Question

我使用UseCaseId和ExtensionPoint的模型值填充我的视图 - 通过此调试似乎工作正常。

但是，当我向视图中的ExtensionTitle字段添加新信息然后POST时，只会保留ExtensionTitle的值以及UseCaseId和{的值{1}}丢失了。这意味着ExtensionPoint返回false，因此我无法将新记录保存到数据库中。

有人可以告诉我为什么这些值会在我if (ModelState.IsValid)时迷失吗？

视图模型

POST

MODEL

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Web;

namespace JustSpecIt.ViewModels
{
    public class AddExtensionStepViewModel
    {

        public int UseCaseId { get; set; }
        [DisplayName ("Extends Step #")]
        public int ExtensionPoint { get; set; }
        [DisplayName ("Extends Step Description")]
        public string StepTitle { get; set; }
        [DisplayName("Extension Name")]
        public string ExtensionTitle { get; set; }

    }
}

CONTROLLER

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace JustSpecIt.Models
{
    public class Extension
    {
        public int ID { get; set; }
        public int UseCaseID { get; set; }
        public string Title { get; set; }
        public int ExtensionPoint { get; set; }
    }
}

查看

 // GET: Extensions/Create
        public ActionResult Create(int id)
        {
            ViewBag.UseCaseId = id;
            ViewBag.StepTitle = db.Steps.Find(id).Content;

            //Create an populate the ViewModel
            AddExtensionStepViewModel model = new AddExtensionStepViewModel()
            {
                ExtensionPoint = id,
                UseCaseId = db.Steps.Find(id).UseCaseID,


            };

            return View();
        }

        // POST: Extensions/Create
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "UseCaseId,ExtensionTitle,ExtensionPoint")] AddExtensionStepViewModel model)
        {
            if (ModelState.IsValid)
            {
                Extension e = new Extension ();
                e.ExtensionPoint = model.ExtensionPoint;
                e.UseCaseID = model.UseCaseId;
                e.Title = model.ExtensionTitle;

                db.Extensions.Add(e);
                db.SaveChanges();
                return RedirectToAction("ChooseExtensionStep", new { id = model.UseCaseId });
            }

            return View(model);
        }

Answer 1

您尚未将模型传递给GET方法中的视图（因此UseCaseID和Title的值为0（int的默认值）

public ActionResult Create(int id)
{
  ViewBag.UseCaseId = id;
  ViewBag.StepTitle = db.Steps.Find(id).Content;
  AddExtensionStepViewModel model = new AddExtensionStepViewModel()
  {
    ExtensionPoint = id,
    UseCaseId = db.Steps.Find(id).UseCaseID,
  };
  return View(model); // change this
}

POST动作丢失值

1 个答案: