https://developers.weixin.qq.com/miniprogram/dev/api/network/mdns/wx.stopLocalServiceDiscovery.html 在IOS环境下 await wx.startLocalServiceDiscovery() await wx.stopLocalServiceDiscovery() await wx.startLocalServiceDiscovery() await wx.stopLocalServiceDiscovery() startLocalServiceDiscovery方法会报错 error scan task already exist