32Feet.NET. How to pair PC with a device?

I write an application for Windows Form. I have a problem with pairing a device with PC. Now the program works next way: switch on the divece, start the program, add divece to Bluetooth device, push connect button. I use the next functions:

    public BluetoothClient client = new BluetoothClient();
    public string selectedItem { get; set; }
    public BluetoothDeviceInfo[] AllDevices;

    public void GetDevices()
    {
        AllDevices = client.DiscoverDevicesInRange();
        foreach (BluetoothDeviceInfo Device in AllDevices)
        {
            if(Device.DeviceName.Contains("Kortes"))
                onSetDevices(Device.DeviceName); // event to get device name and add it to ComoBox element on form
        }
        onSetProgress(); // event, that all devices were found, set progress bar and etc.
    }
    public void GoConnect()
    {
        foreach (BluetoothDeviceInfo Device in AllDevices)
        {
            if (Device.DeviceName.Equals(selectedItem)) // item from ComboBox
            {
                if (!client.Connected)
                    client = new BluetoothClient();
                client.BeginConnect(Device.DeviceAddress, Device.InstalledServices[0], this.BluetoothClientConnectCallback, client);
                break;
            }
            else 
            {
                MessageBox.Show("Choose the device");
            }
        }
    }
    private void BluetoothClientConnectCallback(IAsyncResult ar)
    {
        //Have no problem with this
    }

These functions work very well. I can find and connect with needed device. But the problem is that firstly I need to add my device to Bluetooth device in OS and enter PIN code. How can I improve my code to solve this problem?

I don't want to add device. I want to work with it directly. Which methods can I use to enter PIN code programmatically? The program must work the next way: switch on the device, start the program, and push connect button.

You are trying to connect without pairing.Your code is not working because you have to pair before connecting.

replace

client = new BluetoothClient();

client.BeginConnect(Device.DeviceAddress, Device.InstalledServices[0], this.BluetoothClientConnectCallback, client);

by

BluetoothSecurity.PairRequest(Device.DeviceAddress,"123456");

Check out http://mrbikash.com/bluetooth-discovery-pairing-32feet-net/#pairing for a more detailed explanation.