前言

前面介绍了Flutter中一些基本Widget的使用方法,下面我们来先下实战中是如何构建生成Android包的,本文我们主要介绍纯Flutter项目生成Android包的方法,以及遇到的问题

正文

  • 1、生成签名文件
    这个步骤对于一个Android开发来说应该是很简单的,这里我就不进行赘述,需要的小伙伴可以参考Android的签名文件生成两种方法
  • 2、配置gradle文件
    在/android/目录下创建一个key.properties的文件,包含我们所需要一些内容,例如
storePassword="你签名设置的密码"
keyPassword="你签名设置的密码"
keyAlias="你签名的别名"
storeFile="你的签名文件存放的路径"

在android/app/build.gradle文件中添加下面的信息

def keystorePropertiesFile = rootProject.file("key.properties")
def keystoreProperties = new Properties()
if (keystorePropertiesFile.exists()){
    keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
}
android{
  ...
signingConfigs {   
        release {
            keyAlias keystoreProperties['keyAlias']
            keyPassword keystoreProperties['keyPassword']
            storeFile file(keystoreProperties['storeFile'])
            storePassword keystoreProperties['storePassword']
        }
    }
buildTypes {
        release {
            signingConfig signingConfigs.release
        }
    }
}
  • 3、配置混淆
    在/android/app/目录下创建proguard-rules.pro文件,并添加内容
#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.**  { *; }

PS:之后需要混淆的库都添加在这个文件中

然后在android/app/build.gradle文件中添加下面的信息

android {
    ...
    buildTypes {
        release {
            signingConfig signingConfigs.release  //使用正式release配置
            minifyEnabled true //是否压缩
            useProguard true //打开混淆
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' //配置混淆文件
        }
    }
}

此时关于打包的前期配置就结束了,下面开始执行命令进行打包

  • cd到工程目录下
  • flutter build apk
    顺利的话我们会看到如下内容
tianchibindeMacBook-Pro:flutter_build_apk tiancb$ flutter build apk
You are building a fat APK that includes binaries for android-arm, android-arm64, android-x64.
If you are deploying the app to the Play Store, it's recommended to use app bundles or split the APK to reduce the APK size.
    To generate an app bundle, run:
        flutter build appbundle --target-platform android-arm,android-arm64,android-x64
        Learn more on: https://developer.android.com/guide/app-bundle
    To split the APKs per ABI, run:
        flutter build apk --target-platform android-arm,android-arm64,android-x64 --split-per-abi
        Learn more on:  https://developer.android.com/studio/build/configure-apk-splits#configure-abi-split
[!] Your app isn't using AndroidX.
    To avoid potential build failures, you can quickly migrate your app by following the steps on https://goo.gl/CP92wY.
Removed unused resources: Binary resource data reduced from 44KB to 35KB: Removed 20%
Running Gradle task 'assembleRelease'...                                
Running Gradle task 'assembleRelease'... Done                      47.0s
✓ Built build/app/outputs/apk/release/app-release.apk (15.3MB).

最后的build/app/outputs/apk/release/app-release.apk这是apk包的路径。
上面我们说到,顺利的话会直接生成apk包,现在我们来看下打包的过程中遇到的问题

Q1:ProcessException: Bad CPU type in executable
完整的日志是

ProcessException: Bad CPU type in executable                            
  Command: /Users/tiancb/Desktop/Android/flutter/bin/cache/artifacts/engine/android-arm-release/darwin-x64/gen_snapshot --causal_async_stacks --deterministic --snapshot_kind=app-aot-elf --elf=/Users/tiancb/Desktop/Flutter/flutter_build_apk/build/app/intermediates/flutter/release/android-arm/app.so --strip --no-sim-use-hardfp --no-use-integer-division /Users/tiancb/Desktop/Flutter/flutter_build_apk/build/app/intermediates/flutter/release/android-arm/app.dill
#0      runCommandAndStreamOutput (package:flutter_tools/src/base/process.dart:142:27)
                                               
#1      GenSnapshot.run (package:flutter_tools/src/base/build.dart:75:12)
#2      AOTSnapshotter.build. (package:flutter_tools/src/base/build.dart:211:27)
#3      AOTSnapshotter._timedStep (package:flutter_tools/src/base/build.dart:344:33)
                                               
#4      AOTSnapshotter.build (package:flutter_tools/src/base/build.dart:210:13)
                                               
#5      BuildAotCommand.runCommand (package:flutter_tools/src/commands/build_aot.dart:149:56)
                                               
#6      FlutterCommand.verifyThenRunCommand (package:flutter_tools/src/runner/flutter_command.dart:478:18)
                                               
#7      FlutterCommand.run. (package:flutter_tools/src/runner/flutter_command.dart:383:33)
                                               
#8      AppContext.run. (package:flutter_tools/src/base/context.dart:153:29)
                                               
#9      _rootRun (dart:async/zone.dart:1124:13)                         
#10     _CustomZone.run (dart:async/zone.dart:1021:19)                  
#11     _runZoned (dart:async/zone.dart:1516:10)                        
#12     runZoned (dart:async/zone.dart:1463:12)                         
#13     AppContext.run (package:flutter_tools/src/base/context.dart:152:18)
                                               
#14     FlutterCommand.run (package:flutter_tools/src/runner/flutter_command.dart:375:20)
#15     CommandRunner.runCommand (package:args/command_runner.dart:197:27)
                                               
#16     FlutterCommandRunner.runCommand. (package:flutter_tools/src/runner/flutter_command_runner.dart:396:21)
                                               
#17     AppContext.run. (package:flutter_tools/src/base/context.dart:153:29)
                                               
#18     _rootRun (dart:async/zone.dart:1124:13)                         
#19     _CustomZone.run (dart:async/zone.dart:1021:19)                  
#20     _runZoned (dart:async/zone.dart:1516:10)                        
#21     runZoned (dart:async/zone.dart:1463:12)                         
#22     AppContext.run (package:flutter_tools/src/base/context.dart:152:18)
                                               
#23     FlutterCommandRunner.runCommand (package:flutter_tools/src/runner/flutter_command_runner.dart:356:19)
                                               
#24     CommandRunner.run. (package:args/command_runner.dart:112:25)
#25     new Future.sync (dart:async/future.dart:224:31)                 
#26     CommandRunner.run (package:args/command_runner.dart:112:14)     
#27     FlutterCommandRunner.run (package:flutter_tools/src/runner/flutter_command_runner.dart:242:18)
#28     run.. (package:flutter_tools/runner.dart:62:22)
                                               
#29     _rootRun (dart:async/zone.dart:1124:13)                         
#30     _CustomZone.run (dart:async/zone.dart:1021:19)                  
#31     _runZoned (dart:async/zone.dart:1516:10)                        
#32     runZoned (dart:async/zone.dart:1500:12)                         
#33     run. (package:flutter_tools/runner.dart:60:18)
                                               
#34     AppContext.run. (package:flutter_tools/src/base/context.dart:153:29)
                                               
#35     _rootRun (dart:async/zone.dart:1124:13)                         
#36     _CustomZone.run (dart:async/zone.dart:1021:19)                  
#37     _runZoned (dart:async/zone.dart:1516:10)                        
#38     runZoned (dart:async/zone.dart:1463:12)                         
#39     AppContext.run (package:flutter_tools/src/base/context.dart:152:18)
                                               
#40     runInContext (package:flutter_tools/src/context_runner.dart:56:24)
                                               
#41     run (package:flutter_tools/runner.dart:51:10)                   
#42     main (package:flutter_tools/executable.dart:62:9)               
                                               
#43     main (file:///Users/tiancb/Desktop/Android/flutter/packages/flutter_tools/bin/flutter_tools.dart:8:3)
#44     _startIsolate. (dart:isolate-patch/isolate_patch.dart:299:32)
#45     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:172:12)
                                                                        
                                                                        
FAILURE: Build failed with an exception.                                
                                                                        
* Where:                                                                
Script '/Users/tiancb/Desktop/Android/flutter/packages/flutter_tools/gradle/flutter.gradle' line: 638
                                                                        
* What went wrong:                                                      
Execution failed for task ':app:compileflutterBuildReleaseArm'.         
> Process 'command '/Users/tiancb/Desktop/Android/flutter/bin/flutter'' finished with non-zero exit value 1
                                                                        
* Try:                                                                  
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

解决方法-执行下面的

flutter doctor –android-licenses

执行完之后会有一个

Accept? (y/N): 

直接选择y就行了

Q2 – Could not download …
完整的错误日志是

Could not resolve all files for configuration ':app:releaseCompileClasspath'.                                      
> Could not download armeabi_v7a_release.jar (io.flutter:armeabi_v7a_release:1.0.0-af04338413c3ed73316350f64248a152433073b6)
   > Could not get resource 'http://download.flutter.io/io/flutter/armeabi_v7a_release/1.0.0-af04338413c3ed73316350f64248a152433073b6/armeabi_v7a_release-1.0.0-af04338413c3ed73316350f64248a152433073b6.jar'.
      > Could not HEAD 'http://download.flutter.io/io/flutter/armeabi_v7a_release/1.0.0-af04338413c3ed73316350f64248a152433073b6/armeabi_v7a_release-1.0.0-af04338413c3ed73316350f64248a152433073b6.jar'.
         > Connect to download.flutter.io:80 [download.flutter.io/172.217.160.80, download.flutter.io/2404:6800:4012:0:0:0:0:2010] failed: No route to host (connect failed)
                                                                                                                   
* Try:                                                                                                             
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* What went wrong:                                                                                                 
Execution failed for task ':app:lintVitalRelease'.                                                                 
> Could not resolve all artifacts for configuration ':app:profileRuntimeClasspath'.                                
   > Could not download arm64_v8a_profile.jar (io.flutter:arm64_v8a_profile:1.0.0-af04338413c3ed73316350f64248a152433073b6)
      > Could not get resource 'http://download.flutter.io/io/flutter/arm64_v8a_profile/1.0.0-af04338413c3ed73316350f64248a152433073b6/arm64_v8a_profile-1.0.0-af04338413c3ed73316350f64248a152433073b6.jar'.
         > Could not GET 'http://download.flutter.io/io/flutter/arm64_v8a_profile/1.0.0-af04338413c3ed73316350f64248a152433073b6/arm64_v8a_profile-1.0.0-af04338413c3ed73316350f64248a152433073b6.jar'.
            > Read timed out                                                                                       
                                                                                                                   
* Try:                                                                                                             
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
        

解决方案

翻墙 – 你懂的

结语

截止到这里,纯Flutter项目的打包过程就讲述完了。

以下是我的Flutter系列的链接,后续会持续更新,欢迎大家指正。

Flutter 系列文章

  • Flutter 学习 – 开篇
  • Flutter 学习 – 基础框架
  • Flutter 学习 – 网络请求和数据解析
  • Flutter 学习 – Widget 之 Text
  • Flutter 学习 – Widget 之 RichText
  • Flutter 学习 – Widget 之 Image和Icon
  • Flutter 学习 – Widget 之 TextField
  • Flutter 学习 – Widget 之 菜单按钮
  • Flutter 学习 – Widget 之 布局 Widget
  • Flutter 学习 – 容器类Widget
  • Flutter 学习 – 可滚动的 Widget
  • Flutter 学习 – 功能类Widget

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Flutter 学习之打包 – 纯Flutter项目生成Android包