解决办法: https://stackoverflow.com/questions/49112190/error-program-type-already-present-android-support-design-widget-coordinatorl 版本降级（或者升级）
原回答：
It worked when I downgrade the support appcompat gradle dependency,like follwing:
implementation'com.android.support:appcompat-v7:27.0.2'
previously it was
implementation'com.android.support:appcompat-v7:27.1.0'
OR Also this can be fixed by just adding support design dependency to your app level build.gradle as following:
implementation'com.android.support:design:27.1.0'
原回答译文：
当我降级支持appcompatgradle依赖时，它起作用，如下所示：
implementation 'com.android.support:appcompat-v7:27.0.2'
以前是
implementation 'com.android.support:appcompat-v7:27.1.0'
要么 此外，只需将支持设计依赖项添加 到您的应用程序级别即可解决此问题build.gradle：
implementation 'com.android.support:design:27.1.0'
我的build.gradle dependencies 更改后展示
implementation 'com.android.support:design:27.0.2'
implementation 'com.android.support:appcompat-v7:27.0.2'
implementation 'com.android.support:recyclerview-v7:27.0.2'
