typedef NS_ENUM(NSInteger, UIKeyboardType) {
    UIKeyboardTypeDefault,                // Default type for the current input method.
    UIKeyboardTypeASCIICapable,           // Displays a keyboard which can enter ASCII characters
    UIKeyboardTypeNumbersAndPunctuation,  // Numbers and assorted punctuation.
    UIKeyboardTypeURL,                    // A type optimized for URL entry (shows . / .com prominently).
    UIKeyboardTypeNumberPad,              // A number pad with locale-appropriate digits (0-9, ۰-۹, ०-९, etc.). 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).
    UIKeyboardTypeDecimalPad API_AVAILABLE(ios(4.1)),   // A number pad with a decimal point.
    UIKeyboardTypeTwitter API_AVAILABLE(ios(5.0)),      // A type optimized for twitter text entry (easy access to @ #)
    UIKeyboardTypeWebSearch API_AVAILABLE(ios(7.0)),    // A default keyboard type with URL-oriented addition (shows space . prominently).
    UIKeyboardTypeASCIICapableNumberPad API_AVAILABLE(ios(10.0)), // A number pad (0-9) that will always be ASCII digits.

    UIKeyboardTypeAlphabet = UIKeyboardTypeASCIICapable, // Deprecated

};

IB属性

UIKeyboardTypeDefault

• 默认样式
• 可以输入数字、字母、符号、emoji

• 可输入中文，以及中/英切换
  UIKeyboardTypeDefault

UIKeyboardTypeASCIICapable

• 只能输入数字、字母和符号，不能输入emoji和中文

• 适合输入密码等场景
  UIKeyboardTypeASCIICapable

UIKeyboardTypeNumbersAndPunctuation

• 只能输入数字、字母、符号和中文，不能输入emoji
  UIKeyboardTypeNumbersAndPunctuation

UIKeyboardTypeURL

• 可以输入数字、字母、符号、emoji和中文
• 提供URL常用的.com、.、/热键
  UIKeyboardTypeURL

UIKeyboardTypeNumberPad

• 只能输入0~9的纯数字
  UIKeyboardTypeNumberPad

UIKeyboardTypePhonePad

• 只能输入0~9的纯数字，和+ * #符号

• 适合输入电话号码场景
  UIKeyboardTypePhonePad

UIKeyboardTypeNamePhonePad

• 可以输入字母、数字、emoji和中文，不能输入特殊符号
• 能方便输入中/英文及数字

• 适用于联系人场景
  UIKeyboardTypeNamePhonePad

UIKeyboardTypeEmailAddress

• 可以输入字母、数字、符号、emoji和中文
• 提供Email常用的@、.热键

• 适合输入邮箱场景
  UIKeyboardTypeEmailAddress

UIKeyboardTypeDecimalPad

• 可以输入0~9纯数字及小数点.

• 适合含小数场景
  UIKeyboardTypeDecimalPad

UIKeyboardTypeTwitter

• 可以输入字母、数字、符号、emoji和中文
• 提供@、#热键
  UIKeyboardTypeTwitter

UIKeyboardTypeWebSearch

• 可以输入字母、数字、符号、emoji和中文
• 提供.、go热键

• 适合搜索场景
  UIKeyboardTypeWebSearch

UIKeyboardTypeASCIICapableNumberPad

• 只能输入0~9纯数字，iOS 10及以后才能使用

• 适合纯数字场景
  UIKeyboardTypeASCIICapableNumberPad

UIKeyboardTypeAlphabet - 已废弃