Question

I have written an Application Desktop Toolbar (a.k.a AppBar), it works great except for the fact that if I kill the process, the AppBar code never gets a chance to cleanup by sending an ABM_REMOVE. The problem is that this basically screws the users desktop up. The AppBar is written in .NET using interop code.

Does anyone know of a way to clean this resource up, even in the case of a process kill from TaskManager?

Answer 1

When a process is killed from Task Manager, no events are raised within that application. It’s common to use a seperate helper application that listens for the Win32_ProcessStopTrace event for your process. You can use the WqlEventQuery, which is part of System.Management for this.

Here is some example code for this from a MegaSolutions post.

using System; using System.Collections.Generic;  using System.Text;  using System.Management;    class ProcessObserver : IDisposable  {      ManagementEventWatcher m_processStartEvent = null;      ManagementEventWatcher m_processStopEvent = null;        public ProcessObserver(string processName, EventArrivedEventHandler onStart, EventArrivedEventHandler onStop)      {          WqlEventQuery startQuery = new WqlEventQuery('Win32_ProcessStartTrace', String.Format('ProcessName='{0}'', processName));          m_processStartEvent = new ManagementEventWatcher(startQuery);            WqlEventQuery stopQuery = new WqlEventQuery('Win32_ProcessStopTrace', String.Format('ProcessName='{0}'', processName));          m_processStopEvent = new ManagementEventWatcher(stopQuery);            if (onStart != null)              m_processStartEvent.EventArrived += onStart;            if (onStop != null)              m_processStopEvent.EventArrived += onStop;      }        public void Start()      {          m_processStartEvent.Start();          m_processStopEvent.Start();      }        public void Dispose()      {          m_processStartEvent.Dispose();          m_processStopEvent.Dispose();      }  }