Solved

Docking problem

Posted on 2000-03-09
5
245 Views
Last Modified: 2010-04-04
I created a simple form (TForm) that includes just a TTreeView-Control. I fill this TTreeView within the Form with the following method:

procedure TChildSystemView.UpdateTree;
var
  node: TTreeNode;
  childNode: TTreeNode;
  i: Integer;
begin
  SystemTree.Items.Clear;
  node := SystemTree.Items.Add(nil, FLeagueSystem.SystemName);
  node.ImageIndex := 0;
  node.SelectedIndex := 0;
  if FLeagueSystem.NumberOfLeagues > 0 then
            for i := 1 to FLeagueSystem.NumberOfLeagues do begin
          childNode := SystemTree.Items.AddChild(node, FLeagueSystem.Leagues[i - 1].LeagueName);
      childNode.ImageIndex := 1;
      childNode.SelectedIndex := 1;
    end;
end;

This works fine. But this window is a dockable window within a parent Form and it is docked by default when I start the program. This works fine too. The problem is that when I undock the window and I re-dock it to the parent, all data within the tree is lost. What can I do?
0
Comment
Question by:klusi
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
5 Comments
 
LVL 3

Expert Comment

by:ckaneta
ID: 2601745
just a lame attempt: did you try calling update function from forms repaint event handler?
0
 

Author Comment

by:klusi
ID: 2601957
no, but this seems useless because I saw in the debugger that after the re-dock the tree's items-property was set to nil ! So it was empty and an update should give nothing.
0
 
LVL 10

Expert Comment

by:Lischke
ID: 2602040
Oh this looks as would the tree window be recreated which usually kills the content (although the VCL contains code to save the nodes to restore them later). Unfortunately, the Windows treeview is such a badly made thing you will get very often problems if you want to do something more than the absolute basics. I recommend that you save the tree content to a memory stream just before you change its dock state and restore it after that.

Another point, look at my home page www.lischke-online.de and download TreeNT, which is a free tree implementation which tries to get around many of the problems (though not always successfully).

Ciao, Mike
0
 
LVL 10

Expert Comment

by:Lischke
ID: 2652543
klusi?
0
 
LVL 10

Accepted Solution

by:
Lischke earned 100 total points
ID: 2758460
No reaction, then LOCK.
0

Featured Post

Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this tutorial I will show you how to use the Windows Speech API in Delphi. I will only cover basic functions such as text to speech and controlling the speed of the speech. SAPI Installation First you need to install the SAPI type library, th…
Creating an auto free TStringList The TStringList is a basic and frequently used object in Delphi. On many occasions, you may want to create a temporary list, process some items in the list and be done with the list. In such cases, you have to…
In this video, viewers will be given step by step instructions on adjusting mouse, pointer and cursor visibility in Microsoft Windows 10. The video seeks to educate those who are struggling with the new Windows 10 Graphical User Interface. Change Cu…
Monitoring a network: why having a policy is the best policy? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the enormous benefits of having a policy-based approach when monitoring medium and large networks. Software utilized in this v…
Suggested Courses
Course of the Month5 days, 17 hours left to enroll

626 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question