Android Gradle3.0以后多渠道打包报错问题解决

从gradle2.x升级到4.x之后，会收到这样一个警告。虽然不影响使用，但是看起来确实挺糟心的。

WARNING: API 'variantOutput.getPackageApplication()' is obsolete and has been replaced with 'variant.getPackageApplicationProvider()'.
It will be removed at the end of 2019.
For more information, see https://d.android.com/r/tools/task-configuration-avoidance.
To determine what is calling variantOutput.getPackageApplication(), use -Pandroid.debug.obsoleteApi=true on the command line to display a stack trace.
Affected Modules: app

之前是这样的

android.applicationVariants.all { variant ->
    if (variant.buildType.name == "sit") {
        variant.outputs.each { output ->
            if (output.outputFile != null && output.outputFile.name.endsWith('.apk')) {
                def task = project.tasks.create("copyAndRename${variant.name}Apk", Copy)
                def fileName = output.outputFile.name
                fileName = fileName.replace("-sit", "")
                output.outputFile = new File(output.outputFile.parent + '/sit/', fileName)
                task.doFirst {
                    println "Copying ${fileName}" + " to apk directory..."
                }
                task.doLast {
                    println "Done with sit"
                }
                task.from(output.outputFile)
                task.into("deploy-sit")

                task.dependsOn "assemble${variant.name.capitalize()}"
                doSitTask.dependsOn task
            }
        }
    }
}

改造之后是这样的

android.applicationVariants.all { variant ->
    if (variant.buildType.name == "sit") {
        variant.outputs.all {
            outputFileName = outputFileName.replace("-sit", "")
            def task = project.tasks.create("copyAndRename${variant.name}Apk", Copy)
            task.doFirst {
                println "Copying ${outputFileName}" + " to apk directory..."
            }
            task.doLast {
                println "Done with sit"
            }
            task.from(variant.getPackageApplicationProvider().get().outputDirectory)
            task.into("deploy-sit")

            task.dependsOn "assemble${variant.name.capitalize()}"
            doSitTask.dependsOn task
        }
    }
}

两个最重要的点：

• 更换输出安装包名称由设置output.outputFile改成设置outputFileName
• 将输出apk复制到指定目录，由原来的复制output.outputFile，改成复制variant.getPackageApplicationProvider().get().outputDirectory

第二点非常重要,这一点是上面警告的根源，更改代码之后，警告就消失了。