升級到 Android Studio 3.0 + Gradle 4.1 遇到的一些坑及解決方案

問題一:

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

解決方案一：

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')) { //輸出apk名稱為：應用名.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" } }

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問題二:

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

解決方案二：

http://blog.csdn.net/syif88/article/details/75009663

大致是說，Plugin 3.0.0之后有一種自動匹配消耗庫的機制，便於debug variant 自動消耗一個庫，然后就是必須要所有的flavor 都屬於同一個維度。 
為了避免flavor 不同產生誤差的問題，應該在所有的庫模塊都使用同一個foo尺寸。

但是我們從中已經知道解決方案了：

在主 app 的 build.gradle 里面的

defaultConfig {
 targetSdkVersion：*** minSdkVersion ：*** versionCode：*** versionName ：*** //版本名后面加句話，意思是flavor dimension 它的維度就是該版本號， //這樣維度就是都是統一的了 **flavorDimensions "versionCode"** }

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問題三：

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.

解決方案三：

在 app 下的 build.gradle 的 defaultConfig 中加一句話：

defaultConfig {
   ... javaCompileOptions { annotationProcessorOptions { includeCompileClasspath = true } } }


轉：
https://blog.csdn.net/CHITTY1993/article/details/78667069

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Cannot set the value of read-only property 'outputFile' for ApkVariantOutputImpl_Decorated

今天升級了AS3.0以后，在項目編譯的時候發現Gradle中報錯了，錯誤如下：

Error:(60, 0) Cannot set the value of read-only property 'outputFile' for ApkVariantOutputImpl_Decorated{apkData=Main{type=MAIN, fullName=xiaomiRelease, filters=[]}} of type com.android.build.gradle.internal.api.ApkVariantOutputImpl.

<a href="openFile:E:\Studio\MyApplication\CodeBook\build.gradle">Open File</a>

經過一番折騰，網上找大牛的解讀，弄明白了output.outputFile變成了只讀屬性，不能再往里面寫東西了，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)

        }

    }

}

下面是經過修改之后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()) {

            //獲取簽名的名字 variant.signingConfig.name

            //要被替換的源字符串

            def sourceFile = "-${variant.flavorName}-${variant.buildType.name}"

            //替換的字符串

            def replaceFile = "_V${variant.versionName}_${variant.flavorName}_${variant.buildType.name}_${buildTime()}"

            outputFileName = output.outputFile.name.replace(sourceFile, replaceFile);

            //遺留問題：如何獲取當前module的name，如CodeBooke這個名字怎么獲取到

        }

    }

}

問題：對於如何在gradle中獲取module的name，還是沒有找到相關的方法，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

這是一個對AS 3.0變化總結比較全的博客：

https://mp.weixin.qq.com/s?__biz=MzAwNzc0NjAxMg==&mid=2653391711&idx=1&sn=821eff3f98ab52fc442c6218794b203e&chksm=80aa53ecb7dddafa522d4ebfdf67af2f473365bb0fa2d50ae6df5d00499926ae0d32a5a448d2&mpshare=1&scene=23&srcid=10308c4ICo7GCwuVc683H6eZ#rd