iosUITextField属性

@PRoperty UITextField *caption;caption = [[UITextField alloc] initWithFrame:CGRectMake(0,                                                            self.frame.size.height/2,                                                            self.frame.size.width,                                                            32)];    caption.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.5];    caption.textAlignment = NSTextAlignmentCenter;    caption.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;    caption.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;    caption.textColor = [UIColor whiteColor];    caption.keyboardAppearance = UIKeyboardAppearanceDark;    caption.alpha = 0;    caption.tintColor = [UIColor whiteColor];    caption.delegate = self;