/*
This example requires two buttons, three TEdits, a label and
a populated TreeView.  The following code defines a record
type of TMyRec and a record pointer type of PMyRec.
*/
typedef struct MyRec
{
  AnsiString FName, LName;
} TMyRec;

typedef TMyRec* PMyRec;
/*
Assuming these types are used, the following code adds a
node to TreeView1 as the last sibling of the node specified
by the Index.  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.
*/

#include <memory>       //for STL auto_ptr class

void __fastcall TForm1::Button1Click(TObject *Sender)
{
  int TreeViewIndex;
  TTreeNodes* items;

  // MyRecPtr will be added as an object to the treeview, so it's OK for MyRecPtr to be deleted in this proc.
  std::auto_ptr<TMyRec> MyRecPtr(new TMyRec);
  MyRecPtr->FName = Edit1->Text;
  MyRecPtr->LName = Edit2->Text;
  TreeViewIndex = StrToInt(Edit3->Text);
  items = TreeView1->Items;
  if (items->Count == 0)
    items->AddObject(NULL, "Item" + IntToStr(TreeViewIndex), MyRecPtr.get());
  else if ((TreeViewIndex < items->Count) && (TreeViewIndex >= 0))
    items->AddObject(
      items->Item[TreeViewIndex],
      "Item" + IntToStr(TreeViewIndex) + "after" + items->Item[TreeViewIndex]->Text,
      MyRecPtr.get());
}
/*
After an item containing a TMyRec record has been added, the
following code retrieves the FName and LName values
associated with the item and displays the values in a label.
*/
void __fastcall TForm1::Button2Click(TObject *Sender)
{
  if (TreeView1->Selected->Data != NULL)
    Label1->Caption = PMyRec(TreeView1->Selected->Data)->FName + " " +
                 PMyRec(TreeView1->Selected->Data)->LName;
}

TTreeNode *currentNode = NULL;

void __fastcall TForm1::Button3Click(TObject *Sender)
{
//  PMyRec  MyRecPtr;
  TTreeNodes* items;

//  MyRecPtr = new TMyRec;
  // MyRecPtr will be added as an object to the treeview, so it's OK for MyRecPtr to be deleted in this proc.
  std::auto_ptr<TMyRec> MyRecPtr(new TMyRec);
  MyRecPtr->FName = Edit1->Text;
  MyRecPtr->LName = Edit2->Text;
  items = TreeView1->Items;
  if (currentNode != NULL)
    items->AddObject(currentNode, Edit4->Text + " after " + currentNode->Text, MyRecPtr.get());
}

void __fastcall TForm1::TreeView1MouseDown(TObject *Sender, TMouseButton Button,
      TShiftState Shift, int X, int Y)
{
  THitTests HT;
  if (Sender->ClassNameIs("TTreeView"))
  {
    TTreeView *pTV = dynamic_cast<TTreeView *>(Sender);
    HT = pTV->GetHitTestInfoAt(X,Y);
    if (HT.Contains(htOnItem))
      currentNode = pTV->GetNodeAt(X,Y);
  }
}

void __fastcall TForm1::Button4Click(TObject *Sender)
{
  if (currentNode != NULL)
    Label2->Caption = IntToStr(currentNode->AbsoluteIndex);
}

{
This example requires three buttons, four TEdits, two labels
and a populated TreeView.  The following code defines a
record type of TMyRec and a record pointer type of PMyRec.
}
type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Edit1: TEdit;
    TreeView1: TTreeView;
    Label2: TLabel;
    Label3: TLabel;
    Button3: TButton;
    Edit4: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
  type
  PMyRec = ^TMyRec;
  TMyRec = record
    FName: string;
    LName: string;
  end;


var
  Form1: TForm1;

implementation

{$R *.dfm}

{
Assuming these types are used, the following code adds a
node to TreeView1 as the last sibling of the selected node.
A TMyRec record is associated with the added item. The FName
and LName fields are obtained from edit boxes Edit1 and
Edit2.
}
procedure TForm1.Button1Click(Sender: TObject);
var
  MyRecPtr: PMyRec;
  TreeViewIndex: LongInt;
begin
  New(MyRecPtr);
  MyRecPtr^.FName := Edit1.Text;
  MyRecPtr^.LName := Edit2.Text;
  with TreeView1 do
  begin
    TreeViewIndex := Selected.AbsoluteIndex;
    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;
{
After an item containing a TMyRec record has been added, the
following code retrieves the FName and LName values
associated with the item and displays the values in a label.
} 
procedure TForm1.Button2Click(Sender: TObject);
begin
  if (TreeView1.Selected.Data <> nil) then { query only works on new nodes }
    Edit3.Text := PMyRec(TreeView1.Selected.Data)^.FName + ' ' +
                  PMyRec(TreeView1.Selected.Data)^.LName;
end;
procedure TForm1.Button3Click(Sender: TObject);
begin
  Edit4.Text := IntToStr(TreeView1.Selected.AbsoluteIndex);
end;