来自 Action 方法的 Return Json 在页面上打印 json 而不是在网格控件上显示

Question

我正尝试按照 link 中的说明运行 JQWidgets 的演示。但是当我运行演示时，我只是像这样在网页上打印 json。

这是我的 HomeController.cs

using JQWidgetGrids.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace JQWidgetGrids.Controllers
{
    [HandleError]
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            ViewData["Message"] = "Welcome to ASP.NET MVC!";

            return View();
        }

        public ActionResult DataHandler()
        {
            List<Employee> employees = EmployeesRepository.GetEmployees();

            return Json(new
            {
                employees
            },
            JsonRequestBehavior.AllowGet);
        }

        public ActionResult About()
        {
            return View();
        }
    }
}

这是DataHandler视图

@{
    ViewBag.Title = "DataHandler";
}

<title><asp:ContentPlaceHolder ID="TitleContent" /></title>
<link href="~/Content/Site.css" rel="stylesheet" type="text/css" />
<link rel="stylesheet" href="~/Content/jqx.base.css" type="text/css" />
<script type="text/javascript" src="~/Scripts/jquery-1.7.1.min.js"></script>
<script type="text/javascript" src="~/Scripts/jqxcore.js"></script>
<script type="text/javascript" src="~/Scripts/jqxdata.js"></script>
<script type="text/javascript" src="~/Scripts/jqxbuttons.js"></script>
<script type="text/javascript" src="~/Scripts/jqxscrollbar.js"></script>
<script type="text/javascript" src="~/Scripts/jqxmenu.js"></script>
<script type="text/javascript" src="~/Scripts/jqxgrid.js"></script>
<script type="text/javascript" src="~/Scripts/jqxgrid.selection.js"></script>

<h2>DataHandler</h2>

<script type="text/javascript">
    $(document).ready(function () {
        var source =
          {
              url: "Home/DataHandler",
              datatype: "json",
              datafields: [{ name: "FirstName" }, { name: "LastName" }, { name: "Product" }, { name: "Price", type: "float" }, { name: "Quantity", type: "int" }, { name: "Total", type: "float" }]
          };

        var dataAdapter = new $.jqx.dataAdapter(source);

        $("#jqxgrid").jqxGrid(
          {
              source: dataAdapter,
              columns: [
                { text: 'First Name', dataField: 'FirstName', width: 100 },
                { text: 'Last Name', dataField: 'LastName', width: 100 },
                { text: 'Product', dataField: 'Product', width: 180 },
                { text: 'Quantity', dataField: 'Quantity', width: 80, cellsalign: 'right' },
                { text: 'Unit Price', dataField: 'Price', width: 90, cellsalign: 'right', cellsformat: 'c2' },
                { text: 'Total', dataField: 'Total', cellsalign: 'right', minwidth: 100, cellsformat: 'c2' }
              ]
          });
    });
</script>
<div id="jqxgrid"></div>

这里是 Employee 模型

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

namespace JQWidgetGrids.Models
{
    public class EmployeesRepository
    {
        public static List<Employee> GetEmployees()
        {
            List<Employee> employees = new List<Employee>();

            string[] firstNames = new string[] { "Andrew", "Nancy", "Shelley", "Regina", "Yoshi", "Antoni", "Mayumi", "Ian", "Peter", "Lars", "Petra", "Martin", "Sven", "Elio", "Beate", "Cheryl", "Michael", "Guylene" };
            string[] lastNames = new string[] { "Fuller", "Davolio", "Burke", "Murphy", "Nagase", "Saavedra", "Ohno", "Devling", "Wilson", "Peterson", "Winkler", "Bein", "Petersen", "Rossi", "Vileid", "Saylor", "Bjorn", "Nodier" };
            string[] productNames = new string[] { "Black Tea", "Green Tea", "Caffe Espresso", "Doubleshot Espresso", "Caffe Latte", "White Chocolate Mocha", "Cramel Latte", "Caffe Americano", "Cappuccino", "Espresso Truffle", "Espresso con Panna", "Peppermint Mocha Twist" };
            string[] priceValues = new string[] { "2.25", "1.5", "3.0", "3.3", "4.5", "3.6", "3.8", "2.5", "5.0", "1.75", "3.25", "4.0" };
            Random random = new Random();

            for (var i = 0; i < 100; i++)
            {
                Employee employee = new Employee();

                int productindex = random.Next(productNames.Length);
                float price = float.Parse(priceValues[productindex]);
                int quantity = 1 + random.Next(10);
                employee.FirstName = firstNames[random.Next(firstNames.Length)];
                employee.LastName = firstNames[random.Next(lastNames.Length)];
                employee.Price = price;
                employee.Quantity = quantity;
                employee.Product = productNames[productindex];
                employees.Add(employee);
            }
            return employees;
        }
    }

    public class Employee
    {
        public int ID { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Product { get; set; }
        public double Price { get; set; }
        public int Quantity { get; set; }
        public double Total
        {
            get
            {
                return this.Price * this.Quantity;
            }
        }
    }
}

Answer 1

您看到该屏幕是因为您直接调用了 DataHandler() 方法（通过 link 或浏览器地址栏）。该方法的目的是 return 一个 JsonResult 供您的 jqwidget 插件使用，您不应该导航到它。

将 DataHandler.cshtml 视图的名称更改为 Index.cshtml，然后导航到 HomeController 的 Index() 方法。然后该方法将 return 您显示的视图，这将依次调用您 DataHandler() 方法来 return 数据以填充网格。

要防止直接导航到该方法，您可以使用 [AjaxOnly] only 属性修饰 DataHandler() 方法。一个典型的例子看起来像

[AttributeUsage(AttributeTargets.Method)]
public class AjaxOnlyAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        if (!filterContext.HttpContext.Request.IsAjaxRequest())
        {
            filterContext.HttpContext.Response.StatusCode = 404;
            filterContext.Result = new HttpNotFoundResult();
        }
        else
        {
            base.OnActionExecuting(filterContext);
        }
    }
}

附带说明一下，您的 DataHandler() 并不是真正需要的，您可以在初始请求中传递模型并节省第二次调用服务器的额外开销。将 Index() 方法中的代码更改为

public ActionResult DataHandler()
{
    List<Employee> model = EmployeesRepository.GetEmployees();
    return View(model );
}

然后在视图中添加

@model IEnumerable<Employee>
...

然后更改脚本以使用您使用 localdata 数据选项

传递给视图的模型

var source = {
    datatype: "json",
    datafields: [{ name: "FirstName" }, { name: "LastName" }, { name: "Product" }, { name: "Price", type: "float" }, { name: "Quantity", type: "int" }, { name: "Total", type: "float" }]
    localdata: @Html.Raw(Json.Encode(Model))
};

来自 Action 方法的 Return Json 在页面上打印 json 而不是在网格控件上显示

Return Json from Action method prints the json on page instead of showing on grid control

jquery

asp.net-mvc

jqxgrid

jqwidget