未处理的异常:连接被拒绝-与颤振的连接

Question

当我试图将部署在Ganache本地块链上的智能契约与颤振web3dart包链接时，我会遇到这个错误。

注意:在android上进行测试(模拟器和物理设备都会产生相同的错误)

E/flutter ( 5780): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled
Exception: Connection refused
E/flutter ( 5780): #0      IOClient.send (package:http/src/io_client.dart:88:7)
E/flutter ( 5780): <asynchronous suspension>
E/flutter ( 5780): #1      BaseClient._sendUnstreamed (package:http/src/base_client.dart:93:32)
E/flutter ( 5780): <asynchronous suspension>
E/flutter ( 5780): #2      JsonRPC.call (package:web3dart/json_rpc.dart:49:22)
E/flutter ( 5780): <asynchronous suspension>
E/flutter ( 5780): #3      Web3Client._makeRPCCall (package:web3dart/src/core/client.dart:53:20)
E/flutter ( 5780): <asynchronous suspension>
E/flutter ( 5780): #4      ContractLinker.initialSetup (package:cupcake_eth2/contract_linking.dart:60:16)
E/flutter ( 5780): <asynchronous suspension>
E/flutter ( 5780): #5      ContractLinker.contractLinking (package:cupcake_eth2/contract_linking.dart:44:5)
E/flutter ( 5780): <asynchronous suspension>
E/flutter ( 5780): #6      ContractLinker.onInit (package:cupcake_eth2/contract_linking.dart:16:5)
E/flutter ( 5780): <asynchronous suspension>

以下是我的变量：

 final String _rpcUrl = "http://127.0.0.1:7545";
 final String _wsUrl = "ws://127.0.0.1:7545/";

truffle_config.js的相关部分：

networks: {
     development: {
      host: "127.0.0.1",
      port: 7545,           
      network_id: "*",       
     },
  },

我在跟踪这个教程

任何帮助都是非常感谢的。

Answer 1

添加

  final String _rpcUrl =
      Platform.isAndroid ? 'http://10.0.2.2:7545' : 'http://127.0.0.1:7545';
  final String _wsUrl =
      Platform.isAndroid ? 'http://10.0.2.2:7545' : 'ws://127.0.0.1:7545';

而不是

final String _rpcUrl = "http://127.0.0.1:7545";
final String _wsUrl = "ws://127.0.0.1:7545/";