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;