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我的 ASP.NET MVC Web 应用程序应该计算二次多项式（二次）的根，但我错误地得到Nan响应。我相信这是由于我的设置不正确，所以让我在这里发布一些代码：

看法：

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<RootFinder.Models.QuadCalc>" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Polynomial Root Finder - Quadratic
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <h2>Quadratic</h2>

    <% using(Html.BeginForm("Quadratic", "Calculate")) %>
    <% { %>
    <div>
        a: <%= Html.TextBox("quadAValue", Model.quadraticAValue) %>
        <br />
        b: <%= Html.TextBox("quadBValue", Model.quadraticBValue) %>
        <br />
        c: <%= Html.TextBox("quadCValue", Model.quadraticCValue) %>
        <br />
        <input type="submit" id="quadraticSubmitButton" value="Calculate!" />
        <br />
        <br />
        <strong>Root 1:</strong>
        <p><%= Model.x1 %></p>
        <br />
        <strong>Root 2:</strong>
        <p><%= Model.x2 %></p>
    </div>
    <% } %>
</asp:Content>

控制器（处理对计算请求的所有控制，如二次方）：

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

namespace RootFinder.Controllers
{
    public class CalculateController : Controller
    {
        //
        // GET: /Calculate/

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

        [HttpGet]
        public ViewResult Quadratic()
        {
            return View(new QuadCalc());
        }

        [HttpPost]
        public ViewResult Quadratic(QuadCalc newQuadCalc)
        {
            newQuadCalc.QuadCalculate();
            return View(newQuadCalc);
        }

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

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

模型（执行计算）：

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

namespace RootFinder.Models
{
    public class QuadCalc
    {
        public double quadraticAValue { get; set; }
        public double quadraticBValue { get; set; }
        public double quadraticCValue { get; set; }
        public double x1 { get; set; }
        public double x2 { get; set; }

        public void QuadCalculate()
        {
            //Quadratic Formula: x = (-b +- sqrt(b^2 - 4ac)) / 2a

            //Calculate discriminant
            double insideSquareRoot = (quadraticBValue * quadraticBValue) - 4 * quadraticAValue * quadraticCValue;

            if (insideSquareRoot < 0)
            {
                //No real solution
                x1 = double.NaN;
                x2 = double.NaN;
            }
            else if (insideSquareRoot == 0)
            {
                //One Solution
                double sqrtOneSolution = Math.Sqrt(insideSquareRoot);
                x1 = (-quadraticBValue + sqrtOneSolution) / (2 * quadraticAValue);
                x2 = double.NaN;
            }
            else if (insideSquareRoot > 0)
            {
                //Two Solutions
                double sqrtTwoSolutions = Math.Sqrt(insideSquareRoot);
                x1 = (-quadraticBValue + sqrtTwoSolutions) / (2 * quadraticAValue);
                x2 = (-quadraticBValue - sqrtTwoSolutions) / (2 * quadraticAValue);
            }
        }
    }
}

因此，假设在视图中，最终用户输入a=1，b=0然后c=0，我的应用程序将为NanRoot1 和 Root2 输出。我认为这可能是因为我没有将最终用户输入正确连接到我的 newQuadCalc 对象的实例变量中......

4

1 回答 1

2

您的代码失败，因为在网站上输入的值没有传播到您的计算逻辑。发生这种情况是因为模型绑定因文本框名称与模型属性名称不匹配而失败。您的视图应该是这样的：

<% using (Html.BeginForm("Quadratic", "Calculate")) %>
<% { %>
<div>
    a: <%= Html.TextBoxFor(m=> m.quadraticAValue) %>
    <br />
    b: <%= Html.TextBoxFor(m => m.quadraticBValue) %>
    <br />
    c: <%= Html.TextBoxFor(m => m.quadraticCValue)%>
    <br />
    <input type="submit" id="quadraticSubmitButton" value="Calculate!" />
    <br />
    <strong>Root 1:</strong>
    <p><%= Html.DisplayFor(m => m.x1) %></p>
    <br />
    <strong>Root 2:</strong>
    <p><%= Html.DisplayFor(m => m.x2)%></p>
</div>
<% } %>
于 2010-10-30T03:00:33.383 回答