TTreeView.OnCustomDrawItem

    TTreeNode *node;
    node = this->TreeView1->Items->Add(, "AAAA");
    TreeView1->Items->AddChild(node, "aaa1");
    TreeView1->Items->AddChild(node, "aaa2");
    TreeView1->Items->AddChild(node, "aaa3");

    node = this->TreeView1->Items->Add(, "BBBB");
    TreeView1->Items->AddChild(node, "aaa1");
    TreeView1->Items->AddChild(node, "aaa2");
    TreeView1->Items->AddChild(node, "aaa3");

循环插入节点

    TTreeNode *anode;
    for (int i = ; i < ; i++)
    {
        anode = this->TreeView1->Items->Add(, "Node" + String(i));
        TreeView1->Items->AddChild(anode, "aaa1");
        TreeView1->Items->AddChild(anode, "aaa2");
        TreeView1->Items->AddChild(anode, "aaa3");
    }

c++
/*
The following example shows how the OnCustomDrawItem event
handler draws items and lines of the tree view after the
OnCustomDraw event handler has filled in the background.
*/
void __fastcall TCustomDrawForm::TVCustomDrawItem(TCustomTreeView *Sender,
TTreeNode *Node, TCustomDrawState State, bool &DefaultDraw)
{
  TRect NodeRect;
/*
    If DefaultDraw it is true, any of the node's font
    properties can be changed. Note also that when
    DefaultDraw = True, Windows draws the buttons and
    ignores our font background colors, using instead the
    TreeView's Color property.
*/
if (State.Contains(cdsSelected))
    {
      TV->Canvas->Font->Assign(SelectedFontDialog->Font);
      TV->Canvas->Brush->Color = SelBkgColorDialog->Color;
    };

    DefaultDraw = FDefaultDrawItem;
/*
    DefaultDraw = False means you have to handle all the
    item drawing yourself, including the buttons, lines,
    images, and text.
*/
if (!DefaultDraw)
    {
//draw the selection rect.
if (State.Contains(cdsSelected))
      {
        NodeRect = Node->DisplayRect(True);
        TV->Canvas->FillRect(NodeRect);
      };
      NodeRect = Node->DisplayRect(False);

      if (None1->Checked)
//no bitmap, so paint in the background color.
      {
        TV->Canvas->Brush->Color = BkgColorDialog->Color;
        TV->Canvas->Brush->Style = FBrushStyle;
        TV->Canvas->FillRect(NodeRect);
      }
else
//don't paint over the background bitmap.
        TV->Canvas->Brush->Style = bsClear;

      NodeRect.Left = NodeRect.Left + (Node->Level * TV->Indent);
// NodeRect.Left now represents the left-most portion 
// of the expand button
      DrawButton(&NodeRect, Node); // See the CustomDraw demo

      NodeRect.Left = NodeRect.Left + TV->Indent + FButtonSize;
//NodeRect->Left is now the leftmost portion of the image.
      DrawImage(&NodeRect, Node->ImageIndex); // See the CustomDraw demo

      NodeRect.Left = NodeRect.Left + ImageList->Width;
//Now we are finally in a position to draw the text.

      TV->Canvas->TextOut(NodeRect.Left, NodeRect.Top, Node->Text);
    };
}

delphi

{
The following example shows how the OnCustomDrawItem event
handler draws items and lines of the tree view after the
OnCustomDraw event handler has filled in the background.
}
procedure TCustomDrawForm.TVCustomDrawItem(Sender: TCustomTreeView; Node: TTreeNode;
  State: TCustomDrawState; var DefaultDraw: Boolean);
var
  NodeRect: TRect;
begin
with TV.Canvas do
begin
{
    If DefaultDraw it is true, any of the node's font
    properties can be changed. Note also that when
    DefaultDraw = True, Windows draws the buttons and
    ignores our font background colors, using instead the
    TreeView's Color property.
}
if cdsSelected in State then
begin
      Font.Assign(SelectedFontDialog.Font);
      Brush.Color := SelBkgColorDialog.Color;
end;

    DefaultDraw := False; // FDefaultDrawItem;
{
    DefaultDraw = False means you have to handle all the
    item drawing yourself, including the buttons, lines,
    images, and text.
}
if not DefaultDraw then
begin
//draw the selection rect.
if cdsSelected in State then
begin
        NodeRect := Node.DisplayRect(True);
        FillRect(NodeRect);
end;
      NodeRect := Node.DisplayRect(False);

      if None1.Checked then
//no bitmap, so paint in the background color.
begin
        Brush.Color := BkgColorDialog.Color;
        Brush.Style := FBrushStyle;
        FillRect(NodeRect)
end
else
//don't paint over the background bitmap.
        Brush.Style := bsClear;

      NodeRect.Left := NodeRect.Left + (Node.Level * TV.Indent);
// NodeRect.Left now represents the left-most portion 
// of the expand button
      DrawButton(NodeRect, Node); // See the CustomDraw demo

      NodeRect.Left := NodeRect.Left + TV.Indent + FButtonSize;
//NodeRect.Left is now the leftmost portion of the image.
      DrawImage(NodeRect, Node.ImageIndex); // See the CustomDraw demo

      NodeRect.Left := NodeRect.Left + ImageList.Width;
//Now we are finally in a position to draw the text.

      TextOut(NodeRect.Left, NodeRect.Top, Node.Text);
end;
end;
end;