start method

void start()

启动Socket ping reconnect

Implementation

void start() {

  if(isFirst) {
    isFirst = false;
    //////////////保活机制////////////////////////
    //监听生命周期
    WidgetsBinding.instance.addObserver(this);
    //定时器
    _initIMCheckTimer();
    _initNtCheckTimer();
  }
  connectToServer();
}