gradle 同步一直报这个，vpn也开了，还是不行。
修改build.gradle,注释掉jcenter()，google()。使用阿里的镜像。原因是jcenter google库无法访问到导致的问题。有时vpn也不行
buildscript {
repositories {
//google()
//jcenter()
maven { url 'https://maven.aliyun.com/repository/google' }
maven { url 'https://maven.aliyun.com/repository/jcenter' }
maven { url 'http://maven.aliyun.com/nexus/content/groups/public' }
}
dependencies {
classpath 'com.android.tools.build:gradle:3.1.2'
}
}
allprojects {
repositories {
//google()
//jcenter()
maven { url 'https://maven.aliyun.com/repository/google' }
maven { url 'https://maven.aliyun.com/repository/jcenter' }
maven { url 'http://maven.aliyun.com/nexus/content/groups/public' }
}
}