| Author |
Message |
Knox
Joined: 07 Apr 2009
Posts: 1
|
 Posted: Tue Apr 07, 2009 4:06 pm Post subject: Iphlpapi.dll -> NotifyAddrChange |
 |
|
I'm not sure how to add a new wiki page, and there isn't one for the NotifyAddrChange function of the Iphlpapi.dll. I am fairly new to .NET C# programming, and it took me a while to figure out how to properly use this call. I figured I would post up what I have here to help any others who might be having trouble with it.
| Code: |
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Runtime.InteropServices;
namespace Iphlpapi
{
public class CNotifyAddrChange
{
public event EventHandler<EventArgs> AddrChangedEvent = null;
protected Thread TheThread { get; set; }
protected enum EEvents
{
AddrChange,
Abort,
Count,
}
protected AutoResetEvent[] m_aoEvents;
[DllImport("Iphlpapi.dll", SetLastError = true)]
public static extern UInt32 NotifyAddrChange(ref IntPtr Handle, ref NativeOverlapped overlapped);
public CNotifyAddrChange()
{
TheThread = null;
m_aoEvents = new AutoResetEvent[(int)EEvents.Count]
{
new AutoResetEvent(false), // AddrChangeEvent
new AutoResetEvent(false), // AbortEvent
};
Start();
}
~CcpNotifyAddrChange()
{
Abort();
}
protected AutoResetEvent AddrChangeEvent
{
get
{
return m_aoEvents[(int)EEvents.AddrChange];
}
}
protected AutoResetEvent AbortEvent
{
get
{
return m_aoEvents[(int)EEvents.Abort];
}
}
public void Start()
{
Abort();
TheThread = new Thread(new ThreadStart(ThreadProc));
TheThread.Name = "NotifyAddrChange";
TheThread.Start();
}
public void Abort()
{
if( (TheThread != null) && TheThread.IsAlive )
{
AbortEvent.Set();
TheThread.Join();
}
}
public void ThreadProc()
{
try
{
NativeOverlapped oOverlapped = new NativeOverlapped();
IntPtr pnHandle = IntPtr.Zero;
oOverlapped.EventHandle = AddrChangeEvent.SafeWaitHandle.DangerousGetHandle();
while(true)
{
if(NotifyAddrChange(ref pnHandle, ref oOverlapped) == 997) // 997 == ERROR_IO_PENDING
{
if (WaitHandle.WaitAny(m_aoEvents) == (Int32)EEvents.AddrChange)
{
EventHandler<EventArgs> oHandler = AddrChangedEvent;
if(oHandler != null)
{
oHandler(this, null);
}
}
else
{
// The abort event was triggered
break;
}
}
else
{
// Handle the error
break;
}
}
}
catch (System.Exception oException)
{
// Handle the error
}
}
}
}
|
How to use:
1) Create the event handler function that you want called when an address changes
| Code: |
public void OnAddrChangedEvent(object sender, EventArgs e)
{
try
{
// Do whatever it is you need to do when an address changes
}
catch (System.Exception oException)
{
// Handle the error
}
}
|
2) Create the object within the scope you want it to run and assign your event handler.
| Code: |
CNotifyAddrChange oAddrChange = new CNotifyAddrChange();
oAddrChange.AddrChangedEvent += OnAddrChangedEvent;
|
3) When you are ready to shut it down, simply call Abort
| Code: |
oAddrChange.Abort();
|
|
|
| Back to top |
|
 |
Brian Donahue
Joined: 23 Aug 2004
Posts: 6369
Location: Red Gate Software
|
| Posted: Wed Apr 08, 2009 9:56 am Post subject: |
|
|
Hi,
It's easy to create a page for a new function in the PInvoke wiki. Just click the text box at the top of each page that says navigate or create a new function and enter Iphlpapi.NotifyAddrChange.
The only time you would need administrator help would be when you need to add a new module to the wiki. I pick these requests up when moderating the forum and add new modules when requested.
Hope this helps!
_________________
Brian Donahue
Technical Support
Red Gate Software Ltd.
44 (0)870 160 0037 ext 8521
US and CAN 1-866-RED GATE ext 8521 |
|
| Back to top |
|
|
|
|
All times are GMT + 1 Hour
|
| Page 1 of 1 |
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
