【Android】玩转命令行工具-aapt2

aapt2即Android Asset Packaging Tool，是Android中的资源打包工具，另外还有个过时的aapt。aapt2是Android API 26.0.2才出现的，在Android SDK中的位置为android_sdk/build-tools/version/aapt2。

aapt2编译资源分为两步，第一步编译，分别编译每个资源为一个独立的二进制文件，文件后缀为.flat；第二步链接，合并上一步编译出来的所有的二进制文件为一个文件，这也是支持增量编译的基础。

aapt2的编译和链接让AndroidStudio或者Android.mk执行就好了，对于一个apk来说，aapt2还可以dump其中的资源信息，如下例子所示。

$ ./build-tools/28.0.3/aapt2 dump Animal.apk 
Binary APK
Package name=a.b.animal id=7f
  type color id=05 entryCount=1
    resource 0x7f050000 color/color_default
      () #ff0000ff
  type drawable id=02 entryCount=4
    resource 0x7f020000 drawable/animal
      () (file) res/drawable/animal.jpg
    resource 0x7f020001 drawable/ic_launcher_background
      () (file) res/drawable/ic_launcher_background.xml type=XML
    resource 0x7f020002 drawable/ic_launcher_foreground
      (v24) (file) res/drawable-v24/ic_launcher_foreground.xml type=XML
    resource 0x7f020003 drawable/ic_launcher_foreground_1
      (v24) (file) res/drawable-v24/ic_launcher_foreground_1.xml type=XML
  type id id=08 entryCount=4
    resource 0x7f080000 id/image_animal
      () (id)
    resource 0x7f080001 id/theme_default
      () (id)
    resource 0x7f080002 id/theme_dog
      () (id)
    resource 0x7f080003 id/theme_monkey
      () (id)
  type layout id=04 entryCount=1
    resource 0x7f040000 layout/layout_main
      () (file) res/layout/layout_main.xml type=XML
  type mipmap id=03 entryCount=2
    resource 0x7f030000 mipmap/ic_launcher
      (mdpi-v4) (file) res/mipmap-mdpi-v4/ic_launcher.png type=PNG
      (hdpi-v4) (file) res/mipmap-hdpi-v4/ic_launcher.png type=PNG
      (xhdpi-v4) (file) res/mipmap-xhdpi-v4/ic_launcher.png type=PNG
      (xxhdpi-v4) (file) res/mipmap-xxhdpi-v4/ic_launcher.png type=PNG
      (xxxhdpi-v4) (file) res/mipmap-xxxhdpi-v4/ic_launcher.png type=PNG
      (anydpi-v26) (file) res/mipmap-anydpi-v26/ic_launcher.xml type=XML
    resource 0x7f030001 mipmap/ic_launcher_round
      (mdpi-v4) (file) res/mipmap-mdpi-v4/ic_launcher_round.png type=PNG
      (hdpi-v4) (file) res/mipmap-hdpi-v4/ic_launcher_round.png type=PNG
      (xhdpi-v4) (file) res/mipmap-xhdpi-v4/ic_launcher_round.png type=PNG
      (xxhdpi-v4) (file) res/mipmap-xxhdpi-v4/ic_launcher_round.png type=PNG
      (xxxhdpi-v4) (file) res/mipmap-xxxhdpi-v4/ic_launcher_round.png type=PNG
      (anydpi-v26) (file) res/mipmap-anydpi-v26/ic_launcher_round.xml type=XML
  type string id=06 entryCount=4
    resource 0x7f060000 string/app_name
      () "Animal"
      (en-rXA) "[Åñîḿåļ one two]"
      (ar-rXB) "‏‮Animal‬‏"
    resource 0x7f060001 string/theme_default
      () "Default"
      (en-rXA) "[Ðéƒåûļţ one two]"
      (ar-rXB) "‏‮Default‬‏"
    resource 0x7f060002 string/theme_dog
      () "Dog"
      (en-rXA) "[Ðöĝ one]"
      (ar-rXB) "‏‮Dog‬‏"
    resource 0x7f060003 string/theme_monkey
      () "Monkey"
      (en-rXA) "[Ḿöñķéý one two]"
      (ar-rXB) "‏‮Monkey‬‏"
  type style id=07 entryCount=1
    resource 0x7f070000 style/AppTheme
      () (style) size=0 parent=0x01030060

参考：https://developer.android.com/studio/command-line/aapt2