Method:
1. File> Project Structure (the Command +;)> Under Project Settings / Project> the Set Project Platform SDK to Android API 29 (1.file> Project Structure (the Command +;)> under Project Settings / Project> The Project SDK to Android API 29 Platform)
.2. There should be a notification stating there is an invalid item in the dependencies list under Project Structure/Problems. If there is, go to Project Structure > Under Project Settings/Modules > select app_name_android > Dependencies tab > choose the latest "Android API 29 Platform" in the Module SDK box.(应该有一个通知，指出依赖项列表中“项目结构/问题”下的项目无效。如果存在，请转到“项目结构”>“项目设置/模块”下，选择“ app_name_android”>“依赖项”选项卡，然后在“模块SDK”框中选择最新的“ Android API 29平台”)
3.Update GradleException () to FileNotFoundException () under android / app / build_gradle since it's not supported in the Java version of Android API 29That's it! You should notice the Android API 29 Platform is now visible under External Libraries. (The GradleException () FileNotFoundException updated at android / app / build_gradle (), because Java version of the Java API does not support the 29 it! You should note, Android API 29 platform is now visible in the "external library.")
