Command Bars - Access Violation with CXTPControlComboBox

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Access Violation with CXTPControlComboBox

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Category: Codejock Products
Forum Name: Command Bars
Forum Description: Topics Related to Codejock Command Bars
URL: http://forum.codejock.com/forum_posts.asp?TID=8859
Printed Date: 03 July 2024 at 3:55am
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Topic: Access Violation with CXTPControlComboBox

Posted By: Anna2004
Subject: Access Violation with CXTPControlComboBox
Date Posted: 22 November 2007 at 5:14am

Hi,

I am using CXTControlComboBox in my toolbar.

First, I declare it as CXTControlComboBox m_skins in MainFrame.h.

And in MainFrame.cpp, I add the strings to this combobox in the following way:

int CMainFrame::OnCreateControl(LPCREATECONTROLSTRUCT lpCreateControl)
{
if (lpCreateControl->nID == ID_MY_TOOL_SKIN)
{
  m_skins.SetWidth(60);
  m_skins.SetDropDownListStyle(TRUE);
  m_skins.AddString(_T("Skin1"));
  m_skins.AddString(_T("Skin2"));

lpCreateControl->pControl = &m_skins;
return TRUE;
}
return FALSE;
}

I got Access Violation when I exit the application, when it came to destructor of CMainFrame.

Then I looked through the examples and find out that I should use a pointer, like this:

in MainFrame.h

CXTControlComboBox* m_skins;

in MainFrame.cpp

int CMainFrame::OnCreateControl(LPCREATECONTROLSTRUCT lpCreateControl)
{
if (lpCreateControl->nID == ID_MY_TOOL_SKIN)
{
  m_skins = (CXTPControlComboBox*)CXTPControlComboBox::CreateObject();
  m_skins->AddString(_T("Skin1"));
  m_skins->AddString(_T("Skin2"));
  m_skins->SetDropDownWidth(150);
  lpCreateControl->pControl = m_skins;
  return TRUE;
}
return FALSE;
}

Could someone explain for me why?

Thanks for your help

Replies:

Posted By: jimmy
Date Posted: 22 November 2007 at 5:32am

All Controls are destroy by CommandBars Manager.
If you use a member variable, the CommandBars Manager will destroy the control and also the member variable will be destroyed. (double destroy of a object).

Jimmy

Posted By: Anna2004
Date Posted: 22 November 2007 at 5:51am

I see. Thanks.

But the code (member variable not using pointer) worked fine with VS2003 and XtremeToolkid Pro 9.8. Why is that?