多module配置version值

Android studio项目中使用多个module，全局配置version值。
根目录下的build.gradle文件下添加:

ext {
    // SDK And Tools
    minSdkVersion = 14
    targetSdkVersion = 23
    compileSdkVersion = 28
    //Dependencies
    supportLibraryVersion = '28.0.0'
}

app目录下build.gradle中使用 $rootProject.supportLibraryVersion

apply plugin: 'com.android.application'
 
android {                     
    compileSdkVersion rootProject.ext.compileSdkVersion
 
    defaultConfig {
        minSdkVersion  rootProject.ext.minSdkVersion
        targetSdkVersion rootProject.ext.targetSdkVersion
    }
}
 
dependencies {
    compile "com.android.support:cardview-v7:$rootProject.supportLibraryVersion"
}