How to: Clear the Undo Stack

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The latest version of this topic can be found at How to: Clear the Undo Stack.

The following procedure below explains how to clear the undo stack.

To clear the undo stack

1. To clear the undo stack use the IOleUndoManager::DiscardFrom method. The following is an example of this:

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   HRESULT CCmdWindow::ClearUndoStack()  
   {  
     HRESULT hr = S_OK;  
   
     if (m_pUndoMgr == NULL)  
       {  
       IfFailGo(m_pTextLines->GetUndoManager(&m_pUndoMgr));  
       ASSERT(m_pUndoMgr != NULL, "",;);  
       }  
   
     IfFailGo(m_pUndoMgr->DiscardFrom(NULL));  
   
   Error:  
     return hr;  
   }  
   
   

How to: Implement Undo Management