crypto: ^2.1.

import 'dart:convert';

import 'package:crypto/crypto.dart';

class SignServices{

  static getSign(){

    Map addressListAttr={

      "uid":'',

      "age":,

      "salt":'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' //私钥

    };

    List attrKeys=addressListAttr.keys.toList();

    attrKeys.sort();

    print(attrKeys);

    String str='';

    for(var i=;i<attrKeys.length;i++){

      str+="${attrKeys[i]}${addressListAttr[attrKeys[i]]}";

    }

    print(str);

    print(md5.convert(utf8.encode(str)));

  }

}