# 已连接对端设备查询

Wear Engine提供查询用户在穿戴侧已连接的对端设备列表的接口。

建议开发者在使用Wear Engine其他API接口前先实现该接口功能，从已连接的对端设备列表中选定设备。

1. 调用[getDeviceClient](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/wearengine_api#wearenginegetdeviceclient)方法，获取[DeviceClient](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/wearengine_api#deviceclient)对象。

2. 调用[getConnectedDevices](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/wearengine_api#getconnecteddevices)方法，查询用户已连接的对端设备列表。

3. 从已连接设备列表中选定需要通信的对端设备。

4. 查询对端设备的操作系统类型。

   ```typescript
   // 在使用Wear Engine服务前，请导入wearEngine与相关模块
   import { wearEngine } from '@kit.WearEngine';
   import { BusinessError } from '@kit.BasicServicesKit';

   // 步骤1：获取DeviceClient对象
   // this.getUIContext().getHostContext() 表示应用上下文Context对象
   let deviceClient: wearEngine.DeviceClient = wearEngine.getDeviceClient(this.getUIContext().getHostContext());
   // 声明目标设备
   let targetDevice: wearEngine.Device;

   // 步骤2：调用getConnectedDevices方法，查询用户是否有已连接的对端设备
   deviceClient.getConnectedDevices().then(devices => {
     console.info(`Succeeded in getting deviceList, deviceList number is ${devices.length}`);
     // 步骤3：从已连接设备列表中选定需要通信的设备
     if (devices.length > 0) {
       targetDevice = devices[0];
       console.info(`Succeeded in getting target device.`);
       // 步骤4：查询对端设备的操作系统类型
       let osCategory: wearEngine.OsCategory | undefined = targetDevice.osCategory;
       console.info(`The osCategory of target device is ${osCategory}`);
     } else {
       console.error(`Failed to get target device. deviceList is empty.`);
     }
   }).catch((error: BusinessError) => {
     // 处理调用失败时捕获到的异常
     console.error(`Failed to get deviceList. Code is ${error.code}, message is ${error.message}`);
   });
   ```