emoji表情与unicode编码互转的实现(JS,JAVA,C#)

前几天刚好有需求要把emoji对应的Unicode编码转换成文字，比如1f601对应的这个笑脸😁，但没有找到C#的把1f601转换成文字的方法，用Encoding.Unicode怎么转换都不对，最后直接复制emoji字符，Visual Studio里面竟然直接显示出来了，那就直接用字符吧，都不用转换了，然后不了了之了。

今天搞Markdown编辑器，由于前面GFM的原因，又对编码进行测试，没查到什么靠谱资料，到时找到很多emoji和Unicode对照表，https://apps.timwhitlock.info/emoji/tables/unicode拿一个笑脸https://apps.timwhitlock.info/unicode/inspect/hex/1F601开刀~

1.表情字符转编码

【C#】

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

【js】

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

【java】

 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;
 }

UTF-32结果一致

【C#】

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

【js】

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

UTF-8结果一致

2.编码转表情字符

【js】

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

【java】 

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;
 }

c# 汉字和Unicode编码互相转换实例

/// <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)));
}

参考地址：

https://www.jianshu.com/p/8a416537deb3

https://blog.csdn.net/a19881029/article/details/13511729

https://apps.timwhitlock.info/emoji/tables/unicode

来源：https://www.cnblogs.com/hdwang/p/10309163.html