Flutter地址查询插件at_lookup的使用

一、简介

at_lookup库是atProtocol动词的低级直接实现。该库提供了与二级服务器交互以执行命令（如scan、update、lookup、llookup、plookup等）的接口。

• 版本信息：
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二、安装配置

1. 添加依赖

在pubspec.yaml文件中添加以下内容：

dependencies:
  at_lookup: ^3.0.5

然后在终端运行：

pub get

2. 导入库

在Dart代码中导入库：

import 'package:at_lookup/at_lookup.dart';

三、基本用法

1. 创建AtLookup实例

要获取at_lookup的实例，可以按照以下方式创建：

AtLookUp atLookUp = AtLookupImpl(
  '@alice', // 用户名
  'root.atsign.com', // 二级服务器地址
  64, // 端口号
  privateKey: 'privateKey', // 私钥
  cramSecret: 'cramSecret', // CRAM密钥
);

2. 示例：操作键值对

(1) 更新键值

var updateVerbBuilder = UpdateVerbBuilder()
  ..atKey = 'phone' // 键名
  ..sharedBy = '@alice' // 分享者
  ..sharedWith = '@bob' // 接收者
  ..value = '+1 889 886 7879'; // 值

// 发送更新命令到二级服务器，并同步
var updateResult = await atLookUp.executeVerb(updateVerbBuilder, sync: true);
print('Update result: $updateResult');

(2) 查询键值

var lookupVerbBuilder = LookupVerbBuilder()
  ..atKey = 'phone'
  ..sharedBy = '@bob'
  ..auth = true;

// 发送查询命令到二级服务器
var lookupResult = await atLookUp.executeVerb(lookupVerbBuilder);
print('Lookup result: $lookupResult');

(3) 获取所有键

var scanVerbBuilder = ScanVerbBuilder();
var scanResult = await atLookUp.executeVerb(scanVerbBuilder);
print('Scan result: $scanResult');

(4) 删除键

var deleteVerbBuilder = DeleteVerbBuilder()
  ..sharedWith = '@bob'
  ..atKey = 'phone'
  ..sharedBy = '@alice';

// 发送删除命令到二级服务器并同步
var deleteResult = await atLookUp.executeVerb(deleteVerbBuilder, sync: true);
print('Delete result: $deleteResult');

四、完整示例Demo

下面是一个完整的Flutter应用示例，展示了如何使用at_lookup库进行简单的键值操作。

import 'package:flutter/material.dart';
import 'package:at_lookup/at_lookup.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'AtLookup Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'AtLookup Demo'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  late AtLookUp atLookUp;
  String resultText = '';

  @override
  void initState() {
    super.initState();
    initAtLookup();
  }

  Future<void> initAtLookup() async {
    atLookUp = AtLookupImpl(
      '@alice',
      'root.atsign.com',
      64,
      privateKey: 'privateKey',
      cramSecret: 'cramSecret',
    );
  }

  Future<void> performOperation(String operation) async {
    try {
      switch (operation) {
        case 'update':
          var updateVerbBuilder = UpdateVerbBuilder()
            ..atKey = 'phone'
            ..sharedBy = '@alice'
            ..sharedWith = '@bob'
            ..value = '+1 889 886 7879';
          var updateResult = await atLookUp.executeVerb(updateVerbBuilder, sync: true);
          setState(() {
            resultText = 'Update result: $updateResult';
          });
          break;
        case 'lookup':
          var lookupVerbBuilder = LookupVerbBuilder()
            ..atKey = 'phone'
            ..sharedBy = '@bob'
            ..auth = true;
          var lookupResult = await atLookUp.executeVerb(lookupVerbBuilder);
          setState(() {
            resultText = 'Lookup result: $lookupResult';
          });
          break;
        case 'scan':
          var scanVerbBuilder = ScanVerbBuilder();
          var scanResult = await atLookUp.executeVerb(scanVerbBuilder);
          setState(() {
            resultText = 'Scan result: $scanResult';
          });
          break;
        case 'delete':
          var deleteVerbBuilder = DeleteVerbBuilder()
            ..sharedWith = '@bob'
            ..atKey = 'phone'
            ..sharedBy = '@alice';
          var deleteResult = await atLookUp.executeVerb(deleteVerbBuilder, sync: true);
          setState(() {
            resultText = 'Delete result: $deleteResult';
          });
          break;
      }
    } catch (e) {
      setState(() {
        resultText = 'Error: $e';
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            ElevatedButton(
              onPressed: () => performOperation('update'),
              child: Text('Update Key'),
            ),
            ElevatedButton(
              onPressed: () => performOperation('lookup'),
              child: Text('Lookup Key'),
            ),
            ElevatedButton(
              onPressed: () => performOperation('scan'),
              child: Text('Scan Keys'),
            ),
            ElevatedButton(
              onPressed: () => performOperation('delete'),
              child: Text('Delete Key'),
            ),
            SizedBox(height: 20),
            Text(resultText),
          ],
        ),
      ),
    );
  }
}

以上就是关于Flutter地址查询插件at_lookup的基本介绍和使用方法，希望对您有所帮助！