微信小程序,wx.writeBLECharacteristicValue返回成功,但是蓝牙打印不了

Question

问题描述

问题出现的环境背景及自己尝试过哪些方法

相关代码

// 请把代码文本粘贴到下方（请勿用图片代替代码）
//index.js
//获取应用实例
const app = getApp()

Page({
data: {

userInfo: {},
hasUserInfo: false,
canIUse: wx.canIUse('button.open-type.getUserInfo'),
devices: [],
deviceId: '',
services: [],
serviceId: '',
characteristicId: '',
characteristicIdNotify: '',
characteristicIdRead: '',

},
onLoad() {

// wx.showModal({
//   title: '提示',
//   content: '请检查手机蓝牙是否打开',
//   success: function (res) {
//     that.setData({
//       isbluetoothready: false,
//       searchingstatus: false
//     })
//   }
// })

},
/**

• @description 开启蓝牙适配器

*/
openBlue() {

let _this = this
wx.openBluetoothAdapter({
  success(res) {
    console.log('开启适配器：', res)

    // 搜索蓝牙设备
    _this.discoverDevices()

  }
})

},
closeBlue() {

wx.closeBluetoothAdapter({
  success(res) {
    console.log('关闭适配器: ', res)
  }
})

},
/**

• @description 搜索蓝牙设备

*/
discoverDevices() {

let _this = this
wx.startBluetoothDevicesDiscovery({
  success(res) {
    console.log('搜索完成', res)

    setTimeout(() => {
      _this.getDevices()
      setTimeout(() => {
        _this.foundDevices()
      }, 500)
    }, 500)
  }
})

},
/**

• @description 搜索新的蓝牙设备

*/
foundDevices() {

let _this = this
wx.onBluetoothDeviceFound(function (devices) {
  console.log('检测到新设备：', devices)

  // 检测到新设备后，更新设备列表，供选择
  _this.data.devices.push(devices.devices[0])
  _this.setData({
    devices: _this.data.devices
  })
})

},
/**

• @description 获取可连接的蓝牙设备

*/
getDevices() {

let _this = this
wx.getBluetoothDevices({
  success: function (res) {
    if (res.devices[0]) {
      console.log('获取设备:', res)
      _this.setData({
        devices: res.devices
      })
    }
  }
})

},
chooseDevice(e) {

let _this = this

// 储存 deviceId
_this.data.deviceId = e.currentTarget.dataset.deviceid

// 连接设备
_this.createConnect(_this.data.deviceId)

// console.log('_this.data.deviceId: ',_this.data.deviceId)

},
createConnect(deviceId) {

let _this = this
wx.createBLEConnection({
  // 这里的 deviceId 需要已经通过 createBLEConnection 与对应设备建立链接 
  deviceId,
  success(res) {
    // 连接成功
    console.log('连接设备成功：', res)

    // 获取 serviceId
    _this.getServices(deviceId)

    // 监听连接状态
    _this.onConnectionStatus()

    // 停止搜索
    _this.stopDiscoverDevices()
  },
  fail(err) {
    console.warn('err :', err);
  }
})

},
onConnectionStatus() {

wx.onBLEConnectionStateChange(function (res) {
  // 该方法回调中可以用于处理连接意外断开等异常情况
  console.log(`设备 ${res.deviceId} 连接状态变化, 连接状态: ${res.connected}`)
})

},
/**

• @description 获取已连接的蓝牙设备

*/
getConnectDevices(services) {

wx.getConnectedBluetoothDevices({
  services,
  success(res) {
    console.log('已连接的设备:' + JSON.stringify(res))
  },
  fail(err) {
    console.log('err: ', err.errMsg)
  }
})

},
/**

• @description 停止搜索蓝牙设备

*/
stopDiscoverDevices() {

wx.stopBluetoothDevicesDiscovery({
  success(res) {
    console.log('成功链接设备，停止搜索。')
  }
})

},
/**

• @description 获得 services & serviceId

*/
getServices(deviceId) {

let _this = this
wx.getBLEDeviceServices({
  deviceId,
  success(res) {

    console.log('device services:', res.services)

    _this.getConnectDevices([res.services[2].uuid])

    // 获取 serviceId 
    _this.setData({
      serviceId: res.services[2].uuid
    })

    console.log('_this.serviceId :', _this.data.serviceId);

    _this.getCharacteristicsId(_this.data.deviceId, _this.data.serviceId)
  }
})

},
/**

• @description 获得 CharacteristicsId

*/
getCharacteristicsId(deviceId, serviceId) {

let _this = this
wx.getBLEDeviceCharacteristics({
  deviceId,
  serviceId,
  success(res) {
    console.log('Characteristics:', res.characteristics)

    // 设置 characteristicId、characteristicIdNotify
    _this.setData({
      characteristicIdNotify: res.characteristics[0].uuid,
      characteristicId: res.characteristics[0].uuid,
    })

    _this.openNotify(deviceId, serviceId, _this.data.characteristicIdNotify)

    console.log('CharacteristicsId:', res.characteristics[0].uuid)

  }
})

},
/**

• @description 开启 notify

*/
openNotify(deviceId, serviceId, characteristicId) {

let _this = this
wx.notifyBLECharacteristicValueChange({
  state: true,
  deviceId,
  serviceId,
  characteristicId,
  success(res) {
    console.log('notify 开启成功', res.errMsg)

    setTimeout(() => {
      _this.writeDevice(deviceId, serviceId, _this.data.characteristicId)
    }, 2000)
  },
  fail(err) {
    console.log('openNotify err: ', err)
  }
})

},
/**

• @description 向设备写入数据

*/
writeDevice(deviceId, serviceId, characteristicId) {

let _this = this
// 向蓝牙设备发送一个0x00的16进制数据
let senddata = 'test'
let buffer = new ArrayBuffer(senddata.length)
let dataView = new DataView(buffer)
for (var i = 0; i < senddata.length; i++) {
  dataView.setUint8(i, senddata.charAt(i).charCodeAt())
}

// let buffer = new ArrayBuffer(2)
// let dataView = new DataView(buffer)
// dataView.setUint16(0, 3)

wx.writeBLECharacteristicValue({
  deviceId,
  serviceId,
  characteristicId,
  value: buffer,
  success(res) {
    console.log('写入数据成功', res.errMsg)
    _this.readDevice(deviceId, serviceId, _this.data.characteristicId)

  },
  fail(err) {
    console.log('err', err)
  },
  complete() {
    _this.closeConnection(deviceId)
    _this.closeBlue()
  }
})

},
readDevice(deviceId, serviceId, characteristicId) {

let _this = this
// 必须在这里的回调才能获取
wx.onBLECharacteristicValueChange(function (characteristic) {
  console.log('characteristic value comed:', characteristic)
})

wx.readBLECharacteristicValue({
  // 这里的 deviceId 需要已经通过 createBLEConnection 与对应设备建立链接
  deviceId,
  // 这里的 serviceId 需要在 getBLEDeviceServices 接口中获取
  serviceId,
  // 这里的 characteristicId 需要在 getBLEDeviceCharacteristics 接口中获取
  characteristicId,
  success(res) {
    console.log('readBLECharacteristicValue:', res.errCode)
  }
})

},
closeConnection(deviceId) {

wx.closeBLEConnection({
  deviceId,
  success(res) {
    console.log('关闭设备连接：', res)
  }
})

}

})

你期待的结果是什么？实际看到的错误信息又是什么？