CODEWITHSUNDEEP
delphidelphi-xe2virtualtreeviewtvirtualstringtree
RBA
RBA

Reputation: 12584

TVirtualStringTree - add object instead of record

I have a TVirtualStringTree(version 5.2.2) and I need to add to it's nodes objects instead of records.

I have already looked at the answers provided on the question: Delphi, VirtualStringTree - classes (objects) instead of records but they are not working.

Objects I want to add to the tree's nodes are like 

  TNodeElem = class
  public
    LineTimeS, LogMessage, MethName: String;
    LineDate,LineTime: TDateTime;
    LineDateTime: TDateTime;
    ElemType: TLogLineType;//ordinal type
....
  end;

these nodes are added to a TObjectList:

FObjLst.Add(lNode);

and added to the tree:

var iPos: Integer;
    lNode: PVirtualNode;
    ldata: TNodeElem;
begin
  FTreeView.BeginUpdate;
  for iPos := 0 to FObjLst.Count -1 do
  begin
   lNode := FTreeView.AddChild(nil);
   lData := TNodeElem(FObjLst[iPos]);
   FTreeView.getNodeData(lNode)^ := lData;//E2015 Operator not aplicable to this operand type
   FTreeView.ValidateNode(lNode,False);
  end;
  FTreeView.EndUpdate;
end;

procedure VSTGetText(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex;
    TextType: TVSTTextType; var CellText: UnicodeString);
var
 Data: TNodeElem;
begin
 Data := FTreeView.GetNodeData(Node);
 CellText := Data.LogMessage;
end;

I get an E2015 Operator not aplicable to this operand type error . It is probably something extremely simple what I'm missing here...

I know I can add it as a record with an object member like:

TNode = record
 obj: TMyObject;
end;

but I want to understand what I'm doing wrong.

Upvotes: 5

Views: 1258

Answers (2)

Christophe Fardeau
Christophe Fardeau

Reputation: 224

Another way is to store index of object in Tlist. Then you don't work by reference. It's more easiest to check bad reference.

procedure TForm1.Button2Click(Sender: TObject);
var i : Integer;
begin
  for i := 0 to Pred(Mylist.count) do
    VirtualStringTree1.AddChild(nil, pInteger(i));
end;

procedure TForm1.VirtualStringTree1GetNodeDataSize(Sender: TBaseVirtualTree; var NodeDataSize: Integer);
begin
  NodeDataSize := SizeOf(integer);
end;

procedure TForm1.VirtualStringTree1GetText(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex;
  TextType: TVSTTextType; var CellText: string);
var i : Integer;
begin
  if Node = nil then Exit;
  CellText := 'Unknown';
  i := pInteger(Sender.GetNodeData(node))^;
  if (i >= 0) and (i < Mylist.Count) then begin
    if Assigned(MyList[i]) then
      Celltext := TmyObject(MyList[i]).MyText;
  end;
end;

Upvotes: 0

kami
kami

Reputation: 1468

function AddItem(Item: TNodeElem): PVirtualNode;
begin
  Result := FTreeView.InsertNode(nil, amAddChildLast, Item);
end;

function GetItem(Node: PVirtualNode): TNodeElem;
var
  NodeData: Pointer;
begin
  Result := nil;
  if not Assigned(Node) then
    exit;
  NodeData := FTreeView.GetNodeData(Node);
  if Assigned(NodeData) then
    Result := TNodeElem(NodeData^);
end;

Upvotes: 5

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