diff --git a/include/wx/listbox.h b/include/wx/listbox.h
index cc15c6764e..cd4c0fa6f8 100644
--- a/include/wx/listbox.h
+++ b/include/wx/listbox.h
@@ -96,10 +96,13 @@ public:
     int HitTest(int x, int y) const { return DoListHitTest(wxPoint(x, y)); }
 
 
-    // For generating events in multiple and extended mode
+    // For generating events in multiple and extended mode: compare the current
+    // selections with the previously recorded ones (in m_oldSelections) and
+    // send the appropriate event if they differ, otherwise just return false.
+    bool CalcAndSendEvent();
+
     wxArrayInt m_oldSelections;
     void UpdateOldSelections();
-    void CalcAndSendEvent();
 
 protected:
     virtual void DoSetFirstItem(int n) = 0;
@@ -110,6 +113,11 @@ protected:
     virtual int DoListHitTest(const wxPoint& WXUNUSED(point)) const
         { return wxNOT_FOUND; }
 
+    // Send a listbox (de)selection or double click event.
+    //
+    // Returns true if the event was processed.
+    bool SendEvent(wxEventType evtType, int item, bool selected);
+
 private:
     wxDECLARE_NO_COPY_CLASS(wxListBoxBase);
 };
diff --git a/src/common/lboxcmn.cpp b/src/common/lboxcmn.cpp
index a9beae01cc..f7d4fb91a8 100644
--- a/src/common/lboxcmn.cpp
+++ b/src/common/lboxcmn.cpp
@@ -90,29 +90,33 @@ void wxListBoxBase::UpdateOldSelections()
         GetSelections( m_oldSelections );
 }
 
-static void LBSendEvent( wxCommandEvent &event, wxListBoxBase *listbox, int item )
+bool wxListBoxBase::SendEvent(wxEventType evtType, int item, bool selected)
 {
-    event.SetInt( item );
-    event.SetString( listbox->GetString( item ) );
-    if ( listbox->HasClientObjectData() )
-        event.SetClientObject( listbox->GetClientObject(item) );
-    else if ( listbox->HasClientUntypedData() )
-        event.SetClientData( listbox->GetClientData(item) );
-    listbox->HandleWindowEvent( event );
+    wxCommandEvent event(evtType, GetId());
+    event.SetEventObject(this);
+
+    event.SetInt(item);
+    event.SetString(GetString(item));
+    event.SetExtraLong(selected);
+
+    if ( HasClientObjectData() )
+        event.SetClientObject(GetClientObject(item));
+    else if ( HasClientUntypedData() )
+        event.SetClientData(GetClientData(item));
+
+    return HandleWindowEvent(event);
 }
 
-void wxListBoxBase::CalcAndSendEvent()
+bool wxListBoxBase::CalcAndSendEvent()
 {
-    wxCommandEvent event(wxEVT_COMMAND_LISTBOX_SELECTED, GetId());
-    event.SetEventObject( this );
-
     wxArrayInt selections;
     GetSelections(selections);
+    bool selected = true;
 
     if ( selections.empty() && m_oldSelections.empty() )
     {
         // nothing changed, just leave
-        return;
+        return false;
     }
 
     const size_t countSel = selections.size(),
@@ -131,14 +135,13 @@ void wxListBoxBase::CalcAndSendEvent()
 
         // nothing changed, just leave
         if ( !changed )
-           return;
+           return false;
     }
 
     int item = wxNOT_FOUND;
     if ( selections.empty() )
     {
-        // indicate that this is a deselection
-        event.SetExtraLong(0);
+        selected = false;
         item = m_oldSelections[0];
     }
     else // we [still] have some selections
@@ -155,14 +158,9 @@ void wxListBoxBase::CalcAndSendEvent()
             }
         }
 
-        if ( any_new_selected )
+        if ( !any_new_selected )
         {
-            // indicate that this is a selection
-            event.SetExtraLong(1);
-        }
-        else // no new items selected
-        {
-            // Now test if any new item is deselected
+            // No new items selected, now test if any new item is deselected
             bool any_new_deselected = false;
             for ( size_t idx = 0; idx < countSelOld; idx++ )
             {
@@ -177,7 +175,7 @@ void wxListBoxBase::CalcAndSendEvent()
             if ( any_new_deselected )
             {
                 // indicate that this is a selection
-                event.SetExtraLong(0);
+                selected = false;
             }
             else
             {
@@ -191,7 +189,7 @@ void wxListBoxBase::CalcAndSendEvent()
 
     m_oldSelections = selections;
 
-    LBSendEvent(event, this, item);
+    return SendEvent(wxEVT_COMMAND_LISTBOX_SELECTED, item, selected);
 }
 
 // ----------------------------------------------------------------------------
diff --git a/src/msw/listbox.cpp b/src/msw/listbox.cpp
index d36f5ab109..8d2d266c72 100644
--- a/src/msw/listbox.cpp
+++ b/src/msw/listbox.cpp
@@ -647,16 +647,13 @@ wxSize wxListBox::DoGetBestClientSize() const
 
 bool wxListBox::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
 {
-    if ((param == LBN_SELCHANGE) && HasMultipleSelection())
-    {
-        CalcAndSendEvent();
-        return true;
-    }
-
     wxEventType evtType;
     int n;
     if ( param == LBN_SELCHANGE )
     {
+        if ( HasMultipleSelection() )
+            return CalcAndSendEvent();
+
         evtType = wxEVT_COMMAND_LISTBOX_SELECTED;
         n = SendMessage(GetHwnd(), LB_GETCARETINDEX, 0, 0);
 
@@ -673,22 +670,8 @@ bool wxListBox::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
         return false;
     }
 
-    // retrieve the affected item
-    if ( n == wxNOT_FOUND )
-        return false;
-
-    wxCommandEvent event(evtType, m_windowId);
-    event.SetEventObject(this);
-
-    if ( HasClientObjectData() )
-        event.SetClientObject( GetClientObject(n) );
-    else if ( HasClientUntypedData() )
-        event.SetClientData( GetClientData(n) );
-
-    event.SetString(GetString(n));
-    event.SetInt(n);
-
-    return HandleWindowEvent(event);
+    // only send an event if we have a valid item
+    return n != wxNOT_FOUND && SendEvent(evtType, n, true /* selection */);
 }
 
 // ----------------------------------------------------------------------------