问题
I create a simple application and size of .apk generated by android studio is 1 MB, then i installed in android 2.3 version size increased to 3.48 MB , then i installed in android 5.0 version size increase to 5.48 MB.
My Question is only that why size of apk in increased in different version.
回答1:
When installing an APK in android system, what's installed is the DEX file. Which contains your code, resources etc compiled as binaries. Your dex is generally the same size of your apk, unless you have resources not compiled in assets.
Well, we all know that. What's not widelly spread is that android SAVES your original apk too. Perhaps for reinstalling in case of errors or for some other reasons.
That's why the amount of memory of our apps is the double in system. It's the sum of the size of the original apk and the installed dex.
来源：https://stackoverflow.com/questions/30782865/why-apk-size-increase-in-different-android-version