Convert Hexadecimal string to ascii string in Flutter/Dart

Question

I need help because I'm a DART beginner. I get a Json in the following format:

{"RETORNO":"0","OPERACAO":"PESQUISA_DADOS","UF":"RJ","MUNICIPIO":"","CODIGO_BENEFICIO":"7","BAIRRO":"","PALAVRA_CHAVE":"",
"REG":[
{"NOME":"3247204544554341c7c34f20452043554c5455524120464953494341204c5444412e","NOME_ABREVIADO":"435552564553202d2043454e54524f20505241c741204d415541","TIPO_BENEFICIO":"4553504f52544553","ENDERECO":"4156454e4944412052494f204252414e434f2c203433202f20534f4252454c4f4a41202d20434550203230303930303033202d2052494f204445204a414e4549524f202d20524a","TELEFONES":"2832312920203232303330333836","URL_SITE":"7777772e6375727665732e636f6d2e6272"}
]
}

When retrieving the information decode using the instruction below,

_nome = dados["NOME"]==null ? " " : ascii.decode(hex.decode(dados["NOME"])).toString();

I get the following error:

Error: I/flutter ( 7525): FormatException: Invalid value in input: 199

3247204544554341c7c34f20452043554c5455524120464953494341204c5444412e 2G EDUCAÇÃO E CULTURA FISICA LTDA.

The Hex format string has special characters (ÇÃ) which causes the error. Do I need to convert to UTF8 format? How should I do? Can anyone help?

Solution

ASCII doesn't support brazilian characters such as ç, á and etc. You have to use Unicode.

Dart String is natively a Unicode UTF-16, so unless you need ASCII for some reason, just use the Dart String and you will be fine.

Comments

[Gilberto Lopes Inacio]

Perfect! Replaces with _name = data ["NAME"] == null? "": String.fromCharCodes (hex.decode (data ["NAME"])); And it worked perfectly. Thanks!!!

[Michel Feinstein]

My pleasure. If this answered your question, don't forget to mark it as "Answered", clicking on the Check mark below the vote numbers.

[Ber]

Your answer would be much more useful if you included actual sample code. Thanks

[Michel Feinstein]

The sample code is the first comment on this answer.