emoji表情与unicode编码互转的实现(JS,JAVA,C#)

Encoding.UTF32.GetBytes("😁") -> ["1", "f6", "1", "0"]

"😁".codePointAt(0).toString(16) -> 1f601

  byte[] bytes = "😀".getBytes("utf-32");
  System.out.println(getBytesCode(bytes));

 private static String getBytesCode(byte[] bytes) {
    String code = "";
    for (byte b : bytes) {
      code += "\\x" + Integer.toHexString(b & 0xff);
    }
    return code;
  }

Encoding.UTF8.GetBytes("😁") -> ["f0", "9f", "98", "81"]

encodeURIComponent("😁") -> %F0%9F%98%81

String.fromCodePoint('0x1f601')  utf-32

 String emojiName = "1f601"; //其实4个字节
  int emojiCode = Integer.valueOf(emojiName, 16);
  byte[] emojiBytes = int2bytes(emojiCode);
  String emojiChar = new String(emojiBytes, "utf-32");
  System.out.println(emojiChar);



  public static byte[] int2bytes(int num){
    byte[] result = new byte[4];
    result[0] = (byte)((num >>> 24) & 0xff);//说明一
    result[1] = (byte)((num >>> 16)& 0xff );
    result[2] = (byte)((num >>> 8) & 0xff );
    result[3] = (byte)((num >>> 0) & 0xff );
    return result;
  }

/// <summary>
/// <summary>
/// 字符串转Unicode
/// </summary>
/// <param name="source">源字符串</param>
/// <returns>Unicode编码后的字符串</returns>
public static string String2Unicode(string source)
{
 byte[] bytes = Encoding.Unicode.GetBytes(source);
 StringBuilder stringBuilder = new StringBuilder();
 for (int i = 0; i < bytes.Length; i += 2)
 {
 stringBuilder.AppendFormat("\\u{0}{1}", bytes[i + 1].ToString("x").PadLeft(2, '0'), bytes[i].ToString("x").PadLeft(2, '0'));
 }
 return stringBuilder.ToString();
}
 
/// <summary>
/// Unicode转字符串
/// </summary>
/// <param name="source">经过Unicode编码的字符串</param>
/// <returns>正常字符串</returns>
public static string Unicode2String(string source)
{
 return new Regex(@"\\u([0-9A-F]{4})", RegexOptions.IgnoreCase | RegexOptions.Compiled).Replace(
   source, x => string.Empty + Convert.ToChar(Convert.ToUInt16(x.Result("$1"), 16)));
}