[Swift]NSString、NSData、Base64互转

####NSString、NSData互转####

let string &＃61; "Hello world"
//NSString 转 NSData
let utf8EncodeData:NSData! &＃61; string.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)
print("utf8EncodeData:\(utf8EncodeData)")// var bytes: COpaquePointer { get } 只读&＃xff0c;获取指向NSData对象内容的指针&＃xff0c;长度为0时返回nil
//NSData 转 NSString
let bytes &＃61; utf8EncodeData.bytes
let length &＃61; utf8EncodeData.length
let stringFromData &＃61; NSString(bytes: bytes, length: length, encoding: NSUTF8StringEncoding)
print("string from data: \(stringFromData)")


####Base64互转####

let string &＃61; "Hello world"// 将字符串进行UTF8编码成NSData
let utf8EncodeData:NSData! &＃61; string.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)// 将NSData进行base64编码
let base64EncodedString &＃61; utf8EncodeData.base64EncodedStringWithOptions(NSDataBase64EncodingOptions(rawValue: 0))
print("encodedString: \(base64EncodedString)")// 将base64字符串转换成NSData
let base64EncodedData &＃61; NSData(base64EncodedString:base64EncodedString,options:NSDataBase64DecodingOptions(rawValue: 0))
// 对NSData数据进行UTF8解码
let stringWithDecode &＃61; NSString(data: base64EncodedData!, encoding: NSUTF8StringEncoding)
print("base64String: \(stringWithDecode)")