一、管理版本号

1.在项目的build.gradle中，配置ext{}

ext {
      minSdkVersion = 16    targetSdkVersion = 23    compileSdkVersion = 23    buildToolsVersion = '23.0.2'     okhttpVersion = 'x.x.x'}

2.在项目build.gradle中引用，如okhttp

dependencies {    compile fileTree(dir: 'libs', include: ['*.jar'])    compile "com.squareup.okhttp:okhttp:$rootProject.okhttpVersion"}