can't add new treenode

[sydenis]

I have a code that removes child nodes from a selected TTreeNode and adds there a new child nodes

Code: Pascal  [Select][+][-]

1. Node.DeleteChildren;
2. Node.TreeNodes.AddChild(Node, 'Child 1');
3. Node.TreeNodes.AddChild(Node, 'Child 2');

As a result, the old nodes disappear, but no new ones appear. Why?

[jamie]

What OS ?

[sydenis]

win10 + lazarus 4.4

[jamie]

Try removing treenodes in the mix.

Node.addchild(..........)

[sydenis]

Node.addchild(..........)

there is no such method in lazarus)

[Martin_fr]

Code: Pascal  [Select][+][-]

1. procedure TTreeNode.DeleteChildren;
2. begin
3.   if Owner<>nil then Owner.ClearCache;
4.   Collapse(true);
5.   HasChildren := False;
6. end;
7.  

Have you tried to expand the nodes?

[sydenis]

Yes. The node has an icon to expand, but nothing happens when clicked. If I remove the line

Code: Pascal  [Select][+][-]

1. Node.DeleteChildren;

from the code then nodes are added normally

[Martin_fr]

Then maybe you also need to set
  HasChildren := true;

If so (not tested): Strange, maybe a bug, don't know what is/was indented.

[jamie]

I just ran a test on the trunk because that is what's next to me atm and I can't varify your findings, it all works as it should.

I am wondering if maybe you have implemented some of the events and maybe have interfered with the operation of the OnAdditon for example and related items, like OnDelete etc.

I can upload the app I used to test.

Jamie

[jamie]

Test app

[sydenis]

I am wondering if maybe you have implemented some of the events and maybe have interfered with the operation of the OnAdditon for example and related items, like OnDelete etc.

Yes. I override the expand method in the descendant of TreeView
and added the deletion of old children there so that the latest information is displayed when reopening.
There seems to be a problem here

[jamie]

I don't why you would to an override but maybe you didn't property call the inherited code?

Jamie

[sydenis]

I moved Node.DeleteChildren to the Collapse method of descendant. Everything is fine now