针对某个 UITextField 禁用第三方键盘

在日常开发中，可能某个 UITextField 只能输入数字，但是因为安装了第三方键盘（搜狗、百度等）会受到影响，需要禁用第三方键盘。

$\color{red}{禁用}$第三方键盘需要在 AppDelegate.m 中实现以下代码

- (BOOL)application:(UIApplication *)application
shouldAllowExtensionPointIdentifier:(NSString *)extensionPointIdentifier
{
    if ([extensionPointIdentifier isEqualToString:@"com.apple.keyboard-service"]) {
        return NO;
    }
    return YES;
}

这样就全局禁用了第三方键盘，下面针对某个 UITextField 进行禁用第三方键盘

对某个 UITextField 禁用第三方键盘

1. 给 UITextField 创建一个分类，然后在分类的 .h 文件中添加一个实例对象属性 yxc_usingSystemKeyboard 和一个类对象属性 yxc_globalUsingSystemKeyboard

   @property (nonatomic, assign) BOOL yxc_usingSystemKeyboard;  /**< 使用系统键盘 */
   @property (nonatomic, assign, class) BOOL yxc_globalUsingSystemKeyboard;   /**< 全局是否使用系统键盘，主动设置无效 */
   

2. 关联属性

   - (void)setYxc_usingSystemKeyboard:(BOOL)yxc_usingSystemKeyboard {
       
       objc_setAssociatedObject(self, @selector(yxc_usingSystemKeyboard), @(yxc_usingSystemKeyboard), OBJC_ASSOCIATION_ASSIGN);
   }
   
   - (BOOL)yxc_usingSystemKeyboard {
       
       NSNumber *yxc_usingSystemKeyboard = objc_getAssociatedObject(self, @selector(yxc_usingSystemKeyboard));
       return [yxc_usingSystemKeyboard boolValue];
   }
   
   + (void)setYxc_globalUsingSystemKeyboard:(BOOL)yxc_globalUsingSystemKeyboard {
       
       objc_setAssociatedObject(self, @selector(yxc_globalUsingSystemKeyboard), @(yxc_globalUsingSystemKeyboard), OBJC_ASSOCIATION_ASSIGN);
   }
   
   + (BOOL)yxc_globalUsingSystemKeyboard {
       
       NSNumber *yxc_globalUsingSystemKeyboard = objc_getAssociatedObject(self, @selector(yxc_globalUsingSystemKeyboard));
       return [yxc_globalUsingSystemKeyboard boolValue];
   }
   

3. 监听 UITextFieldTextDidBeginEditingNotification 和 UITextFieldTextDidEndEditingNotification 通知

    [[NSNotificationCenter defaultCenter] addObserver:self
                                            selector:@selector(textFieldDidBeginEdit:)
                                                name:UITextFieldTextDidBeginEditingNotification
                                              object:self];
   
   [[NSNotificationCenter defaultCenter] addObserver:self
                                            selector:@selector(textFieldDidEndEdit:)
                                                name:UITextFieldTextDidEndEditingNotification
                                              object:self];
   

4. 在监听到 UITextFieldTextDidBeginEditingNotification 和 UITextFieldTextDidEndEditingNotification 通知对 yxc_globalUsingSystemKeyboard 值修改

   - (void)textFieldDidBeginEdit:(NSNotification *)notification {
       
       UITextField.yxc_globalUsingSystemKeyboard = self.yxc_usingSystemKeyboard;
   }
   
   - (void)textFieldDidEndEdit:(NSNotification *)notification {
       
       UITextField.yxc_globalUsingSystemKeyboard = NO;
   }
   

5. AppDelegate 中 application:shouldAllowExtensionPointIdentifier: 方法中修改

   - (BOOL)application:(UIApplication *)application shouldAllowExtensionPointIdentifier:(NSString *)extensionPointIdentifier
    {
     if ([extensionPointIdentifier isEqualToString:@"com.apple.keyboard-service"]) {
         if (UITextField.yxc_globalUsingSystemKeyboard) {
             return NO;
         }
     }
     return YES;
   }
   

   通过对某个 UITextField 实例对象设置 yxc_usingSystemKeyboard 属性值为 YES 后就对某个 UITextField 禁用了第三方键盘.

   效果:

在这里，第一个输入框默认的样式，不禁用第三方键盘，第二个输入框禁用第三方键盘并且设置键盘样式为 UIKeyboardTypeNumberPad

代码