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)) }