您已经为您的应用选择了多种外形，如下所示.

You have selected multiple form factors for your app like below.

这就是为什么它显示 mobile 和 wear 文件夹而不是 app 的原因.因此，现在只需双击 mobile 文件夹，您将获得应用级别的 build.gradle 文件.wear 文件夹也是如此.

That's why it's showing mobile and wear folders instead of app. So, now just double click on mobile folder you will get app level build.gradle file. Same thing for the wear folder.

如果您只想开发移动应用程序，那么您不必在创建项目时选择 wear 外形.然后你在你的项目中只会得到 app 文件夹.

If you want only mobile app development then you don't have to select wear form factor while creating the project. Then you only get app folder in your project.