.NET CORE project start page

The web page (e.g. index.html ) in wwwroot under (wwwroot must be placed), then Startup.cs files  public void Configure (IApplicationBuilder app, IHostingEnvironment  env) method in the following two ways to add one kind i.e. can

//1
DefaultFilesOptions defaultFilesOptions = new DefaultFilesOptions();
defaultFilesOptions.DefaultFileNames.Clear();
defaultFilesOptions.DefaultFileNames.Add("index.html");
app.UseDefaultFiles(defaultFilesOptions);
app.UseStaticFiles(); 

//或者

//2
FileServerOptions fileServerOptions = new FileServerOptions();
fileServerOptions.DefaultFilesOptions.DefaultFileNames.Clear();
fileServerOptions.DefaultFilesOptions.DefaultFileNames.Add("index.html");
app.UseFileServer(fileServerOptions);