Android aapt自動打包工具
概念
在Android.mk中有LOCAL_AAPT_FLAGS配置項，在gradle中也有aaptOptions，那么aapt到底是干什么的呢？ aapt即Android Asset Packaging Tool（Android 打包工具），在SDK的build-tools目錄下。我們可以查 看，創建， 更新ZIP格式的文檔附件(zip, jar, apk)。也可將資源文件編譯成二進制文件，盡管你可能沒有直接使用過aapt工具，但是build scripts和IDE插件會使用這個工具打包apk文件構成一個Android 應用程序。
aapt打包流程
aapt傳統的打包主要是最res和Java代碼的打包，aapt打包走的是單線程、流水式的任務從上到下進行打包構建。
傳統的aapt打包，aapt會執行2次，第一次是生成R.java，參與javac編譯，第二次是對res里面的資源文件進行編譯，最后APKBuilder會把DEX文件與編譯好的資源文件及DEX文件進行打包成APK，簽名并安裝至手機。整個流程下來，沒有任何緩存，沒有并發，也沒有增量，每次構建都是一個全新的過程，所以每次構建時間也比較恒定，代碼量，資源量越多，構建時間越慢。
aapt常用的參數
我們可以通過aapt help來查看常用的參數。
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:.*:<dir>_*:!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.關于上面參數的具體含義大家可以自行去了解，但是有幾個常用的參數是需要記住的。
aapt常用命令
1. 列出apk包的內容
aapt l[ist] [-v] [-a] file.{zip,jar,apk}
-v 以table形式列出來
-a 詳細列出內容
例如：aapt l <你的apk文件>，這個命令就是查看apk內容
#### 2. 查看apk一些信息