android studio gradle统一管理版本

ext {
    android = [
            compileSdkVersion    : 26,
            buildToolsVersion    : "26.0.2",
            minSdkVersion        : 15,
            targetSdkVersion     : 26,
            versionCode          : 1,
            versionName          : "1.0",
            androidSupportVersion: "26.1.0",
    ]
    dependencies = [
            "annotations"               : "com.android.support:support-annotations:${android["androidSupportVersion"]}",
            "appcompat-v7"              : "com.android.support:appcompat-v7:${android["androidSupportVersion"]}",
            "design"                    : "com.android.support:design:${android["androidSupportVersion"]}",
    ]
}

apply from : "config.gradle"

defaultConfig {
        applicationId "com.example.ma.demo"
        minSdkVersion rootProject.ext.android["minSdkVersion"]
        targetSdkVersion rootProject.ext.android["targetSdkVersion"]
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }

dependencies {
    implementation fileTree(include: [‘*.jar‘], dir: ‘libs‘)
    implementation rootProject.ext.dependencies["appcompat-v7"]
}