Windows Development

using System;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.Devices.Bluetooth.Rfcomm;
using Windows.Devices.Enumeration;

// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238

namespace GI_MobileApp.Pages
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class BTDevicesPage : Page
    {
        private DeviceInformationCollection ServiceDeviceCollection = null;
        public static readonly Guid RfcommChatServiceUuid = Guid.Parse("00001101-0000-1000-8000-00805f9b34fb");

        public BTDevicesPage()
        {
            this.InitializeComponent();
            InitialPara();

        }
 
       
        private void tbtnConnect_Changed(object sender, RoutedEventArgs e)
        {
            on_off();
        }

        /// <summary>
        /// Method for connect and disconnect
        /// </summary>
        private void on_off()
        {
            switch (this.tbtnConnect.IsChecked)
            {
                case null:
                    this.tbtnConnect.Content = "Connect";
                    break;
                case true:
                    this.tbtnConnect.Content = "Disconnect";
                    break;
                case false:
                    this.tbtnConnect.Content = "Connect";
                    scan();
                    break;

            }
        }

      
        private async void scan()
        {
            //Find all paired devices and display them in a list
            ServiceDeviceCollection = await DeviceInformation.FindAllAsync(RfcommDeviceService.GetDeviceSelector(RfcommServiceId.SerialPort));

            if (ServiceDeviceCollection.Count > 0)
            {
                tbRxData.Text = "";
                foreach (var btDeviceice in ServiceDeviceCollection)
                {
                    tbRxData.Text = (btDeviceice.Name);
                }
                tbRxData.Visibility = Visibility;
            }
            else
            {
               
            }
        }

        
        /// <summary>
        /// Method Initialising parameters
        /// </summary>
        private void InitialPara()
        {
            this.tbtnConnect.IsChecked = null;
            this.on_off();
        }
    }
}