C# MVC模型绑定和自定义绑定(详细介绍)

   //系统自带绑定
   //Bind特性有三个属性，Include="包含字段"；Prefix="含有字符串的字段"；Exclude="不包含的字段"
    public class UsersController : Controller
    {
        //可写在参数中
        public ActionResult usersBind([Bind(Include = "UserName,Pwd",Prefix ="P",Exclude ="Id")]User user)
        {
            User users = new Models.User();
            //可调用UpdateModel方法事项绑定 ，代码手动编写比较灵活
            UpdateModel<User>(users, new string[] { "Id", "UserName" });
            return View();
        }

    }
    //也可写在类上面
    [Bind(Include = "UserName,Pwd", Prefix = "P", Exclude = "Id")]
    public class User
    {
        public int Id { get; set; }
        public string UserName { get; set; }
        public string Pwd { get; set; }

    }
  //自定义绑定
  public class MvcApplication : System.Web.HttpApplication
    {
        //在Application_Start中声明绑定
        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
            ModelBinders.Binders.Add(typeof(User),new UserBinder());//通过ModelBinders调用绑定
        }
    }
 //继承接口IModelBinder实现BindModel()方法，来完成自定义绑定，可自定义改变规则
    public class UserBinder : IModelBinder
    {
        public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
        {
            var User = (User)bindingContext.Model ?? new User();
            User.Id = GetVaule<int>(bindingContext, "Id");
            string name = GetVaule<string>(bindingContext, "UserName");
            User.Pwd = GetVaule<string>(bindingContext, "Pwd");
            User.UserName = name + "ai";//如返回值结果多加个"ai"
            return User;
        }

        public T GetVaule<T>(ModelBindingContext bindingContext, string key)
        {
            ValueProviderResult valueResult = bindingContext.ValueProvider.GetValue(key);
            return (T)valueResult.ConvertTo(typeof(T));
        }
    }
   //调用执行Action前，会先执行绑定
     public ActionResult userBind(User user)
        {
            return View();
        }