Android Studio3.0多渠道打包遇到的问题

最近升级到了Android Studio3.0,在给测试打包的时候突然出错，错误如下：

Error:Cannot choose between the following configurations of project :UMUpdate:
- debugApiElements
- debugRuntimeElements
- releaseApiElements
- releaseRuntimeElements
All of them match the consumer attributes:
- Configuration 'debugApiElements':
- Found com.android.build.api.attributes.BuildTypeAttr 'debug' but wasn't required.
- Found com.android.build.gradle.internal.dependency.AndroidTypeAttr 'Aar' but wasn't required.
- Found com.android.build.gradle.internal.dependency.VariantAttr 'debug' but wasn't required.
- Found org.gradle.api.attributes.Usage 'java-api' but wasn't required.
- Configuration 'debugRuntimeElements':
- Found com.android.build.api.attributes.BuildTypeAttr 'debug' but wasn't required.
- Found com.android.build.gradle.internal.dependency.AndroidTypeAttr 'Aar' but wasn't required.
- Found com.android.build.gradle.internal.dependency.VariantAttr 'debug' but wasn't required.
- Found org.gradle.api.attributes.Usage 'java-runtime' but wasn't required.
- Configuration 'releaseApiElements':
- Found com.android.build.api.attributes.BuildTypeAttr 'release' but wasn't required.
- Found com.android.build.gradle.internal.dependency.AndroidTypeAttr 'Aar' but wasn't required.
- Found com.android.build.gradle.internal.dependency.VariantAttr 'release' but wasn't required.
- Found org.gradle.api.attributes.Usage 'java-api' but wasn't required.
- Configuration 'releaseRuntimeElements':
- Found com.android.build.api.attributes.BuildTypeAttr 'release' but wasn't required.
- Found com.android.build.gradle.internal.dependency.AndroidTypeAttr 'Aar' but wasn't required.
- Found com.android.build.gradle.internal.dependency.VariantAttr 'release' but wasn't required.
- Found org.gradle.api.attributes.Usage 'java-runtime' but wasn't required.

查了以下，发现在3.0上打包的话，如果你的app moudle有几种buildTypes的话，所依赖的moudle也必须有几种（不做具体实现也可以），什么意思呢？

比如，你的app目录下的build.gradle文件中，buildTypes如下：

buildTypes {
release {
buildConfigField "boolean", "LOG_DEBUG", "false"
zipAlignEnabled true
shrinkResources true
minifyEnabled true
proguardFiles 'proguard-rules.pro'
}

debug {
buildConfigField "boolean", "LOG_DEBUG", "true"
zipAlignEnabled true
shrinkResources false
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}

debug2{

}
}

同时，你的app依赖一个第三方moudle比如叫UMUpdate，则在UMUpdate目录下的build.gradle文件中，也必须声明上边儿这三种buildTypes，当然，可以不做具体处理：

buildTypes {
release {

}

debug {

}

debug2{

}
}

更新：

以上办法在遇到依赖多个moudle的时候会非常麻烦，幸好又大佬说了一个matchingFallbacks的词，通过配置它可以处理app与moudle的依赖匹配问题。

摘抄如下：

可以通过matchingFallbacks属性来设置回退策略，提供可能的匹配列表，代码如下：

// In the app's build.gradle file.
android {
buildTypes {
debug {}
release {}
staging {
// Specifies a sorted list of fallback build types that the
// plugin should try to use when a dependency does not include a
// "staging" build type. You may specify as many fallbacks as you
// like, and the plugin selects the first build type that's
// available in the dependency.
matchingFallbacks = ['debug', 'qa', 'release']
}
}
}

若希望可以针对app的每个build type都执行相同的回退策略（例如我们大量的library只有一个release的build type），则可以使用批量指令：

buildTypes.all { type ->
type.matchingFallbacks = ['release']
}

通过这两种配置matchingFallbacks的方式，就可以通过只修改app下的build.gradle文件，来解决打包时buildTypes不匹配的问题了。