项目结构（File->Project Structure）
既然是灰色，说明有问题。
设置（File->Setting）
修改设置
打开local.properties，添加刚刚下载的ndk：
## This file must *NOT* be checked into Version Control Systems, # as it contains information specific to your local configuration. # # Location of the SDK. This is only used by Gradle. # For customization when using a Version Control System, please read the # header note. #Tue May 31 21:35:41 CST 2022 sdk.dir=D\:\\SOFTWARES\\DEVELOP\\adt-bundle-windows-x86_64-20190307\\sdk ndk.dir=D\:\\SOFTWARES\\DEVELOP\\adt-bundle-windows-x86_64-20190307\\sdk\\ndk\\21.0.6113669
