Unity Editor中文字体去重

[MenuItem("Tools/GenerateZhCharacter")]
public static void GenerateZhCharacter()
{
    var dataPath = Application.dataPath;
    var path = Path.Combine(dataPath, "Resources/zh_gene.txt");
    List<string> exists = new List<string>();
    StringBuilder builder = new StringBuilder();
    builder.Append("!#$%&'()*,-./0123456789:;<=>?ABCDEFGHIJKLMNOPQRSTUVWXYZ[]^_abcdefghijklmnopqrstuvwxyz{}~ ·ÀÂÄÇÈÉÊÎÔÖÜßàâäçèéêîïôöùûüŒœ—‘’“”…、。《》！（），：？ 繁文");
    var localizationAsset = Resources.Load<LanguageSourceAsset>("I2Languages");//此处为I2插件的Asset，自行修改为自己使用的插件或者文本文件然后遍历
    Regex regex = new Regex(@"^[\u4E00-\u9FA5]{0,}$");
    foreach (var iTerm in localizationAsset.mSource.mTerms)
    {                
        Debug.Log(iTerm.Languages[4]);
        //繁体
        for (int i = 0; i < iTerm.Languages[4].Length; i++)
        {
            var item = iTerm.Languages[4][i].ToString();
            if (regex.IsMatch(item) && !exists.Contains(item))
            {
                builder.Append(item);
                exists.Add(item);
            }
        }
    }
    foreach (var iTerm in localizationAsset.mSource.mTerms)
    {                
        Debug.Log(iTerm.Languages[3]);
        //简体
        for (int i = 0; i < iTerm.Languages[3].Length; i++)
        {
            var item = iTerm.Languages[3][i].ToString();
            if (regex.IsMatch(item) && !exists.Contains(item))
            {
                builder.Append(item);
                exists.Add(item);
            }
        }
    }
    
    File.WriteAllText(path,builder.ToString());
    AssetDatabase.Refresh();
    Debug.Log("最终的字符串：" + builder.ToString());
}