iOS开发笔记--keyboard相关

最近一个项目有键盘相关的需求：自定义键盘与系统键盘切换。就将键盘相关的知识点顺了一遍。

一、UITextInputTraits 协议

该协议定义了一些与键盘输入相关的属性。所有支持键盘输入的对象都必须接受这个协议，目的是为了与文本输入管理系统正确地交互。

UITextField 和 UITextView ，UISearchBar都支持该协议。

 @protocol UITextInputTraits

 @optional

 @property(nonatomic) UITextAutocapitalizationType autocapitalizationType;
 //  定义输入文本的自动大写类型 default is UITextAutocapitalizationTypeSentences
 @property(nonatomic) UITextAutocorrectionType autocorrectionType;
  // 定义输入文本的自动更正类型 default is UITextAutocorrectionTypeDefault
 @property(nonatomic) UITextSpellCheckingType spellCheckingType NS_AVAILABLE_IOS(5_0);
 // 定义输入文本的拼写检查类型 default is UITextSpellCheckingTypeDefault;
 @property(nonatomic) UIKeyboardType keyboardType;
 // 定义键盘类型 default is UIKeyboardTypeDefault
 @property(nonatomic) UIKeyboardAppearance keyboardAppearance;
 // 定义键盘外貌类型 default is UIKeyboardAppearanceDefault
 @property(nonatomic) UIReturnKeyType returnKeyType;

 // 定义键盘returnKey的类型 default is UIReturnKeyDefault (See note under UIReturnKeyType enum)
 @property(nonatomic) BOOL enablesReturnKeyAutomatically;
 // default is NO (when YES, will automatically disable return key when text widget has zero-length contents, and will automatically enable when text widget has non-zero-length contents)
 @property(nonatomic,getter=isSecureTextEntry) BOOL secureTextEntry;
  // 输入文本是否加密 default is NO

 @end

 typedef NS_ENUM(NSInteger, UIKeyboardType) {
     UIKeyboardTypeDefault,                // Default type for the current input method.
     UIKeyboardTypeASCIICapable,
  // 字母键盘 Displays a keyboard which can enter ASCII characters, non-ASCII keyboards remain active
     UIKeyboardTypeNumbersAndPunctuation,  // Numbers and assorted punctuation.
     UIKeyboardTypeURL,                    // A type optimized for URL entry (shows . / .com prominently).
     UIKeyboardTypeNumberPad,              // A number pad (0-9). Suitable for PIN entry.
     UIKeyboardTypePhonePad,               // A phone pad (1-9, *, 0, #, with letters under the numbers).
     UIKeyboardTypeNamePhonePad,           // A type optimized for entering a person's name or phone number.
     UIKeyboardTypeEmailAddress,           // A type optimized for multiple email address entry (shows space @ . prominently).
 #if __IPHONE_4_1 <= __IPHONE_OS_VERSION_MAX_ALLOWED
     UIKeyboardTypeDecimalPad,             // A number pad with a decimal point.
 #endif
 #if __IPHONE_5_0 <= __IPHONE_OS_VERSION_MAX_ALLOWED
     UIKeyboardTypeTwitter,                // A type optimized for twitter text entry (easy access to @ #)
 #endif

     UIKeyboardTypeAlphabet = UIKeyboardTypeASCIICapable, // Deprecated

 };

这个属性决定了在输入文本中，是否支持拼写检查。

二、定制键盘

 @interface UIResponder (UIResponderInputViewAdditions)

 // Called and presented when object becomes first responder.  Goes up the responder chain.
 @property (readonly, retain) UIView *inputView NS_AVAILABLE_IOS(3_2);
 //键盘视图，定制的键盘视图要赋值给该属性
 @property (readonly, retain) UIView *inputAccessoryView NS_AVAILABLE_IOS(3_2);
 //键盘辅助视图，即位于键盘视图上面一些额外的辅助性视图，可在上添加辅助功能键

 // If called while object is first responder, reloads inputView and inputAccessoryView.  Otherwise ignored.
 - (void)reloadInputViews NS_AVAILABLE_IOS(3_2);

 @end

UITextField 和 UITextView 都提供了以上方法。

如上图所示，绿色视图为 inputAccessoryView。下面的是定制的键盘视图

示例代码如下

  -  (void)viewDidLoad
 {
         [super viewDidLoad];

         self.numberTextField = [[UITextField alloc] initWithFrame:CGRectMake(20, 120, 280, 80)];
     self.numberTextField.backgroundColor = [UIColor darkGrayColor];
     self.numberTextField.delegate = self;
     self.numberTextField.keyboardType = UIKeyboardTypeNamePhonePad;

         self.numberTextField.autocapitalizationType = UITextAutocapitalizationTypeNone;
     self.numberTextField.autocorrectionType = UITextAutocorrectionTypeNo;
     self.numberTextField.spellCheckingType = UITextSpellCheckingTypeNo;
     self.numberTextField.returnKeyType = UIReturnKeySearch;

         _inputView = [[AZStockKeyboardView alloc] initWithFrame:CGRectMake(0, 0, rect.size.width, 216)];
     _inputView.delegate = self;
     self.numberTextField.inputView = _inputView;
     UIView *accessoryView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
     accessoryView.backgroundColor = [UIColor greenColor];
     self.numberTextField.inputAccessoryView = accessoryView;
     [self.view addSubview:self.numberTextField];
 }

切换系统键盘

 - (void)customedKeyboardDidChange
 {
     self.numberTextField.inputView = nil;
     [self.numberTextField reloadInputViews];
 }

系统键盘切换定制键盘

 - (void)systemKeyboardDidChange
 {
     self.numberTextField.inputView = _inputView;
     [self.numberTextField reloadInputViews];
 }

给定制的键盘添加系统键盘按键声音

1.定制键盘视图要继承UIView，接受 UIInputViewAudioFeedback 协议，并实现协议方法

 @interface AZStockKeyboardView : UIView
 {

 }

 #pragma mark UIInputViewAudioFeedback protocol methods

 - (BOOL)enableInputClicksWhenVisible
 {
     return YES;
 }

2.在定制的键盘的按键响应的方法中，调用 [[UIDevice currentDevice] playInputClick]

 - (void)numberButtonClicked:(id)sender
 {
     [[UIDevice currentDevice] playInputClick];
 }

三、改造系统键盘

由于需要定制键盘和系统键盘互相切换，就需要将系统键盘的切换键盘的按键响应我们自己的切换键盘方法。

Apple官方并没有提供这种方法，目前可行的做法是将该按键用我们自己的创建的按键将其覆盖。

UITextEffectsWindow       //键盘所在window

UIPeripheralHostView      //键盘视图所在的父视图  定制的键盘视图，辅助视图都放在这个视图上面

UIKeyboardAutomatic      //键盘视图

UIKeyboardImpl               //自己按英文的意思理解的，键盘的实现视图

UIKeyboardLayoutStar     //自己按英文的意思理解的，键盘的布局视图

UIKBKeyplaneView          //

UIKBKeyView                   //根据description判断，是键盘的功能性按键的视图（除字母，数字之外，类似删除键，空格键等）

以上视图都有层级关系，从上到下，上面的视图是下面视图的父视图

完成覆盖按键的任务，需要获取 UIKeyboardAutomatic 视图，然后把定制的切换按键添加到该视图上

获取系统键盘视图

 - (UIView *)getSystemKeyboardView
 {
     UIView *returnView = nil;

     UIWindow *keyboardWindow = nil;
     for (UIWindow *window in [[UIApplication sharedApplication] windows])
     {
         if (![NSStringFromClass([window class]) isEqualToString:NSStringFromClass([UIWindow class])])
         {
             keyboardWindow = window;
             break;
         }
     }
     if (keyboardWindow == nil)
         return nil;

     for (UIView *firstView in [keyboardWindow subviews])
     {
         if ([[firstView description] hasPrefix:@"
         {
             for (UIView *secondView in [firstView subviews])
             {
                 if ([[secondView description] hasPrefix:@"
                 {
                     returnView = secondView;
                 }
             }
         }
     }

     return returnView;
 }

监听键盘事件

 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
 ificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil];

向键盘视图上覆盖按键

 - (void)keyboardDidShow:(id)notification
 {
     _keyboardDefaultView = [self getSystemKeyboardView];
     if (_keyboardDefaultView)
     {
         _switchNumButton = [UIButton buttonWithType:UIButtonTypeCustom];
         [_switchNumButton setTitle:@"123" forState:UIControlStateNormal];
         [_switchNumButton setBackgroundImage:[UIImage imageNamed:@"num.png"] forState:UIControlStateNormal];
         _switchNumButton.frame = CGRectMake(1, 173, 78, 42);
         [_switchNumButton addTarget:self action:@selector(changeCutomeButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
         [_keyboardDefaultView addSubview:_switchNumButton];
     }
 }

效果如下：

注意：由于所有系统键盘都是所有程序共享的，所以在当前界面消失前，或者其他类型的输入视图调用键盘前，要将我们自己定制的按键移除。

否则，从其他应用调用该类型键盘，都可以看到我们定制的按键。

同时也应该在调用键盘前，即键盘弹出时，在用我们定制的按键覆盖之前加限定条件

 - (void)keyboardDidShow:(id)notification
 {
     _keyboardDefaultView = [self getSystemKeyboardView];
     if (_keyboardDefaultView && [_numberTextField isFirstResponder])
     {
         _switchNumButton = [UIButton buttonWithType:UIButtonTypeCustom];
         [_switchNumButton setTitle:@"123" forState:UIControlStateNormal];
         [_switchNumButton setBackgroundImage:[UIImage imageNamed:@"num.png"] forState:UIControlStateNormal];
         _switchNumButton.frame = CGRectMake(1, 173, 78, 42);
         [_switchNumButton addTarget:self action:@selector(changeCutomeButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
         [_keyboardDefaultView addSubview:_switchNumButton];
     }
     else
     {
         if (_switchNumButton) {
             [_switchNumButton removeFromSuperview];
         }
     }