代码如下：

bindViewTap: function () {

    var that = this;

    wx.onBLECharacteristicValueChange(function (res) {

        console.log(‘特征值变化’, res);

        const CharacteristicVal = that.buf2hex(res.value);

        if (res.characteristicId == that.data.wifi_uuid) {

            that.setData({

                device_char: CharacteristicVal

            });

        }

    });

    // 向蓝牙设备发送一个0x00的16进制数据

    let buffer = new ArrayBuffer(1)

    let dataView = new DataView(buffer)

    dataView.setUint8(0, 0)

    wx.writeBLECharacteristicValue({

        deviceId: that.data.deviceId,

        serviceId: that.data.wifi_data.service.uuid,

        characteristicId: that.data.wifi_uuid,

        value: buffer,

        success: function (res) {

            // success

            console.log(“success  指令发送成功”);

            console.log(res);

        },

        fail: function (res) {

            // fail

            console.log(res);

        },

        complete: function (res) {

            // complete

            wx.showModal({

                title: ‘提示’,

                content: res,

                success: function (res) {

                    if (res.confirm) {

                        console.log(‘用户点击确定’)

                    } else if (res.cancel) {

                        console.log(‘用户点击取消’)

                    }

                }

            })

        }

    })

}

点击给设备发送一个16进制的数据，writeBLECharacteristicValue和onBLECharacteristicValueChange都没反应，咋回事？？