function TfmTree.BuildTree: boolean;
Var
  TreeViewItem, TreeViewItemParent: TTreeViewItem;
begin
// 0 - id, 1- parent, 2 - name
// fmTree.qTree.SQL.Text := 'select id, parent, name from regions order by parent';

  if not qTree.Active then qTree.Open;
  if qTree.RecordCount <= 0 then exit(false);
  qTree.First;
  TreeView1.Clear;
  TreeView1.BeginUpdate;


  try
    while not qTree.Eof do
    begin
      if VarIsNull(qTree.Fields[1].Value) then
      begin
        AddChild(nil, qTree.Fields[2].Value, qTree.Fields[0].Value, TreeView1);// создаем root (нулевые)  TTreeViewItem`ы

      end
      else
      begin
        TreeViewItem := ItemByTag(qTree.Fields[1].Value);// ищем родителя, у которого tag = Fields[1]
        AddChild(TreeViewItem, qTree.Fields[2].Value, qTree.Fields[0].Value, TreeView1);// добавляем дочерний TTreeViewItem
      end;// else

      qTree.Next;
    end;// while

  finally
    TreeView1.EndUpdate;

  end;
  result := True;
end;

function TfmTree.ItemByTag(id: integer): TTreeViewItem;
var
  Item: TTreeViewItem;
  I: Integer;
begin
// взял как пример на основе ItemByText из исходников FMX
  Result := nil;
  for I := 0 to Pred(TreeView1.GlobalCount) do
  begin
    Item := TreeView1.ItemByGlobalIndex(I);
    if Item.Tag = id then
      Exit(Item);
  end;
end;

Function TfmTree.ItemByTag(id_parent: integer): TTreeViewItem;
var
  aItem: TTreeViewItem;
begin
  aItem := nil;

  TreeView1.EnumControls(
    function(Control: TControl): TEnumControlsResult
    begin
      if (Control is TTreeViewItem) then
      begin
        if TTreeViewItem(Control).Tag = id_parent then
        begin
          aItem  := TTreeViewItem(Control);
          Result := TEnumControlsResult.Discard;
        end
        else
          Result := TEnumControlsResult.Continue;
      end
      else
        Result := TEnumControlsResult.Continue;
    end);

  Result := aItem;
end;

function BuildTree(TreeView1: TTreeView; qTree: TUniQuery): boolean;
Var
  TreeViewItem: TTreeViewItem;
begin
  qTree.close;
  qTree.Open;// select id, parent, name
  if qTree.RecordCount <= 0 then exit(false);
  qTree.First;
  TreeView1.Clear;
  TreeView1.BeginUpdate;

  try
    while not qTree.Eof do
    begin
      if VarIsNull(qTree.Fields[1].Value) then
        AddChild(nil, qTree.Fields[2].Value, qTree.Fields[0].Value, TreeView1)
      else
      begin
        TreeViewItem := ItemByTag(TreeView1, qTree.Fields[1].Value);
        TreeViewItem.Name := 'TreeViewItem' + qTree.Fields[1].AsString;
        TreeViewItem.Height := 40;
        AddChild(TreeViewItem, qTree.Fields[2].Value, qTree.Fields[0].Value, TreeView1);
      end;// else

      qTree.Next;
    end;// while

  finally
    TreeView1.EndUpdate;

  end;
  result := True;
end;


procedure AddChild(parent: TFMXObject; Text: string; key_val: integer; TreeView: TTreeView);
Var
 TreeViewItem: TTreeViewItem;
 ALabel: TLabel;
begin
  TreeViewItem := TTreeViewItem.Create(TreeView);
  TreeViewItem.Name := 'TreeViewItem' + key_val.ToString;
  TreeViewItem.StyleLookup := 'treeviewitemstyle';

  if not assigned(parent) then
    TreeViewItem.parent := TreeView
  else
    TreeViewItem.Parent := parent;

  ALabel := TLabel.create(TreeViewItem);
  ALabel.Parent := TreeViewItem;
  ALabel.Align := TAlignLayout.Right;
  ALabel.TextSettings.HorzAlign := TTextAlign.Trailing;
  ALabel.Text := key_val.ToString;
//  ALabel.Padding.Right := 5;

  TreeViewItem.Text:= text;
  TreeViewItem.Tag := key_val;
end;


Function ItemByTag(TreeView1: TTreeView; id_parent: integer): TTreeViewItem;
var
  aItem: TTreeViewItem;
begin
  aItem := nil;

  TreeView1.EnumControls(
    function(Control: TControl): TEnumControlsResult
    begin
      if (Control is TTreeViewItem) then
      begin
        if TTreeViewItem(Control).Tag = id_parent then
        begin
          aItem  := TTreeViewItem(Control);
          Result := TEnumControlsResult.Discard;
        end
        else
          Result := TEnumControlsResult.Continue;
      end
      else
        Result := TEnumControlsResult.Continue;
    end);

  Result := aItem;
end;


Function FindItemByText(val: String; TreeView: TTreeView): TTreeViewItem;
var
  aItem: TTreeViewItem;
begin
  aItem := nil;
  val := AnsiUpperCase(val);

  TreeView.EnumControls(
    function(Control: TControl): TEnumControlsResult
    begin
      if (Control is TTreeViewItem) then
      begin
        if ContainsText((TTreeViewItem(Control).Text), val) then
        begin
          aItem  := TTreeViewItem(Control);
          Result := TEnumControlsResult.Discard;
        end
        else
          Result := TEnumControlsResult.Continue;
      end
      else
        Result := TEnumControlsResult.Continue;
    end);

  Result := aItem;
end;


procedure SelectItemByText(const sText: String; TreeView: TTreeView);
var
 TreeViewItem: TTreeViewItem;
begin
  TreeViewItem := FindItemByText(sText, TreeView);
  if assigned(TreeViewItem) then
    TreeViewItem.Select;
end;

function GetPathFromTreeViewItem(AItem: TTreeViewItem): String;
begin
  if AItem = nil then exit('nothing selected');

  while Assigned(AItem) and (AItem is TTreeViewItem) do
  begin
    Result := AItem.Text + '\' + Result;
    AItem := TTreeViewItem(AItem.ParentItem);
  end;

  Delete(Result, Length(Result), 1);
end;