UIKeyboardType 键盘弹出样式

typedef NS_ENUM(NSInteger, UIKeyboardType) {

    UIKeyboardTypeDefault,                // Default type for the current input method.

    UIKeyboardTypeASCIICapable,           // 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).

    UIKeyboardTypeDecimalPad NS_ENUM_AVAILABLE_IOS(4_1),  // A number pad with a decimal point.

    UIKeyboardTypeTwitter NS_ENUM_AVAILABLE_IOS(5_0),     // A type optimized for twitter text entry (easy access to @ #)

    UIKeyboardTypeWebSearch NS_ENUM_AVAILABLE_IOS(7_0),   // A default keyboard type with URL-oriented addition (shows space . prominently).

    UIKeyboardTypeAlphabet = UIKeyboardTypeASCIICapable,// Deprecated

};