升级到 Android Studio 3.0 + Gradle 4.1 遇到的一些坑及解决方案 _android

五陵年少金市东，银鞍白马渡春风。这篇文章主要讲述升级到 Android Studio 3.0 + Gradle 4.1 遇到的一些坑及解决方案相关的知识，希望能为你提供帮助。
问题一:

Cannot set the value of read-only property ‘outputFile‘ for ApkVariantOutputImpl_Decorated{apkData=https://www.songbingjia.com/android/Main{type=MAIN, fullName=commonDebug, filters=[]}} of type com.android.build.gradle.internal.api.ApkVariantOutputImpl. Open File

解决方案一：https://stackoverflow.com/questions/44239235/android-gradle-3-0-0-alpha2-plugin-cannot-set-the-value-of-read-only-property
I used this code

applicationVariants.all { variant -> variant.outputs.each { output -> def outputFile = output.outputFile if (outputFile != null & & outputFile.name.endsWith(‘.apk‘)) { //输出apk名称为：应用名.apk def fileName = "xxx.apk" output.outputFile = new File(outputFile.parent, fileName) } } }

**Use all() instead of each()
Use outputFileName instead of output.outputFile if you change only file name (that is your case)**
Example from the guide:

// If you use each() to iterate through the variant objects, // you need to start using all(). That‘s because each() iterates // through only the objects that already exist during configuration time— // but those object don‘t exist at configuration time with the new model. // However, all() adapts to the new model by picking up object as they are // added during execution.android.applicationVariants.all { variant -> variant.outputs.all { outputFileName = "xxx.apk" } }

问题二:

Error:All flavors must now belong to a named flavor dimension. Learn more at https://d.android.com/r/tools/flavorDimensions-missing-error-message.html

解决方案二：http://blog.csdn.net/syif88/article/details/75009663
大致是说，Plugin 3.0.0之后有一种自动匹配消耗库的机制，便于debug variant 自动消耗一个库，然后就是必须要所有的flavor 都属于同一个维度。
为了避免flavor 不同产生误差的问题，应该在所有的库模块都使用同一个foo尺寸。
但是我们从中已经知道解决方案了：
在主 app 的 build.gradle 里面的

defaultConfig { targetSdkVersion：*** minSdkVersion ：*** versionCode：*** versionName ：***//版本名后面加句话，意思是flavor dimension 它的维度就是该版本号， //这样维度就是都是统一的了 **flavorDimensions "versionCode"**}

问题三：

Error:Execution failed for task ‘:youyoubao:javaPreCompileCommonDebug‘. > Annotation processors must be explicitly declared now.The following dependencies on the compile classpath are found to contain annotation processor.Please add them to the annotationProcessor configuration. - butterknife-compiler-8.6.0.jar (com.jakewharton:butterknife-compiler:8.6.0) Alternatively, set android.defaultConfig.javaCompileOptions.annotationProcessorOptions.includeCompileClasspath = true to continue with previous behavior.Note that this option is deprecated and will be removed in the future. See https://developer.android.com/r/tools/annotation-processor-error-message.html for more details.

解决方案三：【升级到 Android Studio 3.0 + Gradle 4.1 遇到的一些坑及解决方案】在 app 下的 build.gradle 的 defaultConfig 中加一句话：

defaultConfig { ... javaCompileOptions { annotationProcessorOptions { includeCompileClasspath = true } } } 转： https://blog.csdn.net/CHITTY1993/article/details/78667069

Cannot set the value of read-only property ‘outputFile‘ for ApkVariantOutputImpl_Decorated 今天升级了AS3.0以后，在项目编译的时候发现Gradle中报错了，错误如下： Error:(60, 0) Cannot set the value of read-only property ‘outputFile‘ for ApkVariantOutputImpl_Decorated{apkData=https://www.songbingjia.com/android/Main{type=MAIN, fullName=xiaomiRelease, filters=[]}} of type com.android.build.gradle.internal.api.ApkVariantOutputImpl. < a href="openFile:E:StudioMyApplicationCodeBookuild.gradle"> Open File< /a> 经过一番折腾，网上找大牛的解读，弄明白了output.outputFile变成了只读属性，不能再往里面写东西了，以下是3.0之前的配置：

applicationVariants.all { variant -> //批量修改Apk名字 variant.outputs.each { output -> def outputFile = output.outputFile if (outputFile != null & & outputFile.name.endsWith(‘.apk‘) & & ‘release‘.equals(variant.buildType.name)) { def fileName = outputFile.name.replace("${variant.flavorName}", "V${defaultConfig.versionName}-${variant.flavorName}") fileName = fileName.replace(‘.apk‘, "-${buildTime()}.apk") output.outputFile = new File(outputFile.parent, fileName) } } }

下面是经过修改之后3.0里面批量修改APK名字的配置：

applicationVariants.all { variant -> //批量修改Apk名字 variant.outputs.all { output -> if (!variant.buildType.isDebuggable()) { //获取签名的名字 variant.signingConfig.name //要被替换的源字符串 def sourceFile = "-${variant.flavorName}-${variant.buildType.name}" //替换的字符串 def replaceFile = "_V${variant.versionName}_${variant.flavorName}_${variant.buildType.name}_${buildTime()}" outputFileName = output.outputFile.name.replace(sourceFile, replaceFile); //遗留问题：如何获取当前module的name，如CodeBooke这个名字怎么获取到 } } }

问题：对于如何在gradle中获取module的name，还是没有找到相关的方法，希望有知道的大神留言交流。 gradle API：https://developer.android.google.cn/studio/build/gradle-plugin-3-0-0-migration.html#variant_api 这是一个对AS 3.0变化总结比较全的博客： https://mp.weixin.qq.com/s?__biz=MzAwNzc0NjAxMg==& mid=2653391711& idx=1& sn=821eff3f98ab52fc442c6218794b203e& chksm=80aa53ecb7dddafa522d4ebfdf67af2f473365bb0fa2d50ae6df5d00499926ae0d32a5a448d2& mpshare=1& scene=23& srcid=10308c4ICo7GCwuVc683H6eZ#rd