Android编译时出现如下报错：

Build was configured to prefer settings repositories over project repositories but repository 'maven' was added by build file 'build.gradle'

原因是重复配置repositories导致的，所以解决方案就是删除多余的repositories定义，比如settings.gradle中的定义。可以全局搜索关键字：repositories，保证只在根目录的build.gradle中定义，其他gradle中的repositories定义删除即可。