ASP.net中Core自定义View查找位置的实例代码

public class ThemeViewLocationExpander : IViewLocationExpander
  {
    public IEnumerable<string> ExpandViewLocations(ViewLocationExpanderContext context, IEnumerable<string> viewLocations)
    {
      string theme = context.Values["theme"];
      if (string.IsNullOrWhiteSpace(theme))
      {
        theme = "default";
      }
      string[] newLocation = { $"Views/{theme}/{{1}}/{{0}}.cshtml"};
      return viewLocations.Union(newLocation);
    }

    public void PopulateValues(ViewLocationExpanderContext context)
    {
      context.Values["theme"] = context.ActionContext.HttpContext.Request.Query["theme"].ToString();
    }
  }

//配置模版视图路径
      services.Configure<RazorViewEngineOptions>(options =>
      {
        options.ViewLocationExpanders.Add(new ThemeViewLocationExpander());
      });