var buffer = new ArrayBuffer(16)

var dataView = new DataView(buffer)

var str = ‘0xd3,0x80,0x60,0x79,0x76,0xc9,0xdd,0x46,0xe5,0x18,0xf4,0x31,0xf6,0x4e,0xb6,0x44’;

var arr = str.split(’,’)

var val;

for (var i = 0; i < arr.length; i++) {

val = parseInt(arr[i], 16)

dataView.setInt8(i, val);

}

wx.writeBLECharacteristicValue({

deviceId: that.data.deviceId,

serviceId: that.data.services,

characteristicId: that.data.characteristicsFEC7,

value: buffer,

success: function (res) {

console.log(res,‘writeBLECharacteristicValue success’);

//启用低功耗蓝牙设备特征值变化时的 notify 功能

wx.notifyBLECharacteristicValueChanged({

deviceId: that.data.deviceId,

serviceId: that.data.services,

characteristicId: that.data.characteristicsFEC8,

state: true,

success: function (res) {

console.log(“notifyBLECharacteristicValueChanged”, res);

},

fail: function (res) {

console.log(“uuid ble cvc fail>>>>>>>888888888”, res);

},

});

// 必须在这里的回调才能获\

setTimeout(function(){

wx.onBLECharacteristicValueChange(function (characteristic) {

console.log(‘onBLECharacteristicValueChang:’, characteristic);

const base64 = Array.prototype.map.call(new Uint8Array(characteristic.value), x => (‘00’ + x.toString(16)).slice(-2)).join(’’);

console.log(base64)

})

},3000)

setTimeout(function(){

//读取低功耗蓝牙设备的特征值的二进制数据值

wx.readBLECharacteristicValue({

deviceId: that.data.deviceId,

serviceId: that.data.services,

characteristicId: that.data.characteristicsFEC9,

success: function (res) {

console.log(‘readBLECharacteristicValue++++++++++++++++++++++:’, res)

},

fail: function (res) {

console.log(‘readBLECharacteristicValue fail:’, res)

},

})

},3000)

},

fail: function (res) {

console.log(res,‘buff fail’)

}

})

readBLECharacteristicValue成功后不应该返回两个参数吗

我怎么都没有characteristic这个参数

只有errMsg与errcode   ++++加号后面的是我的返回值