我如何在 MVC 中重载索引

Question

我有索引页面，其中包含来自数据库的博客。首先，如果我不提供类别 ID，那么所有博客都必须进入索引页面。如果我给出类别，那么我想按类别 ID 显示博客，所以我需要使用索引重载。

public ActionResult Index(){List<Blog> blogs = db.Blogs.ToList();}
public ActionResult Index(int ID){List<Blog> blogs = db.Blogs.Where(x=>x.CategoryID==ID).ToList();}

但是当我想显示所有博客时，错误是这样的：

The current request for action 'Index' on controller type 'HomeController' is ambiguous between the following action methods: System.Web.Mvc.ActionResult Index() on type SosyalSozluk.Areas.Blog.Controllers.HomeController System.Web.Mvc.ActionResult Index(Int32) on type SosyalSozluk.Areas.Blog.Controllers.HomeController

Answer 1

删除第一个方法并更改第二个方法使参数可选

public ActionResult Index(int? ID)
{
    IEnumerable<Blog> blogs = db.Blogs;
    if (ID.HasValue)
    {
        blogs = blogs .Where(x=>x.CategoryID == ID.Value);
    }
    return View(model); // add `.ToList()` if you really need it
}