//构造函数把DBContext 作为参数，Asp.net core 框架可以自动注入DBContext对象
public CourseScoreController(ServerDBContext dbContext, INodeServices _nodeServices)
{
this.db = dbContext;
this.nodeServices = _nodeServices;
}
public AverageScoreController(ServerDBContext context)
{
db = context;
}
public NewsController(ServerDBContext context)
{
myDB = context;
}
public NetworkController(ServerDBContext context, INodeServices _nodeServices)
{
db = context;
nodeServices = _nodeServices;
}
