flutter编译报错（minSdkVersion、Kotlin、dex文件、Java11）_flutter.minsdkversion

1.minSdkVersion版本提升

minSdkVersion版本问题：

FAILURE: Build failed with an exception.

  * What went wrong:
  Execution failed for task ':app:processDebugManifest'.
  > Manifest merger failed : uses-sdk:minSdkVersion 16 cannot be smaller than version 19 declared in library [:flutter_blue] /home/maldus/Projects/flutter/polmac/build/flutter_blue/intermediates/manifests/full/debug/AndroidManifest.xml as the library might be using APIs not available in 16
    Suggestion: use a compatible library with a minSdk of at most 16,
            or increase this project's minSdk version to at least 19,
            or use tools:overrideLibrary="com.pauldemarco.flutterblue" to force usage (may lead to runtime failures)
1
2
3
4
5
6
7
8

换言之，主要原因在minSdkVersion版本上，至少是19。AndroidManifest.xml中的版本是19，E:\work\filename\projectname\android\app\build.gradle的defaultConfig 下的minSdkVersion flutter.minSdkVersion（D:\flutter\flutter\packages\flutter_tools\gradle）配置路径下版本是16。

class FlutterExtension {
/** Sets the compileSdkVersion used by default in Flutter app projects. */
static int compileSdkVersion = 33

/** Sets the minSdkVersion used by default in Flutter app projects. */
static int minSdkVersion = 16

/** Sets the targetSdkVersion used by default in Flutter app projects. */
static int targetSdkVersion = 33
}
1
2
3
4
5
6
7
8
9
10

“百度”老师建议要把版本在此路径下更改为>=19。将其改为 static int minSdkVersion = 20，此问题解决。
注意： 不要直接改为此字样“>=19”，无法识别会再次报错！

2.缓存路径报错Kotlin版本问题

接着重新编译，有报了一个有关缓存的bug。

e: C:/Users/username/.gradle/caches/modules-2/files-2.1/androidx.lifecycle/lifecycle-common/2.6.1/10f354fdb64868baecd67128560c5a0d6312c495/lifecycle-common-2.6.1.jar!/META-INF/lifecycle-common.kotlin module: Module was compiled with an incompatible version of Kotlin. The binary version of its metadata is 1.8.0, expected version is 1.6.0.
1

遇事不决先问“百度”老师，听从建议先清空缓存，把报了错的路径的文件删除重新编译。经过多次尝试，还是会报这个错。既然是版本问题，何不找到对应版本启动配置的路径做更改呢。
于是，在E:\work\filename\projectname\android\build.gradle下，将buildscript 下的 ext.kotlin_version = '1.6.10' 版本改为 ext.kotlin_version = '1.8.0' 。

3.dex文件中的方法引用数量不能超过64K

出现新的bug:

ERROR:D8: Cannot fit requested classes in a single dex file (# methods: 67171 > 65536) com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: The number of method references in a .dex file cannot exceed 64K.
1

“百度”：在Android 5.0之前的版本（API level < 21）中使用Dalvik runtime执行代码，默认限制每个APK只能使用一个classes.dex文件，而DEX规范又将单个DEX文件内引用的方法总数限制为65536个，第三方引入过多所以导致函数超限。
解决方案：
在E:\work\filename\projectname\android\app\build.gradle下,新增：

android {
  defaultConfig{
      multiDexEnabled true
  }
}
dependencies {  
   implementation 'com.android.support:multidex:1.0.3'
}
1
2
3
4
5
6
7
8

4.Android Gradle插件需要Java 11

评估项目’:app’时出现问题。应用插件’com.android.internal.application’失败。> Android Gradle插件需要Java 11才能运行。您当前使用的是Java 1.8。

 problem occurred evaluating project ':app'.
> Failed to apply plugin 'com.android.internal.application'.
   > Android Gradle plugin requires Java 11 to run. You are currently using Java 1.8.
1
2
3

检查自己本机环境下的的Java版本确实是11，可能它访问的路径默认是默认的之前安装的Java1.8路径。之后在相应的文件E:\work\filename\projectname\android\app\build.gradle下手动增加访问的Java版本的路径。org.gradle.java.home=C:/Program Files/Microsoft/jdk-11.0.16.101-hotspot。
全部内容：
org.gradle.jvmargs=-Xmx8192M android.useAndroidX=true android.enableJetifier=true org.gradle.java.home=C:/Program Files/Microsoft/jdk-11.0.16.101-hotspot

再次运行。

编译成功。