一、android各个版本分布状况:
https://developer.android.com/about/dashboards/
二、android 4.4,代号Kitkat(奇巧巧克力), api 级别 19
https://developer.android.com/about/versions/kitkat
三、android 5系列,代号Lollipop(棒棒糖),api 级别 21-22
https://developer.android.com/about/versions/lollipop
四、android 6.0(M),代号Marshmallow(棉花糖), api 级别 23,
https://developer.android.com/about/versions/marshmallow/
五、android 7.0系列, 代号Nougat (牛轧糖),api 级别 24
https://developer.android.com/about/versions/nougat/
六、android 8,代号Oreo(奥利奥), api级别 27
https://developer.android.com/about/versions/oreo/android-8.0
七、android 9,代号Pie(馅饼), api级别 29