Solved

New component question

Posted on 2004-08-19
4
155 Views
Last Modified: 2010-04-05
OK, I'm a total novice at creating components.

I want to create a custom TTreeNode.   I really only need to add a few properties to the existing type.

In D6, I click on NEW COMPONENT and choose an ancestor class but TTreenode isn't listed, though TTreeView is (dont need that).

What method can I use to get the TTreenode code and inherit it so I can create my new TdsTreeNode?

Don
P.S. Marco Cantu's book shows how to use my new Ttreenode in the TreeView.Add function.
0
Comment
Question by:d32coder
  • 2
4 Comments
 
LVL 13

Accepted Solution

by:
BlackTigerX earned 50 total points
ID: 11841126
see... TreeNode is not a component, is just a class, so if you want to derive from that you have to do it from code:

something like this:

TdsTreeNode = class(TTreeNode)
private
  FYourNewProperty:Integer;
public
published
  YourNewProperty:Integer read FYourNewProperty write FYourNewProperty;
end;

then you could add a TdsTreeNode to a TreeView by code just as you would add a TreeNode, but referencing your TdsTreeNode type instead
0
 

Author Comment

by:d32coder
ID: 11841587
I plugged this snippet into my project...


TdsTreeNode = class(TTreeNode)
private
  FTag1: Integer;
  FTag2: Integer;
public
published
  Tag1: Integer read FTag1 write FTag1;
  Tag2: Integer read FTag2 write FTag2;
end;

On compile I get an error
  Published Field 'Tag1' not a class nor an interface type.
   
I wish I knew more about this.  

Don
0
 
LVL 11

Expert Comment

by:shaneholmes
ID: 11842048
property  Tag1: Integer read FTag1 write FTag1;
property   Tag2: Integer read FTag2 write FTag2;

Shane
0
 
LVL 13

Expert Comment

by:BlackTigerX
ID: 11842168
yes, sorry, I missed the property part

and it doesn't have to be in the published part, it can just be public
published is for components
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

Have you ever had your Delphi form/application just hanging while waiting for data to load? This is the article to read if you want to learn some things about adding threads for data loading in the background. First, I'll setup a general applica…
In my programming career I have only very rarely run into situations where operator overloading would be of any use in my work.  Normally those situations involved math with either overly large numbers (hundreds of thousands of digits or accuracy re…
You have products, that come in variants and want to set different prices for them? Watch this micro tutorial that describes how to configure prices for Magento super attributes. Assigning simple products to configurable: We assigned simple products…
This is a video describing the growing solar energy use in Utah. This is a topic that greatly interests me and so I decided to produce a video about it.

932 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

Need Help in Real-Time?

Connect with top rated Experts

17 Experts available now in Live!

Get 1:1 Help Now