C# Signature:

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

VB Signature:

<DllImport("user32.dll")> _
Shared Function GetLastInputInfo(ByRef plii As LASTINPUTINFO) As Boolean
End Function

C++ Signature:

[DllImport("user32.dll")]
static bool GetLastInputInfo(LASTINPUTINFO* plii);

User-Defined Types:

LASTINPUTINFO

Notes:

Very useful to detect user-idle state of an application.

Minimum operating systems: Windows 2000

Tips & Tricks:

Compare to Environment.TickCount to get the time since the last user input.

Sample Code:

These samples do not take into account the rollover of the tick counter which will occur after ~50 days of uptime.

This function retrieves the time in seconds since last user input

    static uint GetLastInputTime()
    {
        uint idleTime = 0;
        LASTINPUTINFO lastInputInfo = new LASTINPUTINFO();
        lastInputInfo.cbSize = (uint)Marshal.SizeOf( lastInputInfo );
        lastInputInfo.dwTime = 0;

        uint envTicks = (uint)Environment.TickCount;

        if ( GetLastInputInfo( ref lastInputInfo ) )
        {
        uint lastInputTick = lastInputInfo.dwTime;

        idleTime = envTicks - lastInputTick;
        }

        return (( idleTime > 0 ) ? ( idleTime / 1000 ) : 0);
    }

Sample Code vb.net:

This function retrieves the time in seconds since last user input

Dim idletime As Integer
Dim lastInputInf As New LASTINPUTINFO()

   Public Function GetLastInputTime() As Integer

    idletime = 0
    lastInputInf.cbSize = Marshal.SizeOf(lastInputInf)
    lastInputInf.dwTime = 0

    If GetLastInputInfo(lastInputInf) Then
        idletime = Environment.TickCount - lastInputInf.dwTime
    End If

    If idletime > 0 Then
        Return idletime / 1000
    Else : Return 0
    End If

   End Function

Sample Code C++ .net:

This function retrieves the time in seconds since last user input

public: static double getSystemIdleTime()
{                    
    int systemUptime = Environment::TickCount;
    int idleTicks = 0;
    LASTINPUTINFO lastInputInfo;
    lastInputInfo.cbSize = (UInt32)Marshal::SizeOf(lastInputInfo);
    lastInputInfo.dwTime = 0;
    if (GetLastInputInfo(&lastInputInfo))
    {        
        int lastInputTicks = (int)lastInputInfo.dwTime;
        idleTicks = systemUptime - lastInputTicks;
    }
    return (( idleTicks > 0 ) ? ( idleTicks / 1000 ) : idleTicks );
}

Alternative Managed API:

Do you know one? Please contribute it!

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).