android - Drawable 占用的内存是否比 Bitmap 少？

Question

我是 Android 新手，刚来这里。

我只知道 Bitmap 逐像素存储图像并且不进行任何压缩。

Drawable和Bitmap一样吗？
或者
同样的图片文件，Drawable 比 Bitmap 占用内存少？

感谢任何回复。

Answer 1

位图是一个Drawable。 Drawable 不一定是位图。就像所有的拇指都是手指，但并非所有的手指都是拇指。

The API dictates :

Though usually not visible to the application, Drawables may take a variety of forms:

• Bitmap: the simplest Drawable, a PNG or JPEG image.
• Nine Patch: an extension to the PNG format allows it to specifyinformation about how to stretch it and place things inside of it.
• Shape: contains simple drawing commands instead of a raw bitmap,allowing it to resize better in some cases.
• Layers: a compound drawable, which draws multiple underlyingdrawables on top of each other.
• States: a compound drawable that selects one of a set of drawablesbased on its state.
• Levels: a compound drawable that selects one of a set of drawablesbased on its level.
• Scale: a compound drawable with a single child drawable, whoseoverall size is modified based on the current level.