微信小程序-蓝牙打印机demo

迷南。 2024-04-17 20:49 81阅读 0赞

对于蓝牙有写入数据的话，需要时低功耗的蓝牙。向低功耗蓝牙设备特征值中写入二进制数据。注意：必须设备的特征值支持 write 才可以成功调用。

> https://developers.weixin.qq.com/miniprogram/dev/api/device/bluetooth-ble/wx.writeBLECharacteristicValue.html

# 先搜索蓝牙设备 #

wxml

<button class="btn" type="primary" bindtap="startSearch" loading='{ {isScanning}}'> 开始搜索 </button>
      <view wx:for="{ {list}}" wx:for-item="item" data-title="{ {item.deviceId}}" data-name="{ {item.name}}" data-advertisData="{ {item.advertisServiceUUIDs}}" wx:key="{ {item.deviceId}}" bindtap="bindViewTap">
          <view class="item">
          <div class="deviceId block">{
       {item.deviceId}}</div>
          <div class="name block">{
       {item.name}}</div>
         </view>    
    </view>

app.BLEInformation.platform = getApp().getPlatform()

data: { 
        list: [],
        services: [],
        serviceId: 0,
        writeCharacter: false,
        readCharacter: false,
        notifyCharacter: false,
        isScanning:false
      },
    
      startSearch: function () { 
        var that = this
        wx.openBluetoothAdapter({ 
          success: function (res) { 
            wx.getBluetoothAdapterState({ 
              success: function (res) { 
                if (res.available) { 
                  if (res.discovering) { 
                    wx.stopBluetoothDevicesDiscovery({ 
                      success: function (res) { 
                        console.log(res)
                      }
                    })
                  }
                  that.checkPemission()
                } else { 
                  wx.showModal({ 
                    title: '提示',
                    content: '本机蓝牙不可用',
                  })
                }
              },
            })
          }, fail: function () { 
            wx.showModal({ 
              title: '提示',
              content: '蓝牙初始化失败，请打开蓝牙',
            })
          }
        })
      },
      checkPemission: function () {   //android 6.0以上需授权地理位置权限
        var that = this
        var platform = app.BLEInformation.platform
        if (platform == "ios") { 
          app.globalData.platform = "ios"
          that.getBluetoothDevices()
        } else if (platform == "android") { 
          app.globalData.platform = "android"
          console.log(app.getSystem().substring(app.getSystem().length - (app.getSystem().length - 8), app.getSystem().length - (app.getSystem().length - 8) + 1))
          if (app.getSystem().substring(app.getSystem().length - (app.getSystem().length - 8), app.getSystem().length - (app.getSystem().length - 8) + 1) > 5) { 
            wx.getSetting({ 
              success: function (res) { 
                console.log(res)
                if (!res.authSetting['scope.userLocation']) { 
                  wx.authorize({ 
                    scope: 'scope.userLocation',
                    complete: function (res) { 
                      that.getBluetoothDevices()
                    }
                  })
                } else { 
                  that.getBluetoothDevices()
                }
              }
            })
          }
        }
      },
      getBluetoothDevices: function () {   //获取蓝牙设备信息
        var that = this
        console.log("start search")
        wx.showLoading({ 
          title: '正在加载',
        })
        that.setData({ 
          isScanning:true
        })
        wx.startBluetoothDevicesDiscovery({ 
          success: function (res) { 
            console.log(res)
            setTimeout(function () { 
              wx.getBluetoothDevices({ 
                success: function (res) { 
                  var devices = []
                  var num = 0
                  for (var i = 0; i < res.devices.length; ++i) { 
                    if (res.devices[i].name != "未知设备") { 
                      devices[num] = res.devices[i]
                      num++
                    }
                  }
                  that.setData({ 
                    list: devices,
                    isScanning:false
                  })
                  wx.hideLoading()
                  wx.stopPullDownRefresh()
                },
              })
            }, 3000)
          },
        })
      },
      bindViewTap: function (e) { 
        var that = this
        wx.stopBluetoothDevicesDiscovery({ 
          success: function (res) {  console.log(res) },
        })
        that.setData({ 
          serviceId: 0,
          writeCharacter: false,
          readCharacter: false,
          notifyCharacter: false
        })
        console.log(e.currentTarget.dataset.title)
        wx.showLoading({ 
          title: '正在连接',
        })
        wx.createBLEConnection({ 
          deviceId: e.currentTarget.dataset.title,
          success: function (res) { 
            console.log(res)
            app.BLEInformation.deviceId = e.currentTarget.dataset.title
            that.getSeviceId()
          }, fail: function (e) { 
            wx.showModal({ 
              title: '提示',
              content: '连接失败',
            })
            console.log(e)
            wx.hideLoading()
          }, complete: function (e) { 
            console.log(e)
          }
        })
      },
      getSeviceId: function () { 
        var that = this
        var platform = app.BLEInformation.platform
        console.log(app.BLEInformation.deviceId)
        wx.getBLEDeviceServices({ 
          deviceId: app.BLEInformation.deviceId,
          success: function (res) { 
            console.log(res)
            that.setData({ 
              services: res.services
            })
            that.getCharacteristics()
          }, fail: function (e) { 
            console.log(e)
          }, complete: function (e) { 
            console.log(e)
          }
        })
      },
      getCharacteristics: function () { 
        var that = this
        var list = that.data.services
        var num = that.data.serviceId
        var write = that.data.writeCharacter
        var read = that.data.readCharacter
        var notify = that.data.notifyCharacter
        wx.getBLEDeviceCharacteristics({ 
          deviceId: app.BLEInformation.deviceId,
          serviceId: list[num].uuid,
          success: function (res) { 
            console.log(res)
            for (var i = 0; i < res.characteristics.length; ++i) { 
              var properties = res.characteristics[i].properties
              var item = res.characteristics[i].uuid
              if (!notify) { 
                if (properties.notify) { 
                  app.BLEInformation.notifyCharaterId = item
                  app.BLEInformation.notifyServiceId = list[num].uuid
                  notify = true
                }
              }
              if (!write) { 
                if (properties.write) { 
                  app.BLEInformation.writeCharaterId = item
                  app.BLEInformation.writeServiceId = list[num].uuid
                  write = true
                }
              }
              if (!read) { 
                if (properties.read) { 
                  app.BLEInformation.readCharaterId = item
                  app.BLEInformation.readServiceId = list[num].uuid
                  read = true
                }
              }
            }
            if (!write || !notify || !read) { 
              num++
              that.setData({ 
                writeCharacter: write,
                readCharacter: read,
                notifyCharacter: notify,
                serviceId: num
              })
             if(num == list.length){ 
               wx.showModal({ 
                 title: '提示',
                 content: '找不到该读写的特征值',
               })
             }else{ 
               that.getCharacteristics()
             }
            } else { 
              that.openControl()
            }
          }, fail: function (e) { 
            console.log(e)
          }, complete: function (e) { 
            console.log("write:"+app.BLEInformation.writeCharaterId)
            console.log("read:"+app.BLEInformation.readCharaterId)
            console.log("notify:"+app.BLEInformation.notifyCharaterId)
          }
        })
      },
      openControl: function () { 
        wx.navigateTo({ 
          url: '../startPrint/startPrint',
        })
      },

# 然后打印 #

下面就是startPrint的代码  
wxml

<view class="body">
      <textarea class="input" bindinput="inputEvent" />  
      <button type="primary" bindtap="sendData">发送(票据可使用)</button>  
       <button type='primary' bindtap='labelTest' loading='{ {isLabelSend}}' disabled='{ {isLabelSend}}'>标签测试</button>  
    </view>

下面是 js 的代码，首先是设置变量

data: { 
        sendContent: "",
        looptime: 0,
        currentTime: 1,
        lastData: 0,
        oneTimeData: 0,
        returnResult: "returnResult",
        canvasWidth: 80,
        canvasHeight: 80,
        buffSize: [],
        buffIndex: 0,
        printNum: [],
        printNumIndex: 0,
        printerNum: 1,
        currentPrint: 1,
        isReceiptSend: false,
        isLabelSend: false
      },

command.setCls() ，需要设置这个，不然内容和上一次重复

onLoad: function(options) { 
        var that = this;
        wx.notifyBLECharacteristicValueChange({ 
          deviceId: app.BLEInformation.deviceId,
          serviceId: app.BLEInformation.notifyServiceId,
          characteristicId: app.BLEInformation.notifyCharaterId,
          state: true,
          success: function(res) { 
            wx.onBLECharacteristicValueChange(function(r) { 
              console.log(`characteristic ${ r.characteristicId} has changed, now is ${ r}`)
            })
          },
          fail: function(e) { 
            console.log('fail', e)
          },
          complete: function(e) { 
            console.log('complete', e)
          }
        })
      },
    
      inputEvent: function(e) {  
        this.setData({ 
          sendContent: e.detail.value
        })
        console.log('sendContent: ', this.sendContent)
      },
    
      sendData: function() {  
        var data = this.data.sendContent + "\n"
        var that = this;
        var command = tsc.jpPrinter.createNew()
        command.setGap(0)
        command.setCls()
        command.setText(60, 90, "TSS24.BF2", 1, 1, data)
        command.setPagePrint()
        that.prepareSend(command.getData())
      },
    
      labelTest: function() {  
        var that = this;
        var canvasWidth = that.data.canvasWidth
        var canvasHeight = that.data.canvasHeight
        var command = tsc.jpPrinter.createNew()
        command.setSize(48, 40)
        command.setGap(0)
        command.setCls() //需要设置这个，不然内容和上一次重复
        command.setQR(1, 120, "L", 5, "A", "airenao.com")
        command.setText(60, 90, "TSS24.BF2", 1, 1, "成都爱热闹")
        command.setText(170, 50, "TSS24.BF2", 1, 1, "小程序测试")
        command.setText(170, 90, "TSS24.BF2", 1, 1, "测试数字12345678")
        command.setText(170, 120, "TSS24.BF2", 1, 1, "测试英文abcdefg")
        command.setText(170, 150, "TSS24.BF2", 1, 1, "测试符号/*-+!@#$")
        wx.canvasGetImageData({ 
          canvasId: 'edit_area_canvas',
          x: 0,
          y: 0,
          width: canvasWidth,
          height: canvasHeight,
          success: function(res) { 
            command.setBitmap(60, 0, 0, res)
          },
          complete: function() { 
            command.setPagePrint()
            that.setData({ 
              isLabelSend: true
            })
            that.prepareSend(command.getData())
          }
        })
    
      },

准备发送内容, printNum 这个是需要打印多少份，buff 是每次打印多少字节数

prepareSend: function(buff) {  
        console.log('buff', buff)
        var that = this
        var time = that.data.oneTimeData
        var looptime = parseInt(buff.length / time);
        var lastData = parseInt(buff.length % time);
        console.log(looptime + "---" + lastData)
        that.setData({ 
          looptime: looptime + 1,
          lastData: lastData,
          currentTime: 1,
        })
        that.Send(buff)
      },
    
      queryStatus: function() {  //查询打印机状态
        var command = esc.jpPrinter.Query();
        command.getRealtimeStatusTransmission(1);
        this.setData({ 
          returnResult: "查询成功"
        })
      },
    
      Send: function(buff) {  //分包发送
        var that = this
        var currentTime = that.data.currentTime
        var loopTime = that.data.looptime
        var lastData = that.data.lastData
        var onTimeData = that.data.oneTimeData
        var printNum = that.data.printerNum //打印多少份
        var currentPrint = that.data.currentPrint
        var buf
        var dataView
        if (currentTime < loopTime) { 
          buf = new ArrayBuffer(onTimeData)
          dataView = new DataView(buf)
          for (var i = 0; i < onTimeData; ++i) { 
            dataView.setUint8(i, buff[(currentTime - 1) * onTimeData + i])
          }
        } else { 
          buf = new ArrayBuffer(lastData)
          dataView = new DataView(buf)
          for (var i = 0; i < lastData; ++i) { 
            dataView.setUint8(i, buff[(currentTime - 1) * onTimeData + i])
          }
        }
        console.log("第" + currentTime + "次发送数据大小为：" + buf.byteLength)
        wx.writeBLECharacteristicValue({ 
          deviceId: app.BLEInformation.deviceId,
          serviceId: app.BLEInformation.writeServiceId,
          characteristicId: app.BLEInformation.writeCharaterId,
          value: buf,
          success: function(res) { 
            console.log('写入成功', res)
          },
          fail: function(e) { 
            console.fail('写入失败', e)
          },
          complete: function() { 
            currentTime++
            if (currentTime <= loopTime) { 
              that.setData({ 
                currentTime: currentTime
              })
              that.Send(buff)
            } else { 
              wx.showToast({ 
                title: '已打印第' + currentPrint + '张',
              })
              if (currentPrint == printNum) { 
                that.setData({ 
                  looptime: 0,
                  lastData: 0,
                  currentTime: 1,
                  isReceiptSend: false,
                  isLabelSend: false,
                  currentPrint: 1
                })
              } else { 
                currentPrint++
                that.setData({ 
                  currentPrint: currentPrint,
                  currentTime: 1,
                })
                console.log("开始打印")
                that.Send(buff)
              }
            }
          }
        })
      },

最后的成品样子  
![在这里插入图片描述][20190831225721484.png]

[20190831225721484.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/17/5f1903f45fc64086b230cdf39f560d4d.png