车载导航系统中，Draw 是实现地图描画和控制的主要模块。地图和mark 的描画工作都由Draw 来实现。具 有诱导方向表示功能的诱导线，我们将其作为一种特殊的mark 来描画。其主要功能分为：诱导线的表示控制、诱导线的数据 取得、诱导线的描画实行。

In vehicle navigation system, Draw is the main part of the map drawing and control. Map and mark drawing is realized by Draw. The induced wire shows the direction. We use it as a special mark drawing. Its main functions are induced wire control, data acquisition of induced wire and induced wire drawing practice.