Swift 解码和编码字符串答案

【问题标题】：Swift decode and encode stringSwift 解码和编码字符串
【发布时间】：2016-10-09 00:35:50
【问题描述】：

我正在尝试使用 Swift 对字符串和数据进行编码和解码。在Java中它相对简单，我可以使用CharsetCharsetDecoderCharsetEncoder，就像下面的sn-p代码一样。我认为解决方案是使用String.Encoding，但如何使用？

public static void Test() throws CharacterCodingException {
    Charset charset = Charset.forName("UTF-8");
    CharsetDecoder chdecoder = charset.newDecoder();
    CharsetEncoder chencoder = charset.newEncoder();
    String s = "Encode and Decode Example.";
    if(!chencoder.canEncode((char) 9)) return;//not here but i need this method
    ByteBuffer byteBuffer= ByteBuffer.wrap(s.getBytes());
    CharBuffer charBuffer = chdecoder.decode(byteBuffer);
    ByteBuffer newByteBuff = chencoder.encode(charBuffer);
    while(newByteBuff.hasRemaining()){
        char ch = (char) newByteBuff.get();
        System.out.print(ch);
    }
    newByteBuff.clear();
}

【问题讨论】：

标签： java swift string character-encoding char

【解决方案1】：

let str = "iOS Developer Tips encoded in Base64"
println("Original: \(str)")
let utf8str = str.dataUsingEncoding(NSUTF8StringEncoding)
if let base64Encoded =      utf8str?.base64EncodedStringWithOptions(NSDataBase64EncodingOptions(rawValue: 0)) 
{
println("Encoded:  \(base64Encoded)")
if let base64Decoded = NSData(base64EncodedString: base64Encoded, options:   NSDataBase64DecodingOptions(rawValue: 0))
                      .map({ NSString(data: $0, encoding: NSUTF8StringEncoding) })
{
    // Convert back to a string
    println("Decoded:  \(base64Decoded)")
}
}

【讨论】：

【解决方案2】：

Swift3 答案

let str = "iOS Developer Tips encoded in Base64"
print("Original: \(str)")
let utf8str = str.data(using: String.Encoding.utf8)
if let base64Encoded = utf8str?.base64EncodedString(options:Data.Base64EncodingOptions(rawValue: UInt(0)))
{
    print("Encoded:  \(base64Encoded)")
    if let base64Decoded = NSData(base64Encoded: base64Encoded, options:NSData.Base64DecodingOptions(rawValue: UInt(1)))
        .map({ NSString(data: $0 as Data, encoding: String.Encoding.utf8.rawValue) })
    {
        // Convert back to a string
        print("Decoded:  \(base64Decoded)")
    }
}

【讨论】：