如何在Plugin.Ble中等待列表填充？

using Plugin.Ble;
using Plugin.Ble.Abstractions.Contracts;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;

public class BluetoothManager
{
    private readonly IBluetoothLE bluetoothLE;
    private IList<IDevice> deviceList;

    public BluetoothManager()
    {
        bluetoothLE = CrossBluetoothLE.Current;
        deviceList = new List<IDevice>();
    }

    public async Task<IList<IDevice>> GetDeviceListAsync()
    {
        // 开始扫描蓝牙设备
        bluetoothLE.Adapter.ScanMode = ScanMode.LowLatency;
        bluetoothLE.Adapter.ScanTimeout = TimeSpan.FromSeconds(10);
        bluetoothLE.Adapter.DeviceDiscovered += (s, e) =>
        {
            // 将扫描到的设备添加到列表中
            deviceList.Add(e.Device);
        };

        // 等待扫描完成
        await bluetoothLE.Adapter.StartScanningForDevicesAsync();

        // 返回设备列表
        return deviceList;
    }
}