自动提示是默认开启的，gradle的语法就是groovy语法的极简写法，你可以指针选择后按ctrl+B即可跳到对应的gradle源代码上，gradle api请参考官方文档。

Gradle looks for gradle.properties files is these places:

in project build dir (that is where your build script is)

in sub-project dir

in gradle user home (defined by the GRADLE_USER_HOME environment variable, which if not set defaults to USER_HOME/.gradle)

Properties from one file will override the properties from the previous ones (so file in gradle user home has precedence over the others, and file in sub-project has precedence over the one in project root).

Reference: https://gradle.org/docs/current/userguide/build_environment.html

试试在$MAVNE_HOME/settings.xml中把阿里云的源添加到第一个位置试试