multiDex分包时指定主dex的class列表

afterEvaluate {
    tasks.matching {
        it.name.startsWith('dex')
    }.each { dx ->
       def listMain = project.rootDir.absolutePath+'/app/maindexlist.txt'
        if (dx.additionalParameters == null) {
            dx.additionalParameters = []
        }
       //改变dex方法数上线为50000，超过后进行拆分
       dx.additionalParameters += '--set-max-idx-number=50000'
        //方法数越界时则生成多个dex文件
        dx.additionalParameters += '--multi-dex'
        //maindexlist.txt文件为主dex中的类型配置文件
        dx.additionalParameters += '--main-dex-list=' + listMain
        //-main-dex-list指定的所有class会打包到主dex中
       dx.additionalParameters += '--minimal-main-dex'
　　
    }
}

  dexOptions {
        javaMaxHeapSize "4g"
        preDexLibraries = false
        additionalParameters = ['--multi-dex', '--main-dex-list=' + project.rootDir.absolutePath + '/app/maindexlist.txt', '--minimal-main-dex',
                                '--set-max-idx-number=1000']
    }