鸿蒙蓝牙连接

• ble.startBLEScan

startBLEScan(filters: Array, options?: ScanOptions): void
发起BLE扫描流程。
需要权限：ohos.permission.ACCESS_BLUETOOTH

import { BusinessError } from '@ohos.base';
function onReceiveEvent(data: Array<ble.ScanResult>) {
    console.info('BLE scan device find result = '+ JSON.stringify(data));
}
try {
    ble.on("BLEDeviceFind", onReceiveEvent);
    let scanFilter: ble.ScanFilter = {
            deviceId:"XX:XX:XX:XX:XX:XX",
            name:"test",
            serviceUuid:"00001888-0000-1000-8000-00805f9b34fb"
        };
    let scanOptions: ble.ScanOptions = {
    interval: 500,
    dutyMode: ble.ScanDuty.SCAN_MODE_LOW_POWER,
    matchMode: ble.MatchMode.MATCH_MODE_AGGRESSIVE,
    }
    ble.startBLEScan([scanFilter],scanOptions);
} catch (err) {
    console.error('errCode: ' + (err as BusinessError).code + ', errMessage: ' + (err as BusinessError).message);
}

• ble.stopBLEScan

stopBLEScan(): void
停止BLE扫描流程。
需要权限：ohos.permission.ACCESS_BLUETOOTH

import { BusinessError } from '@ohos.base';
try {
    ble.stopBLEScan();
} catch (err) {
    console.error('errCode: ' + (err as BusinessError).code + ', errMessage: ' + (err as BusinessError).message);
}

• connect
  connect(): void
  client端发起连接远端蓝牙低功耗设备。
  需要权限：ohos.permission.ACCESS_BLUETOOTH

import { BusinessError } from '@ohos.base';
try {
    let device: ble.GattClientDevice = ble.createGattClientDevice('XX:XX:XX:XX:XX:XX');
    device.connect();
} catch (err) {
    console.error('errCode: ' + (err as BusinessError).code + ', errMessage: ' + (err as BusinessError).message);
}

• disconnect
  disconnect(): void
  client端断开与远端蓝牙低功耗设备的连接。
  需要权限：ohos.permission.ACCESS_BLUETOOTH

import { BusinessError } from '@ohos.base';
try {
    let device: ble.GattClientDevice = ble.createGattClientDevice('XX:XX:XX:XX:XX:XX');
    device.disconnect();
} catch (err) {
    console.error('errCode: ' + (err as BusinessError).code + ', errMessage: ' + (err as BusinessError).message);
}

• 下面是测试例子：

import { BusinessError } from '@ohos.base';
import ble from '@ohos.bluetooth.ble';
import { TAG } from '@ohos/hypium/src/main/Constant';

@Entry
@Component
struct BluetoothText {
  @State message: string = '蓝牙测试界面';
  @State scanResults: Array<string> = [];  // 存储扫描结果
  private scannedDeviceIds: Set<string> = new Set();  // 存储已经扫描到的设备ID
  private targetDeviceId: string = "7C:87:CE:1D:DF:F2";  // 目标设备的Device ID
  private gattClientDevice: ble.GattClientDevice | null = null;
  mBorder: BorderOptions = { radius: 10, color: '#385E0F', width: 1 };
  fontSize = 16
  mColor: string = '#2E8B57'

  build() {
    Row() {
      Column() {
        // 显示当前状态信息
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
        Row() {
          Button("连接")
            .fontSize(this.fontSize)
            .height('60%')
            .width('40%')
            .border(this.mBorder)
            .backgroundColor(this.mColor)
            .onClick(() => {
              this.startBLEScan();
            });
          Button("停止")
            .fontSize(this.fontSize)
            .height('60%')
            .width('40%')
            .border(this.mBorder)
            .backgroundColor(this.mColor)
            .onClick(() => {
              this.stopBLEScan();
            });
        }.width('30%').height('10%').padding({ left: 10, right: 10 })

        // 滚动容器，用于显示扫描结果列表
        Scroll() {
          Column() {  // 使用 Column 作为 Scroll 的唯一子组件
            ForEach(this.scanResults, (result: string) => {
              Text(result)
                .fontSize(20)
                .fontColor(Color.Black)
                .padding(10)
            })
          }
        }
        .height('80%')  // 设置滚动区域高度
        .width('100%')
      }
      .width('100%')
    }
    .height('100%')
  }

  startBLEScan() {// 使用箭头函数定义
    try {
      ble.on("BLEDeviceFind", this.onReceiveEvent);  // 直接传递引用
      let scanFilter: ble.ScanFilter = {
        deviceId: this.targetDeviceId,
      };

      let scanOptions: ble.ScanOptions = {
        interval: 500,
        dutyMode: ble.ScanDuty.SCAN_MODE_LOW_POWER,
        matchMode: ble.MatchMode.MATCH_MODE_AGGRESSIVE,
      };

      ble.startBLEScan([scanFilter], scanOptions);

      this.message = 'Scanning...';
    } catch (err) {
      console.error('errCode: ' + err.code + ', errMessage: ' + err.message);
      this.message = 'Scan failed: ' + err.message;
    }
  }

  onReceiveEvent = (data: Array<ble.ScanResult>) => {
    console.info('BLE scan device find result = ' + JSON.stringify(data));

    let newResults = data.map((device) => {
      if (!this.scannedDeviceIds.has(device.deviceId)) {
        this.scannedDeviceIds.add(device.deviceId);  // 添加设备ID到集合中

        if (device.deviceId === this.targetDeviceId) {
          // 创建并连接到 GATT 客户端设备
          try {
            this.gattClientDevice = ble.createGattClientDevice(device.deviceId);
            this.gattClientDevice.connect();
            console.debug(TAG,"连接成功")
          } catch (err) {
            console.error('创建GATT客户端设备失败，errCode: ' + (err as BusinessError).code + ', errMessage: ' + (err as BusinessError).message);
            this.message = '创建GATT客户端设备失败';
          }
        }
        console.debug(TAG,`Device Name: ${device.deviceName || 'Unknown'}, Device ID: ${device.deviceId}`);
        return `Device Name: ${device.deviceName || 'Unknown'}, Device ID: ${device.deviceId}`;
      }
      return null;
    }).filter(result => result !== null);  // 过滤掉 null 值

    this.scanResults = [...this.scanResults, ...newResults as string[]];  // 合并新旧结果
    this.message = 'Scan result received!';
  }

  //停止蓝牙扫描
  stopBLEScan(){
    try {
      ble.stopBLEScan();
      this.gattClientDevice?.disconnect();
    } catch (err) {
      console.error('errCode: ' + (err as BusinessError).code + ', errMessage: ' + (err as BusinessError).message);
    }
  }
}