// Called by DriveDetector after removable device has been unpluged
private void OnDriveRemoved(object sender, DriveDetectorEventArgs e)
{
// TODO: do clean up here, etc. Letter of the removed drive is in e.Drive;
// Just add report to the listbox
//string s = "Drive removed " + e.Drive;
//listBox1.Items.Add(s);
}
// Called by DriveDetector when removable drive is about to be removed
private void OnQueryRemove(object sender, DriveDetectorEventArgs e)
{
// Should we allow the drive to be unplugged?
//if (checkBoxAskMe.Checked)
//{
// if (MessageBox.Show("Allow remove?", "Query remove",
// MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
// e.Cancel = false; // Allow removal
// else
// e.Cancel = true; // Cancel the removal of the device
//}
}
// Called by DriveDetector when removable device in inserted
private void OnDriveArrived(object sender, DriveDetectorEventArgs e)
{
check_USB();
// Report the event in the listbox.
// e.Drive is the drive letter for the device which just arrived, e.g. "E:\\"
//string s = "Drive arrived " + e.Drive;
//listBox1.Items.Add(s);
// If you want to be notified when drive is being removed (and be able to cancel it),
// set HookQueryRemove to true
//if (checkBoxAskMe.Checked)
// e.HookQueryRemove = true;
}
/// <summary>
/// Message handler which must be called from client form.
/// Processes Windows messages and calls event handlers.
/// </summary>
/// <param name="m"></param>
public void WndProc(ref Message m)
{
int devType;
char c;
if (m.Msg == WM_DEVICECHANGE)
{
// WM_DEVICECHANGE can have several meanings depending on the WParam value...
switch (m.WParam.ToInt32())
{
//
// New device has just arrived
//
case DBT_DEVICEARRIVAL:
devType = Marshal.ReadInt32(m.LParam, 4);
if (devType == DBT_DEVTYP_VOLUME)
{
DEV_BROADCAST_VOLUME vol;
vol = (DEV_BROADCAST_VOLUME)
Marshal.PtrToStructure(m.LParam, typeof(DEV_BROADCAST_VOLUME));
// Get the drive letter
c = DriveMaskToLetter(vol.dbcv_unitmask);
//
// Call the client event handler
//
// We should create copy of the event before testing it and
// calling the delegate - if any
DriveDetectorEventHandler tempDeviceArrived = DeviceArrived;
if (tempDeviceArrived != null)
{
DriveDetectorEventArgs e = new DriveDetectorEventArgs();
e.Drive = c + ":\\";
tempDeviceArrived(this, e);
// Register for query remove if requested
if (e.HookQueryRemove)
{
// If something is already hooked, unhook it now
if (mDeviceNotifyHandle != IntPtr.Zero)
{
RegisterForDeviceChange(false, null);
}
RegisterQuery(c + ":\\");
}
} // if has event handler
}
break;
//
// Device is about to be removed
// Any application can cancel the removal
//
case DBT_DEVICEQUERYREMOVE:
devType = Marshal.ReadInt32(m.LParam, 4);
if (devType == DBT_DEVTYP_HANDLE)
{
// TODO: we could get the handle for which this message is sent
// from vol.dbch_handle and compare it against a list of handles for
// which we have registered the query remove message (?)
//DEV_BROADCAST_HANDLE vol;
//vol = (DEV_BROADCAST_HANDLE)
// Marshal.PtrToStructure(m.LParam, typeof(DEV_BROADCAST_HANDLE));
// if ( vol.dbch_handle ....
//
// Call the event handler in client
//
DriveDetectorEventHandler tempQuery = QueryRemove;
if (tempQuery != null)
{
DriveDetectorEventArgs e = new DriveDetectorEventArgs();
e.Drive = mCurrentDrive; // drive which is hooked
tempQuery(this, e);
// If the client wants to cancel, let Windows know
if (e.Cancel)
{
m.Result = (IntPtr)BROADCAST_QUERY_DENY;
}
else
{
// Change 28.10.2007: Unregister the notification, this will
// close the handle to file or root directory also.
// We have to close it anyway to allow the removal so
// even if some other app cancels the removal we would not know about it...
RegisterForDeviceChange(false, null); // will also close the mFileOnFlash
}
}
}
break;
//
// Device has been removed
//
case DBT_DEVICEREMOVECOMPLETE:
devType = Marshal.ReadInt32(m.LParam, 4);
if (devType == DBT_DEVTYP_VOLUME)
{
devType = Marshal.ReadInt32(m.LParam, 4);
if (devType == DBT_DEVTYP_VOLUME)
{
DEV_BROADCAST_VOLUME vol;
vol = (DEV_BROADCAST_VOLUME)
Marshal.PtrToStructure(m.LParam, typeof(DEV_BROADCAST_VOLUME));
c = DriveMaskToLetter(vol.dbcv_unitmask);
//
// Call the client event handler
//
DriveDetectorEventHandler tempDeviceRemoved = DeviceRemoved;
if (tempDeviceRemoved != null)
{
DriveDetectorEventArgs e = new DriveDetectorEventArgs();
e.Drive = c + ":\\";
tempDeviceRemoved(this, e);
}
// TODO: we could unregister the notify handle here if we knew it is the
// right drive which has been just removed
//RegisterForDeviceChange(false, null);
}
}
break;
}
}
}
