---

由2.3.1升级到3.0需要做以下改动：

1. 工程的build.gradle下：

• gradle插件需要变为2.3.0以上的版本;
• jcenter()下面要添加一行google();

buildscript {
    repositories {
        mavenCentral()
        jcenter()
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.0'
        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.7.7'
    }
}
allprojects {
    repositories {
        jcenter()
        google()
    }

    gradle.projectsEvaluated {
        tasks.withType(JavaCompile) {
            options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation"
        }
    }
}
task clean(type: Delete) {
    delete rootProject.buildDir
}

2. 应用app的build.gradle下：

• 修改buildToolsVersion的版本为25.0.0以上；

android {
    compileSdkVersion 'Google Inc.:Google APIs:24'
    buildToolsVersion '25.0.0'

3. gradle的编译版本：

gradle的编译版本需要改为4.1；

#Wed Sep 21 11:05:06 CST 2016
distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists
distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip