报错： ERROR in : Type RecommendComponent in E:/2018/KYLIN-WEB/src/app/home/article-details/recommend/recommend.component.ts is part of the declarations of 2 modules: ArticleDetailsModule in E:/2018/KYLIN-WEB/src/app/home/article-details/article-details.module.ts and RecommendModule in E:/2018/KYLIN-WEB/src/app/home/article-details/recommend/recommend.module.ts! Please consider moving RecommendComponent in E:/2018/KYLIN-WEB/src/app/home/article-details/recommend/recommend.component.ts to a higher module that imports ArticleDetailsModule in E:/2018/KYLIN-WEB/src/app/home/article-details/article-details.module.ts and RecommendModule in E:/2018/KYLIN-WEB/src/app/home/article-details/recommend/recommend.module.ts. You can also create a new NgModule that exports and includes RecommendComponent in E:/2018/KYLIN-WEB/src/app/home/article-details/recommend/recommend.component.ts then import that NgModule in ArticleDetailsModule in E:/2018/KYLIN-WEB/src/app/home/article-details/article-details.module.ts and RecommendModule in E:/2018/KYLIN-WEB/src/app/home/article-details/recommend/recommend.module.ts.
article-details模块有四个子模块
刚开始的引用
article-details模块：
四个模块引入各自的component，用其中一个子模块recommend.module为例
于是打包时报错
翻译了一下
就是组件只能声明在一个模块里面
改进
把所有的组件声明在article-details模块里面，子模块不用再引入，每个子模块只需要引入article-details模块就可以了
这里是以其中一个子模块为例，其他三个也相同的操作
这样就可以通过编译了！