c# - Hide mouse cursor after an idle time

Question

I want to hide my mouse cursor after an idle time and it will be showed up when I move the mouse. I tried to use a timer but it didn't work well. Can anybody help me? Please!

Answer 1

If you are using WinForms and will only deploy on Windows machines then it's quite easy to use user32 GetLastInputInfo to handle both mouse and keyboard idling.

public static class User32Interop
{
  public static TimeSpan GetLastInput()
  {
    var plii = new LASTINPUTINFO();
    plii.cbSize = (uint)Marshal.SizeOf(plii);

    if (GetLastInputInfo(ref plii))
      return TimeSpan.FromMilliseconds(Environment.TickCount - plii.dwTime);
    else
      throw new Win32Exception(Marshal.GetLastWin32Error());
  }

  [DllImport("user32.dll", SetLastError = true)]
  static extern bool GetLastInputInfo(ref LASTINPUTINFO plii);

  struct LASTINPUTINFO
  {
    public uint cbSize;
    public uint dwTime;
  }
}

And then in your Form

public partial class MyForm : Form
{
  Timer activityTimer = new Timer();
  TimeSpan activityThreshold = TimeSpan.FromMinutes(2);
  bool cursorHidden = false;

  public Form1()
  {
    InitializeComponent();

    activityTimer.Tick += activityWorker_Tick;
    activityTimer.Interval = 100;
    activityTimer.Enabled = true;
  }

  void activityWorker_Tick(object sender, EventArgs e)
  {
    bool shouldHide = User32Interop.GetLastInput() > activityThreshold;
    if (cursorHidden != shouldHide)
    {
      if (shouldHide)
        Cursor.Hide();
      else
        Cursor.Show();

      cursorHidden = shouldHide;
    }
  }
}