implementation 'com.android.support:appcompat-v4:28.0.0' 把support:appcompat 改成support:support 就好了
## Failed to resolve: com.android.support:appcompat-v4:28.0.0这个错误是V4包引来出现问题. 我原先报错时的依赖: implementation 'com.android.support:appcompat-v7:28.0.0' imp...