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Dear Support,

I created a tree which should support sorting, but when the header is clicked I get into this assert:

bool CExtTreeGridDataProvider::SortOrderGet(
	CExtGridDataSortOrder & _gdso,
	bool bColumns // true = sort order for columns, false - for rows
	) const
{
	ASSERT_VALID( this );
	_gdso;
	bColumns;
	// this method must never be invoked
	ASSERT( FALSE );
	return true;
}

Obviously something is missing, but what?

Thanks,
Ron.

Thank you for reporting the tree item hiding problem. It was not difficult to fix but was quite hard to find it. Please update the source code for the following method:

void CExtTreeGridCellNode::TreeNodeHiddenSet(
      CExtTreeGridDataProvider & _DP,
      bool bHide
      )
{
      ASSERT_VALID( this );
      ASSERT_VALID( (&_DP) );
      ASSERT_KINDOF( CExtTreeGridDataProvider, (&_DP) );
bool bHidden = TreeNodeHiddenGet();
      if( ( bHidden && bHide ) || ( (!bHidden) && (!bHide) ) )
            return;
      if( bHide )
      {
            if( TreeNodeIsDisplayed() )
            {
                  ULONG nOffset = TreeNodeCalcOffset( true, false );
                  if( nOffset != ULONG(-1L) )
                  {
                        ASSERT( _DP.m_arrGridVis[ nOffset ] == this );
                        INT nCountToRemove = _ContentWeight_Get( true );
                        _DP.m_arrGridVis.RemoveAt( nOffset, nCountToRemove + 1 );
                        CExtTreeGridCellNode * pNodeParent = TreeNodeGetParent();
                        if( pNodeParent != NULL )
                        {
                              ASSERT_VALID( pNodeParent );
                              pNodeParent->_ContentWeight_Decrement( nCountToRemove + 1, true );
                        }
                  }
            }
            ModifyStyleEx( __EGCS_EX_HIDDEN_TREE_NODE, 0 );
      } // if( bHide )
      else
      {
            ModifyStyleEx( 0, __EGCS_EX_HIDDEN_TREE_NODE );
            if( TreeNodeIsDisplayed() )
            {
                  ULONG nOffset = TreeNodeCalcOffset( true, false );
                  if( nOffset != ULONG(-1L) )
                  {
                        INT nCountToInsert = _ContentWeight_Get( true );
                        _DP.m_arrGridVis.InsertAt( nOffset, NULL, nCountToInsert + 1 );
                        _DP.m_arrGridVis.SetAt( nOffset, this );
                        nOffset ++;
                        _Content_FillVisibleArray( _DP.m_arrGridVis, nOffset );
                        CExtTreeGridCellNode * pNodeParent = TreeNodeGetParent();
                        if( pNodeParent != NULL )
                        {
                              ASSERT_VALID( pNodeParent );
                              pNodeParent->_ContentWeight_Increment( nCountToInsert + 1, true );
                        }
                  }
            }
      } // else from if( bHide )
}

Thanks - problem solved

Now, what about the original question of this thread?...

It would be easier for us to regard the root question in this thread as a feature request and implement tree sorting on a column header click as built-in behavior of the CExtTreeGridWnd class.

Can you please explain what I should do so that the clicking of the column header will call the ItemSortChildren function?
As I explained it crashes now, and you say there is a ItemSortChildren function, but it is not utilized when the header is clicked.

The CExtTreeGridWnd::ItemSortChildren() method sorts child items of the specified tree item (root or any other). This method sorts only the children of one level and does not affect deeper level items. It’s possible to code some recursive method based on CExtTreeGridWnd::ItemSortChildren() method for any custom sorting of all the tree grid or its particular branches. But the CExtTreeGridWnd class does not support any kind of automatic sorting action as a reaction to the mouse click on some header cell at top/bottom because we have no idea which rows to sort or not in according to particular customer needs.

Dear Support,

How do I attach this to the existing columns header sorting mechanism? This is a tree grid hybrid, so when the user presses the columns header I need to sort according to the column the user pressed. This is when I get the assert.

Regards,

Ron,