使用 ajax 和 json 的 C# MVC 更新数据库

Question

我在 C# MVC 视图上有一个简单的表单。表单收集用户的名字和姓氏，然后将数据发送给控制器。这是表格的样子：

<div class="col-md-12">
<div class="col-md-4"></div>
<div class="col-md-4">
    <div class="col-md-12">
        <label>First Name :</label>
        <input class="form-control required" type="text" id="txtFirstName" required />
    </div>
    <div class="col-md-12">
        <label>Last Name :</label>
        <input class="form-control required" type="text" id="txtLastName" required />
    </div>
    <div class="col-md-12">
        <br />
        <input id="btnSave" class="btn btn-success" type="button" value="Save Product" />
        <input id="btnCancel" class="btn btn-danger" type="button" value="Cancel" />
    </div>
</div>
</div>

<div id="dvLoader" class="LoadingDiv" style="display: none;">
<table style="height: 100%; margin: auto;">
    <tr>
        <td style="vertical-align: middle;">
            <center>
                <img src="..\..\Images\loading-icegif.gif" alt="Loading" />
            </center>
        </td>
    </tr>
</table>
</div>

我有这个 ajax 代码：

        $(function () {
        $('#btnSave').on('click', function () {
            var FirstName = $("#txtFirstName").val();
            var LastName = $("#txtLastName").val();
            if (CheckRequiredFields()) {
                $('#dvLoader').show();
                $.ajax({
                    url: '@Url.Action("SaveAndUpdateProduct", "Home")',
                        type: 'POST',
                        data: JSON.stringify({ "FirstName": FirstName, "LastName": LastName }),
                        dataType: "json",
                        contentType: "application/json; charset=utf-8",
                        success: function (result) {
                            $('#dvLoader').hide();

                            if (result.Status == "True") {
                                toastr.success(result.Message);
                                clear();
                                display();
                            }
                            else {
                                toastr.success(result.Message);
                                clear();
                                display();

                            }
                        }
                    });
            }
        });
    });

而且，这是 HomeController.cs:

using CodingChallengeV4.Models;
using Docker.DotNet.Models;
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace CodingChallengeV4.Controllers
{
public class HomeController : Controller
{
    public ActionResult Index()
    {
        using (var ctx = new ContactContext())
        {
            var seedContact = new ContactOrig();
            seedContact.FirstName = "seelFirst";
            seedContact.LastName = "seedLast";

            ctx.Contact.Add(seedContact);
            ctx.SaveChanges();
        }
        return View();
    }

    public ActionResult About()
    {
        ViewBag.Message = "Your application description page.";
        return View();
    }

    public ActionResult Contact()
    {
        ViewBag.Message = "Your contact page.";

        return View();
    }
    public JsonResult SaveAndUpdate(string FirstName, string LastName)
    {
        var result = new JSONMessage();
        try
        {
            using (var ctx = new ContactContext())
            {
                //define the model  

                var contact = new ContactOrig();
                contact.FirstName = FirstName;
                contact.LastName = LastName;

                ctx.Contact.Add(contact);
                result.Status = "true";
                result.ErrorMessage = "your product has been updated successfully..";
                ctx.SaveChanges();
            }

        }
        catch (Exception ex)
        {
            result.ErrorMessage = "We are unable to process your request at this time. Please try again later.";
            result.Status = "false";
        }
        return Json(result, JsonRequestBehavior.AllowGet);
    }
}

}

当我执行代码并输入名字和姓氏并单击“保存”按钮时，会显示 dvLoader，但我在控制台中收到此错误：

POST http://localhost:4093/Home/SaveAndUpdateProduct 500 (Internal Server Error)

知道为什么 post 会产生这个错误吗？

谢谢！

Answer 1

首先，最好创建一个视图模型

public class NameViewModel
{
      public string FirstName {get; set;}
      public string LastName {get; set;}
}

尝试从 ajax

中删除内容类型：“application/json; charset=utf-8”

$.ajax({
    url: "/Home/SaveAndUpdateProduct",
      type: 'POST',
       data: { FirstName: FirstName, LastName: LastName },
       dataType: "json",

并修正动作

 public JsonResult SaveAndUpdateProduct(NameViewModel model)

使用 ajax 和 json 的 C# MVC 更新数据库

C# MVC update database with ajax and json

c#

json

ajax

asp.net-mvc