ASP.NET MVC：将复杂类型绑定到选择

csharp
public class Category
{
    public int Id { get; set; }
    public string Name { get; set; }
}

csharp
public class BlogViewModel
{
    public int Id { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }
    public int CategoryId { get; set; }
    public List Categories { get; set; }
}

csharp
public class BlogController : Controller
{
    private readonly ApplicationDbContext _context;
    public BlogController(ApplicationDbContext context)
    {
        _context = context;
    }
    public IActionResult Create()
    {
        var categories = _context.Categories.ToList();
        var viewModel = new BlogViewModel
        {
            Categories = categories
        };
        
        return View(viewModel);
    }
    [HttpPost]
    public IActionResult Create(BlogViewModel viewModel)
    {
        if (ModelState.IsValid)
        {
            // 保存博客到数据库
            // ...
            return RedirectToAction("Index", "Home");
        }
        
        viewModel.Categories = _context.Categories.ToList();
        return View(viewModel);
    }
}

html
@model BlogViewModel
    
        标题