Android之aapt

Android之aapt
在Android.mk中有LOCAL_AAPT_FLAGS配置项，在gradle中也有aaptOptions，那么aapt到底是干什么的呢？
aapt即Android Asset Packaging Tool，在SDK的build-tools目录下。该工具可以查看，创建， 更新ZIP格式的文档附件(zip, jar, apk)。也可将资源文件编译成二进制文件，尽管你可能没有直接使用过aapt工具，但是build scripts和IDE插件会使用这个工具打包apk文件构成一个Android 应用程序。也就是上面我们说的两项配置。

aapt参数

先看看aapt help：

Usage:
 aapt l[ist] [-v] [-a] file.{zip,jar,apk}
   List contents of Zip-compatible archive.

 aapt d[ump] [--values] [--include-meta-data] WHAT file.{apk} [asset [asset ...]]
   strings          Print the contents of the resource table string pool in the APK.
   badging          Print the label and icon for the app declared in APK.
   permissions      Print the permissions from the APK.
   resources        Print the resource table from the APK.
   configurations   Print the configurations in the APK.
   xmltree          Print the compiled xmls in the given assets.
   xmlstrings       Print the strings of the given compiled xml assets.

 aapt p[ackage] [-d][-f][-m][-u][-v][-x][-z][-M AndroidManifest.xml] \
        [-0 extension [-0 extension ...]] [-g tolerance] [-j jarfile] \
        [--debug-mode] [--min-sdk-version VAL] [--target-sdk-version VAL] \
        [--app-version VAL] [--app-version-name TEXT] [--custom-package VAL] \
        [--rename-manifest-package PACKAGE] \
        [--rename-instrumentation-target-package PACKAGE] \
        [--utf16] [--auto-add-overlay] \
        [--max-res-version VAL] \
        [-I base-package [-I base-package ...]] \
        [-A asset-source-dir]  [-G class-list-file] [-P public-definitions-file] \
        [-S resource-sources [-S resource-sources ...]] \
        [-F apk-file] [-J R-file-dir] \
        [--product product1,product2,...] \
        [-c CONFIGS] [--preferred-density DENSITY] \
        [--split CONFIGS [--split CONFIGS]] \
        [--feature-of package [--feature-after package]] \
        [raw-files-dir [raw-files-dir] ...] \
        [--output-text-symbols DIR]

   Package the android resources.  It will read assets and resources that are
   supplied with the -M -A -S or raw-files-dir arguments.  The -J -P -F and -R
   options control which files are output.

 aapt r[emove] [-v] file.{zip,jar,apk} file1 [file2 ...]
   Delete specified files from Zip-compatible archive.

 aapt a[dd] [-v] file.{zip,jar,apk} file1 [file2 ...]
   Add specified files to Zip-compatible archive.

 aapt c[runch] [-v] -S resource-sources ... -C output-folder ...
   Do PNG preprocessing on one or several resource folders
   and store the results in the output folder.

 aapt s[ingleCrunch] [-v] -i input-file -o outputfile
   Do PNG preprocessing on a single file.

 aapt v[ersion]
   Print program version.

 Modifiers:
   -a  print Android-specific data (resources, manifest) when listing
   -c  specify which configurations to include.  The default is all
       configurations.  The value of the parameter should be a comma
       separated list of configuration values.  Locales should be specified
       as either a language or language-region pair.  Some examples:
            en
            port,en
            port,land,en_US
   -d  one or more device assets to include, separated by commas
   -f  force overwrite of existing files
   -g  specify a pixel tolerance to force images to grayscale, default 0
   -j  specify a jar or zip file containing classes to include
   -k  junk path of file(s) added
   -m  make package directories under location specified by -J
   -u  update existing packages (add new, replace older, remove deleted files)
   -v  verbose output
   -x  create extending (non-application) resource IDs
   -z  require localization of resource attributes marked with
       localization="suggested"
   -A  additional directory in which to find raw asset files
   -G  A file to output proguard options into.
   -F  specify the apk file to output
   -I  add an existing package to base include set
   -J  specify where to output R.java resource constant definitions
   -M  specify full path to AndroidManifest.xml to include in zip
   -P  specify where to output public resource definitions
   -S  directory in which to find resources.  Multiple directories will be scanned
       and the first match found (left to right) will take precedence.
   -0  specifies an additional extension for which such files will not
       be stored compressed in the .apk.  An empty string means to not
       compress any files at all.
   --debug-mode
       inserts android:debuggable="true" in to the application node of the
       manifest, making the application debuggable even on production devices.
   --include-meta-data
       when used with "dump badging" also includes meta-data tags.
   --pseudo-localize
       generate resources for pseudo-locales (en-XA and ar-XB).
   --min-sdk-version
       inserts android:minSdkVersion in to manifest.  If the version is 7 or
       higher, the default encoding for resources will be in UTF-8.
   --target-sdk-version
       inserts android:targetSdkVersion in to manifest.
   --max-res-version
       ignores versioned resource directories above the given value.
   --values
       when used with "dump resources" also includes resource values.
   --version-code
       inserts android:versionCode in to manifest.
   --version-name
       inserts android:versionName in to manifest.
   --replace-version
       If --version-code and/or --version-name are specified, these
       values will replace any value already in the manifest. By
       default, nothing is changed if the manifest already defines
       these attributes.
   --custom-package
       generates R.java into a different package.
   --extra-packages
       generate R.java for libraries. Separate libraries with ':'.
   --generate-dependencies
       generate dependency files in the same directories for R.java and resource package
   --auto-add-overlay
       Automatically add resources that are only in overlays.
   --preferred-density
       Specifies a preference for a particular density. Resources that do not
       match this density and have variants that are a closer match are removed.
   --split
       Builds a separate split APK for the configurations listed. This can
       be loaded alongside the base APK at runtime.
   --feature-of
       Builds a split APK that is a feature of the apk specified here. Resources
       in the base APK can be referenced from the the feature APK.
   --feature-after
       An app can have multiple Feature Split APKs which must be totally ordered.
       If --feature-of is specified, this flag specifies which Feature Split APK
       comes before this one. The first Feature Split APK should not define
       anything here.
   --rename-manifest-package
       Rewrite the manifest so that its package name is the package name
       given here.  Relative class names (for example .Foo) will be
       changed to absolute names with the old package so that the code
       does not need to change.
   --rename-instrumentation-target-package
       Rewrite the manifest so that all of its instrumentation
       components target the given package.  Useful when used in
       conjunction with --rename-manifest-package to fix tests against
       a package that has been renamed.
   --product
       Specifies which variant to choose for strings that have
       product variants
   --utf16
       changes default encoding for resources to UTF-16.  Only useful when API
       level is set to 7 or higher where the default encoding is UTF-8.
   --non-constant-id
       Make the resources ID non constant. This is required to make an R java class
       that does not contain the final value but is used to make reusable compiled
       libraries that need to access resources.
   --shared-lib
       Make a shared library resource package that can be loaded by an application
       at runtime to access the libraries resources. Implies --non-constant-id.
   --error-on-failed-insert
       Forces aapt to return an error if it fails to insert values into the manifest
       with --debug-mode, --min-sdk-version, --target-sdk-version --version-code
       and --version-name.
       Insertion typically fails if the manifest already defines the attribute.
   --error-on-missing-config-entry
       Forces aapt to return an error if it fails to find an entry for a configuration.
   --output-text-symbols
       Generates a text file containing the resource symbols of the R class in the
       specified folder.
   --ignore-assets
       Assets to be ignored. Default pattern is:
       !.svn:!.git:!.ds_store:!*.scc:.*:_*:!CVS:!thumbs.db:!picasa.ini:!*~
   --skip-symbols-without-default-localization
       Prevents symbols from being generated for strings that do not have a default
       localization
   --no-version-vectors
       Do not automatically generate versioned copies of vector XML resources.

–extra-packages

这个参数在
http://blog.csdn.net/heqiangflytosky/article/details/12039125
和
http://blog.csdn.net/heqiangflytosky/article/details/50853268
已经介绍过了：
Gradle

//--extra-packages是为资源文件设置别名：意思是通过该应用包名+R，com.android.test1.R和com.android.test2.R都可以访问到资源
additionalParameters '--extra-packages', 'com.android.test1','--extra-packages','com.android.test2'

Android.mk

LOCAL_AAPT_FLAGS += --extra-packages org.chromium.content
LOCAL_AAPT_FLAGS += --extra-packages org.chromium.ui

R资源生成别名：如果是com.android.test.R，会同时生成org.chromium.content.R和org.chromium.ui.R

-S

http://blog.zhaiyifan.cn/2016/02/18/android-resource-overlay/
overlay通过-S指定，可以指定多个目录
Gradle
随便建两个res文件夹，各放两个strings.xml，res2和res3分别定义了一个string “hehe”，value分别为”hehe res2”和”hehe res3”。
content_main.xml的TextView使用了hehe（原来就是那个Hello World）。当然这里as会报错，因为res2和res3并没有标示为资源文件夹。
在module的build.gradle里:

  aaptOptions {
      additionalParameters '-S',
              '/Users/yifan/dev/github/Testapp/app/src/main/res3',
              '-S',
              '/Users/yifan/dev/github/Testapp/app/src/main/res2',
              '--auto-add-overlay'
      noCompress 'foo', 'bar'
      ignoreAssetsPattern '!.svn:!.git:!.ds_store:!*.scc:.*:_*:!CVS:!thumbs.db:!picasa.ini:!*~'
  }

成功编译运行。
最后使用的是hehe res3，交换-S顺序后则变成了hehe res2，符合我们第一节中说到的，选择首个匹配原则。
不仅是string，anim，layout等等资源都可以使用重叠包来进行动态指定。

–auto-add-overlay

http://blog.zhaiyifan.cn/2016/02/18/android-resource-overlay/
自动添加overlays包里的资源

资源合并

http://blog.zhaiyifan.cn/2016/02/18/android-resource-overlay/
http://tools.android.com/tech-docs/new-build-system/resource-merging

待续……