Example that shows how to leverage the XboxBigButton controller library code to control either VLC or Netflix using the Xbox 360 Big Button Controllers

VideoPlayerController.cs

public partial class Form1 : Form
{
    public enum Players
    {
        None,
        VLC,
        Netflix
    }

    /// <summary>
    /// Brings the thread that created the specified window into the foreground and activates the window. 
    /// Keyboard input is directed to the window.
    /// </summary>
    /// <param name="hWnd">A handle to the window that should be activated and brought to the foreground.</param>
    /// <returns>If the window was brought to the foreground, the return value is true.
    /// If the window was not brought to the foreground, the return value is false.</returns>
    [DllImport("user32.DLL")]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool SetForegroundWindow(IntPtr hWnd);

    /// <summary>
    /// Determines whether the specified window handle identifies an existing window.
    /// </summary>
    /// <param name="hWnd"></param>
    /// <returns></returns>
    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool IsWindow(IntPtr hWnd);

    /// <summary>
    /// The big button controller
    /// </summary>
    private readonly XboxBigButtonDevice _device;

    /// <summary>
    /// Time when the last keypress was received from the controller, use this to discard excessive repeating keys
    /// </summary>
    private DateTime _lastKeyTime = DateTime.MinValue;

    /// <summary>
    /// Handle to the VLC window
    /// </summary>
    private IntPtr _windowHandle = IntPtr.Zero;

    /// <summary>
    /// Which player is selected in the UI
    /// </summary>
    private Players _player;
    
    /// <summary>
    /// Gets or sets which video player the remote controls control
    /// </summary>
    public Players Player
    {
        get { return _player; }
        set
        {
            // If setting to the same thing, just exit
            if (_player == value)
                return;

            // Switch player
            _player = value;

            // Force a refetching of the window
            _windowHandle = IntPtr.Zero;
        }
    }

    public Form1()
    {
        InitializeComponent();

        _device = new XboxBigButtonDevice();
        _device.ButtonStateChanged += _device_ButtonStateChanged;

        _device.Connect();
    }

    private void _device_ButtonStateChanged(object sender, XboxBigButtonDeviceEventArgs e)
    {
        if (this.InvokeRequired)
            this.BeginInvoke(new Action(() => this.SendKeysToWindow(e.Controller, e.ButtonState)));
        else
            this.SendKeysToWindow(e.Controller, e.ButtonState);
    }

    private void SendKeysToWindow(Controller controller, Buttons buttons)
    {
        // If the last key event was within tolerance then don't listen
        if ((DateTime.Now - _lastKeyTime).TotalMilliseconds < 500)
            return;

        // The back button controls which player we're dealing with
        if (buttons.IsPressed(Buttons.Back))
        {
            if (cbUsingVLCMediaPlayer.Checked)
                cbUsingNetflix.Checked = true;
            else
                cbUsingVLCMediaPlayer.Checked = true;

            // Save the time if we successfully sent keys
            _lastKeyTime = DateTime.Now;

            return;
        }

        string keysToSend;

        // Which player are we dealing with
        if (this.Player == Players.VLC)
            keysToSend = ControlVLCPlayer(controller, buttons);
        else if (this.Player == Players.Netflix)
            keysToSend = ControlNetflix(controller, buttons);
        else
            return;

        // If no keys then don't do anything
        if (string.IsNullOrEmpty(keysToSend))
            return;

        // Set the window to foreground, only send keys if the window was successfully brought forward
        if (SetForegroundWindow(_windowHandle))
        {
            // Send the keys
            SendKeys.SendWait(keysToSend);

            // Save the time if we successfully sent keys
            _lastKeyTime = DateTime.Now;
        }
    }

    private string ControlNetflix(Controller controller, Buttons buttons)
    {
        // If we don't have the VLC window yet or the window has been restarted (has a new handle)
        // then let's try to find the handle
        if (!IsWindowHandleValid(_windowHandle))
        {
            _windowHandle = FindWindowHandle("Netflix - ");

            // No valid Netflix browser windowhandle could be found, exit
            if (!IsWindowHandleValid(_windowHandle))
                return null;
        }

        // Translate key mappings
        return GetNetflixKeysToSend(controller, buttons);
    }

    private string ControlVLCPlayer(Controller controller, Buttons buttons)
    {
        // If we don't have the VLC window yet or the window has been restarted (has a new handle)
        // then let's try to find the handle
        if (!IsWindowHandleValid(_windowHandle))
        {
            _windowHandle = FindWindowHandle("VLC media player");

            // No valid VLC windowhandle could be found, exit
            if (!IsWindowHandleValid(_windowHandle))
                return null;
        }

        // Translate key mappings
        return GetVLCKeysToSend(controller, buttons);
    }

    private string GetNetflixKeysToSend(Controller controller, Buttons buttons)
    {
        string keys = "";

        // For more info on SendKeys see:
        // https://msdn.microsoft.com/en-us/library/system.windows.forms.sendkeys(v=vs.110).aspx

        // Play/pause
        if (buttons.IsPressed(Buttons.BigButton))
            keys += " ";

        // Skip medium forward
        if (buttons.IsPressed(Buttons.Left))
            keys += "{LEFT}";

        // Skip medium backward
        if (buttons.IsPressed(Buttons.Right))
            keys += "{RIGHT}";

        // Fullscreen
        if (buttons.IsPressed(Buttons.Home))
            keys += "f";

        // Mute
        if (buttons.IsPressed(Buttons.Y))
            keys += "m";

        return keys;
    }

    /// <summary>
    /// Translates the big button controller keys into VLC keys
    /// </summary>
    private string GetVLCKeysToSend(Controller controller, Buttons buttons)
    {
        string keys = "";

        // For more info on SendKeys see:
        // https://msdn.microsoft.com/en-us/library/system.windows.forms.sendkeys(v=vs.110).aspx
        
        // Play/pause
        if (buttons.IsPressed(Buttons.BigButton))
            keys += " ";

        // Skip medium forward
        if (buttons.IsPressed(Buttons.Left))
            keys += "^({LEFT})";

        // Skip medium backward
        if (buttons.IsPressed(Buttons.Right))
            keys += "^({RIGHT})";

        // Volume Up
        if (buttons.IsPressed(Buttons.Up))
            keys += "^({UP})";

        // Volume Down
        if (buttons.IsPressed(Buttons.Down))
            keys += "^({DOWN})";

        // Subtitles 
        if (buttons.IsPressed(Buttons.A))
            keys += "v";

        // Audio
        if (buttons.IsPressed(Buttons.B))
            keys += "b";

        // Fullscreen
        if (buttons.IsPressed(Buttons.Home))
            keys += "f";

        // Mute
        if (buttons.IsPressed(Buttons.Y))
            keys += "m";

        return keys;
    }

    private IntPtr FindWindowHandle(string windowTitle)
    {
        foreach (Process proc in Process.GetProcesses())
        {
            if (proc.MainWindowTitle.Contains(windowTitle))
            {
                return proc.MainWindowHandle;
            }
        }
        return IntPtr.Zero;
    }

    private bool IsWindowHandleValid(IntPtr windowHandle)
    {
        return windowHandle != IntPtr.Zero && IsWindow(windowHandle);
    }


    private void cbUsingVLCMediaPlayer_CheckedChanged(object sender, EventArgs e)
    {
        if (!cbUsingVLCMediaPlayer.Checked)
            return;

        cbUsingNetflix.Checked = false;
        this.Player = Players.VLC;
    }

    private void cbUsingNetflix_CheckedChanged(object sender, EventArgs e)
    {
        if (!cbUsingNetflix.Checked) 
            return;

        cbUsingVLCMediaPlayer.Checked = false;
        this.Player = Players.Netflix;
    }

    private void Form1_FormClosed(object sender, FormClosedEventArgs e)
    {
        if(_device != null )
        {
            _device.Disconnect();
            _device.Dispose();
        }
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        // Initially select the VLC button
        cbUsingVLCMediaPlayer.Checked = true;
    }
}

public static class ButtonsExtensions
{
    /// <summary>
    /// Checks if the supplied check buttons are currently pressed (note that other buttons can be pressed)
    /// </summary>
    /// <param name="currentState"></param>
    /// <param name="check"></param>
    /// <returns></returns>
    public static bool IsPressed(this Buttons currentState, Buttons check)
    {
        return (currentState & check) == check;
    }
}