connect method
连接设备 返回设备对象
Implementation
Device connect({connectTimeout = 0}) {
Device? device = FlutterBlueElves.instance._deviceCache[_id];
if (device == null) {
///cache里面没有代表之前没有连接过,所以可以用扫描对象连接,除非将device.destroy()
device = Device._(_id, 0); //创建设备对象
FlutterBlueElves.instance._deviceCache[_id] = device; //将device加入到cache中
device._state = DeviceState.connecting; //将对象状态置为连接中
FlutterBlueElves.instance._channel.invokeMethod('connect', {
"id": _id,
"timeout": Platform.isAndroid ? connectTimeout : connectTimeout ~/ 1000,
"isFromScan": false,
"rssi": 0
}); //去连接
} else {
///如果是同一个设备就不需要再新建device对象,直接用已有device对象连接即可
device.connect(connectTimeout: connectTimeout);
}
return device;
}