在Android中的非Activity类中实现Canvas(implement Canvas in non

在Android中的非Activity类中实现Canvas(implement Canvas in non-Activity class in Android)

我正在开发一个扩展Map Activity类的项目。这个项目只能有这个活动。

我想实现Canvas，但是据我所知，它取决于Activity类，这已被证明是一个障碍。

我的问题是如何绕过这个问题？ 有没有办法在画布上绘制减去Activity类的方法？ 欢迎任何想法。 谢谢

I am working on a project that extends the Map Activity class once.This project can only have this one activity.

I would like to implement the Canvas however since from my knowledge it depends on the Activity class, this has proven to be a road block.

My query is how can I bypass this issue? Is there a way I can actually draw on a canvas minus the Activity class? Any ideas would be gladly welcome. Thanks

最满意答案

您可以像这样获取Canvas的实例：

Paint p = new Paint(); ... Bitmap bitmap = Bitmap.createBitmap(100, 100, Config.ARGB_8888); Canvas canvas = new Canvas(bitmap); canvas.drawArc(new RectF(10, 10, 90, 90), 0, 270, false, p);

我在一个不是Activity的BroadcastReceiver中使用这个片段，你可以看到我在它上画画。

You can get an instance of Canvas like this:

Paint p = new Paint(); ... Bitmap bitmap = Bitmap.createBitmap(100, 100, Config.ARGB_8888); Canvas canvas = new Canvas(bitmap); canvas.drawArc(new RectF(10, 10, 90, 90), 0, 270, false, p);

I use this snippet in a BroadcastReceiver that is not an Activity and you can see that I draw on it.