как сделать выделение в Listbox градиентом

TCanvas *pCanvas = ((TListBox *)Control)->Canvas;
if( State.Contains(odSelected) ) {
   GradientFillCanvas(this->Canvas, RGB(255, 128, 0), clGreen,
        Rect(12,32,23,123), gdVertical);
        pCanvas->FillRect(Rect);
        pCanvas->Brush->Color = RGB(12,32,23);
        pCanvas->Rectangle(1+23,0,2+44+1,32);
}

   GradientFillCanvas(this->Canvas, RGB(255, 128, 0), clGreen,
        /*System::*/Classes::Rect(12,32,23,123), gdVertical);

//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
  ListBox1->Style= lbOwnerDrawFixed;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::ListBox1DrawItem(TWinControl *Control, int Index, TRect &Rect,
          TOwnerDrawState State)
{
  TListBox* LB = (TListBox *)Control;
  LB->Canvas->Brush->Color = clWhite;
  LB->Canvas->FillRect(Rect);
 
  if(State.Contains(odSelected))
    {
        GradientFillCanvas(LB->Canvas, clYellow, clGreen,
                                       Rect, gdVertical);
    }
 
  String Text= LB->Items->Strings[Index];
  LB->Canvas->Brush->Style= bsClear;
  LB->Canvas->TextRect(Rect,Text);
}
//---------------------------------------------------------------------------

void __fastcall TForm1::ListBox1DrawItem(TWinControl *Control, int Index,
      TRect &Rect, TOwnerDrawState State)
{
   String Text= ListBox1->Items->Strings[Index];
   TRIVERTEX vert[2]= {
    {Rect.left,Rect.top, 0xff00, 0xff00, 0x0000, 0x0000},
    {Rect.right,Rect.bottom, 0x0000, 0xff00, 0xff00, 0x0000}} ;
   GRADIENT_RECT gRect = {0,1};
   ListBox1->Canvas->Brush->Style= bsSolid; 
   if (State.Contains(odSelected))  {
  ListBox1->Canvas->Brush->Style= bsClear;
  GradientFill(ListBox1->Canvas->Handle,vert,2,&gRect,1,GRADIENT_FILL_RECT_H);
 
   } else  {
    ListBox1->Canvas->Brush->Style= bsSolid;
    ListBox1->Canvas->FillRect(Rect);
   }
   ListBox1->Canvas->Font->Color = clBlack; 
   ListBox1->Canvas->TextRect(Rect,0,Rect.top,Text);
}