android屏幕适配

详情请看api官方文档：

http://developer.android.com/guide/practices/screens_support.html

简要看下面的说明：

A set of six generalized densities:

ldpi (low) ~120dpi

mdpi (medium) ~160dpi

hdpi (high) ~240dpi

xhdpi (extra-high) ~320dpi

xxhdpi (extra-extra-high) ~480dpi

xxxhdpi (extra-extra-extra-high) ~640dpi



再看下面密度分析：

To create alternative bitmap drawables for different densities, you should follow the 3:4:6:8:12:16 scaling ratio between the six generalized densities. For example, if you have a bitmap drawable that’s 48x48 pixels for medium-density screens, all the different sizes should be:


36x36 (0.75x) for low-density

48x48 (1.0x baseline) for medium-density

72x72 (1.5x) for high-density

96x96 (2.0x) for extra-high-density

180x180 (3.0x) for extra-extra-high-density

192x192 (4.0x) for extra-extra-extra-high-density (launcher icon only; see note above)