Swift String to UIColor(16进制字符串转颜色值)

func colorWithHexString (hex:String) -> UIColor {
	var cString:String = hex.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()).uppercaseString
	if (cString.hasPrefix("#")) {
	cString = cString.substringFromIndex(1)
	}
	if (countElements(cString) != 6) {
	return UIColor.grayColor()
	}
	var rString = cString.substringToIndex(2)
	var gString = cString.substringFromIndex(2).substringToIndex(2)
	var bString = cString.substringFromIndex(4).substringToIndex(2)
	var r:CUnsignedInt = 0, g:CUnsignedInt = 0, b:CUnsignedInt = 0;
	NSScanner.scannerWithString(rString).scanHexInt(&r)
	NSScanner.scannerWithString(gString).scanHexInt(&g)
	NSScanner.scannerWithString(bString).scanHexInt(&b)
	return UIColor(red: Float(r) / 255.0, green: Float(g) / 255.0, blue: Float(b) / 255.0, alpha: Float(1))
	}