iOS 键盘类型UIKeyboardType
UIKeyboardTypeDefault:
UIKeyboardTypeASCIICapable:
UIKeyboardTypeNumbersAndPunctuation:
UIKeyboardTypeURL:
UIKeyboardTypeNumberPad:
UIKeyboardTypePhonePad:
UIKeyboardTypeNamePhonePad:
UIKeyboardTypeEmailAddress:
UIKeyboardTypeDecimalPad:
UIKeyboardTypeTwitter:
UIKeyboardTypeWebSearch:
UIKeyboardTypeAlphabet: