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Adding a new property (String) to a TreeNode.

Greetings,
How can I add a new property to a TreeNode object.
I must store additional information (string) for each node in a TreeView.
Thank you,
Tzigi

Stefaan

You can add whatever information to a TTreeNode using the data property :

The following code defines a record type of TMyRec and a record pointer type of PMyRec.

type
PMyRec = ^TMyRec;
TMyRec = record
FName: string;
LName: string;
end;

Assuming these types are used, the following code adds a node to TreeView1 as the last sibling of a specified node. A TMyRec record is associated with the added item. The FName and LName fields are obtained from edit boxes Edit1 and Edit2. The Index parameter is obtained from edit box Edit3. The item is added only if the Index is a valid value.

procedure TForm1.Button1Click(Sender: TObject);

var
MyRecPtr: PMyRec;
TreeViewIndex: LongInt;
begin
New(MyRecPtr);
MyRecPtr^.FName := Edit1.Text;
MyRecPtr^.LName := Edit2.Text;
TreeViewIndex := StrToInt(Edit3.Text);
with TreeView1 do
begin
if Items.Count = 0 then
Items.AddObject(nil, 'Item' + IntToStr(TreeViewIndex), MyRecPtr)
else if (TreeViewIndex < Items.Count) and (TreeViewIndex >= 0) then

Items.AddObject(Items[TreeViewIndex], 'Item' + IntToStr(TreeViewIndex), MyRecPtr);
end;
end;

tzigi

ASKER

Thank you for your quick reply.
I know how to use the Data property, but my question was related to the concept of adding a property to an object that is dependent in other objects like in this situation the TreeView.
Can I change the TreeNode without changing the TreeView ?
Best Regards,
Tzigi.

ASKER CERTIFIED SOLUTION

MarcG

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tzigi

ASKER

Thank you Marc,
I'll try it.

Stefaan

Hi again,

Well you could do it of course, but it seems to be pretty hard. You would have to subclass the TTreeNode and the TTreeNodes, and apparently some stuff is declared as Private variables, so it seems to be pretty hard to get it working correctly. You would even have to subclass some treeview aspects. So you will end up with your own derived TTreeView, TTreeNodes and TTreeNode objects.

Best regards,

Stefaan

Stefaan

Damn, too late with posting my comment, Marc pressed the post button before I did, but what he actually says is exactly the same thing.

tzigi

ASKER

Thank you All.