android - Flutter - 如何减少设备上的应用程序大小

Question

我在 Google PlayStore 中的 App Bundle 下载大小约为 23 MB :



但是为什么安装后，磁盘上的应用程序大小显着增加到 83 MB :





知道为什么会发生这种情况，因为:

1) Flutter 的 Assets 文件(图像、声音和字体)仅在 左右的项目中使用11 MB

2) 仅磁盘上 Flutter 源代码 (.dart) 的大小 1.4 MB

3) Android Native Resource/icon (Res) only around 800 KB

关于我在下面使用的 flutter 插件:

dependencies:
  flutter:
    sdk: flutter
  flutter_localizations:
    sdk: flutter
  angles: ^1.0.1
  app_settings: ^1.0.5
  archive: ^2.0.8
  cached_network_image: ^1.1.1
  carousel_slider: ^1.3.0
  cron: ^0.2.1
  crypto: ^2.0.6
  cupertino_icons: ^0.1.2
  date_format: ^1.0.5
  device_id: ^0.1.3
  dio: ^2.0.0
  easy_alert: ^0.0.2
  localstorage: ^2.0.0
  audioplayers: ^0.13.1
  path_provider: ^1.1.0
  esys_flutter_share: ^1.0.2
  flutter_compass: ^0.3.2
  flutter_html: ^0.9.6
  flutter_local_notifications: ^0.8.2
  flutter_offline: ^0.2.4+1
  flutter_swiper: ^1.1.6
  flutter_xlider: ^2.4.5
  font_awesome_flutter: ^8.2.0
  geolocator: ^5.0.1
  google_maps_flutter: ^0.2.0
  google_sign_in: ^4.0.1+1
  http: ^0.12.0+2
  libcalendar: ^0.2.0
  location : ^2.3.0
  numberpicker: ^1.0.0
  pigment: ^1.0.3
  rxdart: ^0.21.0
  shared_preferences: ^0.5.1+1
  shimmer: ^1.0.0
  unicode: ^0.1.0
  url_launcher: ^5.0.2
  validate: ^1.6.0
  vibrate: ^0.0.4
  after_layout: ^1.0.7+2
  draggable_scrollbar: ^0.0.4
  flutter_web_browser: ^0.11.0
  flutter_youtube: ^1.1.6
  google_api_availability: ^2.0.1
  indexed_list_view: ^0.0.5
  permission_handler: ^3.1.0
  queries: ^0.1.4
  rect_getter: ^0.0.1
  scroll_to_index: any
  sqflite: ^1.1.5
  tuple: ^1.0.2
  xml2json: ^3.0.3
  firebase_messaging: ^5.1.6
  firebase_analytics: ^3.0.2
  firebase_core: ^0.4.0+3
  firebase_auth: ^0.11.1+6
  firebase_admob: ^0.9.0+1
  firebase_in_app_messaging: ^0.0.1+3
  superellipse_shape: ^0.1.5
  device_info: ^0.4.0+2
  in_app_purchase: ^0.2.0+6
  sentry: any
  system_info: ^0.1.1
  highlighter_coachmark: ^0.0.3
  volume: ^0.1.0
  admob_flutter: ^0.3.2
  bubble_tab_indicator: "^0.1.4"
  material_design_icons_flutter: ^3.0.3289
  scoped_model: ^1.0.1
  flutter_slidable: ^0.4.9
  kiwi: ^0.1.0
  flutter_markdown: ^0.2.0
  flutter_downloader: ^1.2.1
  native_ads: ^0.2.0  
  onesignal_flutter: ^2.0.0

任何想法如何减少 应用大小 ?

先感谢您...

更新

如果我设置 minifyEnabled = true和 shrinkResources = true (由 Ravinder Kumar 建议)在我的 build.gradle那么它会产生一个很长的错误，这是日志:

== Building for Android ==

... ( I cut the error log because of very long, but full log can bee seen here: https://www.dropbox.com/s/jy92d1lmj9pgb6d/full_flutter_error_log.txt?dl=0 )

Note: the configuration keeps the entry point 'io.flutter.plugins.googlesignin.GoogleSignInPlugin$Delegate$3 { void onComplete(com.google.android.gms.tasks.Task); }', but not the descriptor class 'com.google.android.gms.tasks.Task'

Note: the configuration keeps the entry point 'io.flutter.plugins.inapppurchase.Translator { java.util.HashMap fromSkuDetail(com.android.billingclient.api.SkuDetails); }', but not the descriptor class 'com.android.billingclient.api.SkuDetails'

Note: the configuration keeps the entry point 'io.flutter.plugins.inapppurchase.Translator { java.util.HashMap fromPurchase(com.android.billingclient.api.Purchase); }', but not the descriptor class 'com.android.billingclient.api.Purchase'

Note: the configuration keeps the entry point 'io.flutter.plugins.inapppurchase.Translator { java.util.HashMap fromPurchasesResult(com.android.billingclient.api.Purchase$PurchasesResult); }', but not the descriptor class 'com.android.billingclient.api.Purchase$PurchasesResult'

Note: there were 7 references to unknown classes.

     You should check your configuration for typos.

    (http://proguard.sourceforge.net/manual/troubleshooting.html#unknownclass)

Note: there were 3 references to unknown class members.

     You should check your configuration for typos.

Note: there were 242 unkept descriptor classes in kept class members.

     You should consider explicitly keeping the mentioned classes

     (using '-keep').

     (http://proguard.sourceforge.net/manual/troubleshooting.html#descriptorclass)

Note: there were 68 unresolved dynamic references to classes or interfaces.

     You should check if you need to specify additional program jars.

     (http://proguard.sourceforge.net/manual/troubleshooting.html#dynamicalclass)

Warning: there were 25 unresolved references to classes or interfaces.

        You may need to add missing library jars or update their versions.

        If your code works fine without the missing classes, you can suppress

        the warnings with '-dontwarn' options.

        (http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedclass)

Warning: there were 2 unresolved references to library class members.

        You probably need to update the library versions.

        (http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedlibraryclassmember)

Warning: Exception while processing task java.io.IOException: Please correct the above warnings first.

Thread(Tasks limiter_1): destruction Running Gradle task 'bundleRelease'... 690.7s (!)

************************************************************************>******************* The Gradle failure may have been because of AndroidX >incompatibilities in this Flutter app. See "https : //goo.gl / CP92wY" for more information on the problem and >how to fix it. ************************************************************************>******************* Gradle task bundleRelease failed with exit code 1

构建失败:|
无法为 Android 构建

顺便说一句，下面是我的 proguard-rules.pro :

#Flutter Wrapper
-keep class io.flutter.app.** { *; }
-keep class io.flutter.plugin.**  { *; }
-keep class io.flutter.util.**  { *; }
-keep class io.flutter.view.**  { *; }
-keep class io.flutter.**  { *; }
-keep class io.flutter.plugins.**  { *; }
-keep class com.baseflow.** { *; }
#-keep class com.chartboost.** { *; }

-dontwarn com.google.common.base.**
-keep class com.google.common.base.** {*;}
-dontwarn com.google.errorprone.annotations.**
-keep class com.google.errorprone.annotations.** {*;}
-dontwarn com.google.j2objc.annotations.**
-keep class com.google.j2objc.annotations.** { *; }
-dontwarn java.lang.ClassValue
-keep class java.lang.ClassValue { *; }
-dontwarn org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
-keep class org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement { *; }

Answer 1

我的回答是基于 Official document ,

• Remove unused resources
• Minimize resource imported from libraries
• Support a limited number of screen densities
• Compress PNG and JPEG files

除了这些，你还需要 启用 proguard 以减小 apk 的大小并防止应用逆向工程。 在 flutter 中，

To make your app as small as possible, you should enable shrinking in your release build to remove unused code and resources.

By default, Flutter does not obfuscate or minify the Android host. If you intend to use third-party Java, Kotlin, or Android libraries, you might want to reduce the size of the APK or protect that code from reverse engineering.

关注 this link在您的应用中启用 progaurd，

第 1 步:第 1 步 - 配置 Proguard
创建 /android/app/proguard-rules.pro文件并添加下面列出的规则。

## Flutter wrapper
-keep class io.flutter.app.** { *; }
-keep class io.flutter.plugin.**  { *; }
-keep class io.flutter.util.**  { *; }
-keep class io.flutter.view.**  { *; }
-keep class io.flutter.**  { *; }
-keep class io.flutter.plugins.**  { *; }
-dontwarn io.flutter.embedding.**

第 2 步:启用混淆和/或缩小

android {

    ...

    buildTypes {

        release {

            signingConfig signingConfigs.release

            minifyEnabled true
            shrinkResources true// to shrink your image resource read more at https://developer.android.com/studio/build/shrink-code
            useProguard true// enables progaurd

            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

        }
    }

注:仅在生产 apk 中使用 Proguard。

另外，阅读
Why does my app size on device differ than the APK or Play store size

An app depends on native libs too and most native libraries are android framework libraries that are available on the device also, so they won't get bundled in the apk/aab. But these libs will be included in the odex files and hence expands its size when installed.

问题:有什么可能的预防措施？

答: Minimize resource use from libraries

如果库是为服务器或桌面设计的，它可以包含许多应用程序不需要的对象和方法。要仅包含您的应用程序需要的库部分，如果许可证允许您修改库，您可以编辑库的文件。您还可以使用替代的、适合移动设备的库向您的应用程序添加特定功能。

Note: code shrinking can clean up some of a library's unnecessary code, but it might not be able to remove some large internal dependencies.

另请阅读此处提到的步骤

https://developer.android.com/topic/performance/reduce-apk-size#reduce-code