UIColor, UIFont, UIImage

UIColor:

//透明度

let transparentYellow = UIColor.yellowColor().colorWithAlphaComponent(0.5)

//要讓你的視圖透明，必須先給view設置屬性

var opaque = false

UIFont:

class func preferredFontForTextStyle(UIFontTextStyle) -> UIFont

UIFontTextStyle.Body

UIFontTextStyle.Body

UIFontTextStyle.Footnote

class func systemFontOfSize(pointSize: CGFloat) -> UIFont

class func boldSystemFontOfSize(pointSize: CGFloat) -> UIFont

UIImage:

let image: UIImage = ...

image.drawAtPoint(aCGPoint)

image.drawInRect(aCGRect)

image.drawAsPatternInRect(aCGRect)