// 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; } } }