的审核：）

更近一步地，我完善了一下 KBCustomTextField，通过这个类，非常方便地就可以做到自定义输入键盘：

下载文件 (已下载 51 次)

点击这里下载文件: KBCustom.zip

1. 使用小数点和数字键盘：非常简单，只要在 IB 中把 UITextField 的类改成KBCustomTextField，就OK了，不用一行代码，效果如下图：


2. 在键盘的按键上添加一个文字按钮（并指定处理动作）：设置KBCustomTextField.kbDelegate，实现这两个函数即可：

引用

// [Yonsm] Handle keyboard show
- (void)keyboardShow:(KBCustomTextField *)sender
{
  [sender addCustomButton:@"NumberPad-Empty" title:@"DONE" target:self action:@selector(onButton:)];
}

// [Yonsm] Handle keyboard hide
- (void)keyboardHide:(KBCustomTextField *)sender
{
  [sender delCustomButton:@"NumberPad-Empty"];
}

3. 更近一步地，这两个 Delegate 函数中，你只要通过 name 来查找到想要修改的 UIKBKeyView，就可以随便修改它。name 可以通过 KBCustomTextField 的#define _LOG_KEY_VIEW来列出所有的按键名称。name 为 nil 则找任何的 UIKBKeyView（可以用他的 .superview 来找到整个键盘View，做更多的处理）。



下面是 iPhone 数字键盘的前面10个按键（后面忘了打出来了：）

引用

Found View: UIPeripheralHostView
Found View: UIKeyboardAutomatic
Found View: UIKeyboardImpl
Found View: UIKeyboardLayoutStar
Found View: UIKBKeyplaneView
Found View: UIKBKeyView
  name=NumberPad-1  representedString=1  displayString=1  displayType=NumberPad  interactionType=String  displayRowHint=Row1
Found View: UIKBKeyView
  name=NumberPad-2  representedString=2  displayString=2/ABC  displayType=NumberPad  interactionType=String  displayRowHint=Row1
Found View: UIKBKeyView
  name=NumberPad-3  representedString=3  displayString=3/DEF  displayType=NumberPad  interactionType=String  displayRowHint=Row1
Found View: UIKBKeyView
  name=NumberPad-4  representedString=4  displayString=4/GHI  displayType=NumberPad  interactionType=String  displayRowHint=Row2
Found View: UIKBKeyView
  name=NumberPad-6  representedString=6  displayString=6/MNO  displayType=NumberPad  interactionType=String  displayRowHint=Row2
Found View: UIKBKeyView
  name=NumberPad-7  representedString=7  displayString=7/PQRS  displayType=NumberPad  interactionType=String  displayRowHint=Row3
Found View: UIKBKeyView
  name=NumberPad-8  representedString=8  displayString=8/TUV  displayType=NumberPad  interactionType=String  displayRowHint=Row3
Found View: UIKBKeyView
  name=NumberPad-9  representedString=9  displayString=9/WXYZ  displayType=NumberPad  interactionType=String  displayRowHint=Row3
Found View: UIKBKeyView
  name=NumberPad-Empty  representedString=  displayString=  displayType=NumberPad  interactionType=None  displayRowHint=Row4

代码对 iPad 也有效，当然 Key Name 和  Type 不一样，下面是 iPad 数字键盘的Log：

引用

Found View: UIPeripheralHostView
Found View: UIKeyboardAutomatic
Found View: UIKeyboardImpl
Found View: UIKeyboardLayoutStar
Found View: UIKBKeyplaneView
Found View: UIKBKeyView
  name=Digit-1  representedString=1  displayString=1  displayType=String  interactionType=String-Popup  displayRowHint=Row1
Found View: UIKBKeyView
  name=Digit-2  representedString=2  displayString=2  displayType=String  interactionType=String-Popup  displayRowHint=Row1
Found View: UIKBKeyView
  name=Digit-3  representedString=3  displayString=3  displayType=String  interactionType=String-Popup  displayRowHint=Row1
Found View: UIKBKeyView
  name=Digit-4  representedString=4  displayString=4  displayType=String  interactionType=String-Popup  displayRowHint=Row1
Found View: UIKBKeyView
  name=Digit-5  representedString=5  displayString=5  displayType=String  interactionType=String-Popup  displayRowHint=Row1
Found View: UIKBKeyView
  name=Digit-6  representedString=6  displayString=6  displayType=String  interactionType=String-Popup  displayRowHint=Row1
Found View: UIKBKeyView
  name=Digit-7  representedString=7  displayString=7  displayType=String  interactionType=String-Popup  displayRowHint=Row1
Found View: UIKBKeyView
  name=Digit-8  representedString=8  displayString=8  displayType=String  interactionType=String-Popup  displayRowHint=Row1
Found View: UIKBKeyView
  name=Digit-9  representedString=9  displayString=9  displayType=String  interactionType=String-Popup  displayRowHint=Row1
Found View: UIKBKeyView
  name=Digit-0  representedString=0  displayString=0  displayType=String  interactionType=String-Popup  displayRowHint=Row1
Found View: UIKBKeyView
  name=Hyphen-Minus  representedString=-  displayString=-  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Solidus  representedString=/  displayString=/  displayType=String  interactionType=String-Popup  displayRowHint=Row2
Found View: UIKBKeyView
  name=Colon  representedString=:  displayString=:  displayType=String  interactionType=String-Popup  displayRowHint=Row2
Found View: UIKBKeyView
  name=Semicolon  representedString=;  displayString=;  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Left-Parenthesis  representedString=(  displayString=(  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Right-Parenthesis  representedString=)  displayString=)  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Primary-Currency-Sign  representedString=$  displayString=$  displayType=DynamicString  interactionType=String-Popup
Found View: UIKBKeyView
  name=Ampersand  representedString=&  displayString=&  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Commercial-At  representedString=@  displayString=@  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Full-Stop  representedString=.  displayString=.  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Comma  representedString=,  displayString=,  displayType=String  interactionType=String-Popup  displayRowHint=Row3
Found View: UIKBKeyView
  name=Question-Mark  representedString=?  displayString=?  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Exclamation-Mark  representedString=!  displayString=!  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Apostrophe  representedString='  displayString=’  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Quotation-Mark  representedString="  displayString=”  displayType=String  interactionType=String-Popup  
Found View: UIKBKeyView
  name=Delete-Key  representedString=Delete  displayString=delete  displayType=Delete  interactionType=Delete  
Found View: UIKBKeyView
  name=Return-Key  representedString=
interactionType=Return  displayRowHint=Row2
Found View: UIKBKeyView
  name=Undo-Key  representedString=undo  displayString=undo  displayType=Command  interactionType=Undo  displayRowHint=Row3
Found View: UIKBKeyView
  name=More-Key  representedString=More  displayString=more  displayType=More  interactionType=More  displayRowHint=Row4
Found View: UIKBKeyView
  name=Unlabeled-Space-Key  representedString=   displayString=  displayType=Space  interactionType=Space  
Found View: UIKBKeyView
  name=More-Key  representedString=More  displayString=more  displayType=More  interactionType=More  displayRowHint=Row4
Found View: UIKBKeyView
  name=Dismiss-Key  representedString=Dismiss  displayString=Dismiss  displayType=Dismiss  interactionType=Dismiss  
Found View: UIKBKeyView
  name=Shift-Key  representedString=Shift  displayString=shift  displayType=Shift  interactionType=Shift  displayRowHint=Row3
Found View: UIKBKeyView
  name=Shift-Key  representedString=Shift  displayString=shift  displayType=Shift  interactionType=Shift  displayRowHint=Row3