Flutter MQTT 一直断开重连的

使用的是这个库

image.png
一开始只有一个人开发，一直没有发现这个问题，后面测试的时候
多个人登录app开始测试，发现MQTT一直断开重连，找了很久没有找到问题
最终在这篇文章找到答案 https://stackoverflow.com/questions/73047572/flutter-mqtt-disconnect-immediately-after-connecting

修改之前

final MqttConnectMessage connMess = MqttConnectMessage()
        .withClientIdentifier('test')
        .startClean()
        .authenticateAs(userName, password)
        // .withWillTopic('willtopic')
        // .withWillMessage('Will message')
        .withWillQos(MqttQos.atLeastOnce);
    _client.connectionMessage = connMess;

修改后，withClientIdentifier其实可以不设置，如果要设置，一定是唯一的，我这里使用随机时间戳来实现

final MqttConnectMessage connMess = MqttConnectMessage()
        .withClientIdentifier('test ${DateTime.now().millisecondsSinceEpoch}')
        .startClean()
        .authenticateAs(userName, password)
        // .withWillTopic('willtopic')
        // .withWillMessage('Will message')
        .withWillQos(MqttQos.atLeastOnce);
    _client.connectionMessage = connMess;