WM_DEVICECHANGE ???????

[lailton.webmaster]

How capture this event in fivewin.

i wanna know when is pluged a pen drive or other hardware disk

http://msdn.microsoft.com/en-us/library ... 85%29.aspx

someone can help me ?

[lailton.webmaster]

up !

[lailton.webmaster]

go top

[lailton.webmaster]

up.

[anserkk]

Dear Mr.Lailton,

May be useful for you

To detect the Hardware device change, the operating system will send a WM_DEVICECHANGE message to the application when a device change is detected. All we
need to do is handle this message in the window procedure of the application. When the window procedure is called the parameters passed will be as follows.

Parameter & Description
HWND hWnd Handle to the window
UINT uiMessage WM_DEVICECHANGE
WPARAM wParam Device-change event
LPARAM lParam Event-specific data

This means, hWnd will be the handle to our window, uiMessage will be the window
message WM_DEVICECHANGE, wParam will be the device-change event such as
DBT_DEVICEARRIVAL or DBT_DEVICEREMOVECOMPLETE, and finally lParam is a pointer to
the device broadcast header. Below is an example of how you could implement a handler
for WM_DEVICECHANGE

Code: Select all  Expand view

LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT uiMsg, WPARAM wParam, LPARAM lParam)
{
switch (uiMsg)
  {
     case WM_DEVICECHANGE:
     {
        PDEV_BROADCAST_HDR pHdr = (PDEV_BROADCAST_HDR) lParam;
        switch (wParam)
        {
           case DBT_DEVICEARRIVAL:
              MessageBox(hWnd, "A device has been inserted.", "USB Notice", MB_OK);
           break;
           case DBT_DEVICEREMOVECOMPLETE:
              MessageBox(hWnd, "A device has been removed.", "USB Notice", MB_OK);
           break;
        }
     }
     break;
     default:
        return DefWindowProc(hWnd, uiMsg, wParam, lParam);
     break;
  }
  return 0;
}

This code will display a message box when a new device is inserted or removed from the
system, with an appropriate message.

Regards
Anser

[Daniel Garcia-Gil]

Lailton

other way

As a start you could inherit a new Class TMyWindow FROM TWindow and redefine the Method HandleEvent() to process WM_DEVICECHANGE message

like this

Code: Select all  Expand view

function Main()

   local oWnd := TMyWindow():New()

   oWnd:Activate()

return nil

CLASS TMyWindow FROM TWindow

   CLASSDATA lRegistered

   METHOD HandleEvent( nMsg, nWParam, nLParam )

ENDCLASS

METHOD HandleEvent( nMsg, nWParam, nLParam ) CLASS TMyWindow

   if nMsg == WM_DEVICECHANGE
      MsgBeep() // ok, we are receiving WM_DEVICECHANGE  messages
   endif  

return Super:HandleEvent( nMsg, nWParam, nLParam )
 

[lailton.webmaster]

i will try this way

thanks so much for yours reply.

[Baxajaun]

Dear Anser,

could you post a small and whole sample ?

Thanks in advance !

Best regards,

[horacio]

What value WM_DEVICECHANGE has ?. Thank you

Saludos

[cnavarro]

Try

WM_DEVICECHANGE = 537

[Baxajaun]

Dear Anser,

please, could you post a small and whole sample ?

Thanks in advance !

Best regards,

[anserkk]

Dear Anser,

please, could you post a small and whole sample ?

Thanks in advance !

Best regards,

I tried this for experimentation long time back. Unfortunately, as of now, I am unable to locate the sample on my hard drive.

By the way did you try to use the sample posted by Mr.Daniel ? For me, his sample is working fine here on both Harbour and xHarbour.

Instead of return Super:HandleEvent( nMsg, nWParam, nLParam )
change it to
return ::Super:HandleEvent( nMsg, nWParam, nLParam )