我想提请位图上MyPositionOverlay绘制方法扩展覆盖类，但我得到这个错误：该方法的getResource（）是未定义的类型MyPositionOverlay

I want to draw bitmap on draw method in MyPositionOverlay extends Overlay class but I get this error: The method getResource() is undefined for the type MyPositionOverlay

我哪里错了？

下面是code形式的抽奖方式：

Here is code form draw method:

  Bitmap bmp = BitmapFactory.decodeResource(getResource(), R.drawable.icon); 
     canvas.drawBitmap(bmp, screenPts.x, screenPts.y-50, null);

感谢

推荐答案

在getResources（）方法不是覆盖类的成员。 getResources（）是Context类中的一员。你需要通过一个上下文的引用您的覆盖子类，以便它可以加载绘制资源：

The getResources() method is not a member of the Overlay class. getResources() is a member of the Context class. You need to pass a reference of a Context to your Overlay subclass so that it can load the Drawable resource:

Bitmap bmp = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon); 

您也不想加载一个位图在绘制方法，因为它是非常占用大量内存，并会减慢你的应用程序，你应该保存的位图的成员变量在覆盖的构造函数，以便它只是变得加载一次。

You also don't want to load a bitmap in your draw method as it is very memory intensive and will slow down your application, you should save a member variable of the bitmap in the constructor of the overlay so that it only gets loaded once.