//屏蔽右键菜单
procedure TForm1.ApplicationEvents1Message(var Msg: tagMSG;
  var Handled: Boolean);
begin
  with Msg do
  begin
    if not IsChild(WebBrowser1.Handle, hWnd) then Exit;
    Handled := (message= WM_RBUTTONDOWN) or(message= WM_RBUTTONUP) or(message= WM_CONTEXTMENU);
  end;
end;

//替换右键菜单
procedure TForm1.ApplicationEvents1Message(var Msg: tagMSG;
  var Handled: Boolean);
var pt: TPoint;
begin
  if IsChild(WebBrowser1.Handle, Msg.Hwnd) and ((Msg.Message = WM_RBUTTONDOWN) or(Msg.Message = WM_RBUTTONUP)) then
  begin
    GetCursorPos(pt);  //得到光标位置
    PopupMenu1.Popup(pt.X, pt.Y);   //弹出popupmenu1的菜单
    Handled:=True;
  end;
end;