func encodeEscapesURL(value:String) -> String {
let str:NSString = value
let originalString = str as CFStringRef
let charactersToBeEscaped = "!*'();:@&=+$,/?%#[]" as CFStringRef //":/?&=;+!@#$()',*" //转意符号
//let charactersToLeaveUnescaped = "[]." as CFStringRef //保留的符号
let result =
CFURLCreateStringByAddingPercentEscapes(kcfAllocatorDefault,originalString,nil,//charactersToLeaveUnescaped,
charactersToBeEscaped,CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding)) as NSString
return result as String
}