显示列表 return 从控制器到视图 ASP.NET 中的 table MVC4

Question

我的控制器 class 中有一个函数，它 return 一个数据列表，我想在我的视图页面中以 table 结构显示它。我试过下面的代码，但它显示了一些错误

"Class does not contain definition of GetEnumerator"

控制器

public ActionResult data(Message msg,IEnumerable<sample> dept)
{
    dbconnection db = new dbconnection();
    sample s = new sample();
    SqlConnection con = new SqlConnection(db.GetconString());
    DataTable dt;   
    List<examplemvc1.Models.sample> datatable = new List<sample>();
    dt = db.BuildDT("select * from MVCsample");
    foreach (DataRow row in dt.Rows)
    {
        s.FirstName = Convert.ToString(row["First Name"]);
        s.LastName = Convert.ToString(row["Last Name"]);
        s.Address = Convert.ToString(row["Address"]);
        s.PhoneNumber = Convert.ToString(row["PhoneNumber"]);
        s.Location = Convert.ToString(row["Location"]);
        datatable.Add(s);
        dept = datatable;  
    }
    ViewBag.tabledata = dept;
    return View(dept) ;
}

型号

public class sample
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Address { get; set; }
    public string PhoneNumber { get; set; }
    public string Location { get; set; }
    public string tabledata { get; set; }
}

public class Message
{
    public IEnumerable<sample> sampleList { get; set; }
    public string MessageText { get; set; }
    public string MessageFrom { get; set; }
}

查看

@model examplemvc1.Models.sample

@foreach (var data in Model)
{
    <table><tr><td>@data.FirstName</td></tr></table>
}

更新这就是我的整个视图

@model List<examplemvc1.Models.sample>
@{
    ViewBag.Title = "Registration Form";
}
<head>
    <script type="text/javascript" src="../../Scripts/jquery-1.7.1.min.js"></script>
    <link href="../../Style/sample.css" rel="stylesheet" type="text/css" />
    <script src="../../Scripts/samplescript.js" type="text/javascript"></script>
</head>
<h2>
    Registration Form </h2>
   <body>

  <table>
 <tr>
 <th>
   First Name
 </th>
 </tr>

@foreach (var data in Model)
{
    <tr><td>@data.FirstName</td></tr>
}
</table>



@using (Html.BeginForm())
{

    <table id="table1">
    <tr>
         <td> 

             @Html.Label("Enter FirstName", new { @class = "standard_label_style" })
        </td>
         <td>
             @Html.TextBoxFor(a => a.FirstName, new { @class = "class1", title = "Enter FirstName", id = "NameBox", placeholder = "Enter name", onkeydown = "return TextField(event)" })
          <span class="errorMessage"></span>
           @if (!ViewData.ModelState.IsValid)
           {       
                <span class="field-validation-error">
                @ViewData.ModelState["FirstName"].Errors[0].ErrorMessage</span>
           }     
    </td>
    </tr>


    <tr>
    <td>
    @Html.Label("Enter LastName", new { @class = "standard_label_style" })
    </td>
    <td>

    @Html.TextBoxFor(a => a.LastName, new { @class = "class1", placeholder = "Enter name", id = "LastNameBox", title = "Enter Lastname", onkeydown = "return TextField(event); " })
        <span class="errorMessage"></span>
       </td>
    </tr>
    <tr>
    <td>
     @Html.Label("Enter Address", new { @class = "standard_label_style" })
     </td>
     <td>
      @Html.TextBoxFor(a => a.Address, new { @class = "class1", id = "AddressBox", placeholder = "Enter name", title = "Enter Address" })
    <span class="errorMessage"></span>
   </td>
    </tr>
    <tr>
   <td>
    @Html.Label("Enter PhoneNumber", new { @class = "standard_label_style" })
    </td>
    <td>
    @Html.TextBoxFor(a => a.PhoneNumber, new { @class = "class1", id = "PhoneBox", placeholder = "Enter name", title = "Enter Phonenumber", onkeydown = "return ValidateNumber(event);" })
    <span class="errorMessage"></span>
    </td>
  </tr>
  <tr>
  <td>
    @Html.Label("Enter Location", new { @class = "standard_label_style" })
    </td><td>
      @Html.TextBoxFor(a => a.Location, new { @class = "class1", id = "LocationBox", placeholder = "Enter name", title = "Enter Location" })
      <span class="errorMessage"></span>
      </td>
     </tr>
   </table>
    <input type="button" id="btnSave"  value="Register"/>
     <input type="button" value="Clear"/>
     <input type="button" id="Tabledata" value="Tabledata"/>
    <div id="div1"></div>

   @*@Html.ValidationSummary()*@








   <script type="text/javascript">

       function ValidateNumber(e) {
           var evt = (e) ? e : window.event;
           var charCode = (evt.keyCode) ? evt.keyCode : evt.which;
           if (charCode > 31 && (charCode < 48 || charCode > 57)) {
               return false;
           }
           return true;
       };
       function TextField(e) {
           var evt = (e) ? e : window.event;
           var charCode = (evt.keyCode) ? evt.keyCode : evt.which;
           if (charCode > 31 && (charCode < 48 || charCode > 56)) {
               return true;
           }
           else if (charCode == 8 || charCode == 9) {
               return true;
           }
           return false

       };


   </script>

}
   </body>

我的视图代码中显示错误，实际上我不知道如何在视图页面中获取该值。我是 mvc 的新手。请帮我解决这个问题。任何帮助将不胜感激。

"Update"

我已经在 Whosebug 的帮助下解决了我的问题下面是我的正确代码

控制器

 public ActionResult data()
        {
            SomeViewModel model = new SomeViewModel();
            dbconnection db = new dbconnection();
            SqlConnection con = new SqlConnection(db.GetconString());
            DataTable dt = db.BuildDT("select * from MVCsample");
            foreach (DataRow row in dt.Rows)
            {
                sample s = new sample();
                s.FirstName = Convert.ToString(row["First Name"]);
                s.LastName = Convert.ToString(row["Last Name"]);
                s.Address = Convert.ToString(row["Address"]);
                s.PhoneNumber = Convert.ToString(row["PhoneNumber"]);
                s.Location = Convert.ToString(row["Location"]);
                model.samples.Add(s);
            }
            return View(model);
        }

型号

namespace examplemvc1.Models
{
    public class sample
    {

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public string Address { get; set; }


        public string PhoneNumber { get; set; }

        public string Location { get; set; }
         public string tabledata { get; set; }

    }
    public class Message
    {
        public IEnumerable<sample> sampleList { get; set; }
        public string MessageText { get; set; }
        public string MessageFrom { get; set; }
    }
    public class SomeViewModel
    {
        public SomeViewModel()
        {
            samples = new List<sample>();
            sample = new sample();
        }
        public List<sample> samples { get; set; }
        public sample sample { get; set; }
    }
}

查看

@model examplemvc1.Models.SomeViewModel

//................

@foreach (var data in Model.samples)
{
    <tr><td>@data.FirstName</td>
     <td>@data.LastName</td>
     <td>@data.Address</td>
     <td>@data.PhoneNumber</td>
     <td>@data.Location</td></tr>
}
</table>

看看下面 Stephen Muecke 的回答，他把上下文解释得很清楚了

Answer 1

问题是您的模型是 examplemvc1.Models.sample 类型，而您必须传递 List<examplemvc1.Models.sample> 的对象才能查看：

 return View(datatable) ;

您的操作：

List <examplemvc1.Models.sample> datatable = new List<sample>();

dt = db.BuildDT("select * from MVCsample");
    foreach (DataRow row in dt.Rows)
    {
       s.FirstName = Convert.ToString(row["First Name"]);
       s.LastName = Convert.ToString(row["Last Name"]);
       s.Address = Convert.ToString(row["Address"]);
       s.PhoneNumber = Convert.ToString(row["PhoneNumber"]);
       s.Location = Convert.ToString(row["Location"]);
       datatable.Add(s);
    }


    return View(datatable);  // passing list to view

并在视图中将模型设置为 List<examplemvc1.Models.sample>:

@model List<examplemvc1.Models.sample>

现在重复您的操作方式：

<table>
 <thead>
 <tr><th>First Name</th></tr>
 </thead>
 <tbody>
@foreach (var data in Model)
{
    <tr><td>@data.FirstName</td></tr>
}
</tbody>
</table>

Answer 2

问题出在你的模型指令上。

应该是

@model IEnumerable<examplemvc1.Models.sample>

而不是

@model examplemvc1.Models.sample

注意：您像dept = datatable;一样进行了几次赋值，您可以像这样更新代码。

public ActionResult data(Message msg,IEnumerable<sample> dept)
    {

        dbconnection db = new dbconnection();
        sample s = new sample();
       SqlConnection con = new SqlConnection(db.GetconString());
        DataTable dt;

            List <examplemvc1.Models.sample> datatable = new List<sample>();

           dt = db.BuildDT("select * from MVCsample");
           foreach (DataRow row in dt.Rows)
           {
               s.FirstName = Convert.ToString(row["First Name"]);
               s.LastName = Convert.ToString(row["Last Name"]);
               s.Address = Convert.ToString(row["Address"]);
               s.PhoneNumber = Convert.ToString(row["PhoneNumber"]);
               s.Location = Convert.ToString(row["Location"]);
               datatable.Add(s);

              //dept = datatable;

           }
            ViewBag.tabledata = datatable;

            return View(datatable) ;
    }

更新在这种情况下，您需要先创建视图模型并将其实例作为模型传递到那里。

public class SomeViewModel
{
    public SomeViewModel()
    {
        samples = new List<sample>();
        sample = new sample();
    }
    public List<sample> samples {get; set;}
    public sample sample {get; set;}
}

并在模型声明中

@model namespace.SomeViewModel

然后在控制器中如下所示。

public ActionResult data(Message msg,IEnumerable<sample> dept)
{
    dbconnection db = new dbconnection();
    sample s = new sample();
    SqlConnection con = new SqlConnection(db.GetconString());
    DataTable dt;   
    List<examplemvc1.Models.sample> datatable = new List<sample>();
    dt = db.BuildDT("select * from MVCsample");
    foreach (DataRow row in dt.Rows)
    {
        s.FirstName = Convert.ToString(row["First Name"]);
        s.LastName = Convert.ToString(row["Last Name"]);
        s.Address = Convert.ToString(row["Address"]);
        s.PhoneNumber = Convert.ToString(row["PhoneNumber"]);
        s.Location = Convert.ToString(row["Location"]);
        datatable.Add(s);
        dept = datatable;  
    }
    ViewBag.tabledata = dept;
    SomeViewModel vm = new SomeViewModel();
    vm.samples = datatable;
    vm.sample = //somesample instance here you want to edit.

    return View(vm) ;
}

在视图中，您将通过 vm.samples

获得 vm 迭代实例

@foreach (var data in Model.samples)
{
    <tr><td>@data.FirstName</td></tr>
}

并在其余视图中执行如下操作：

@Html.TextBoxFor(a => a.sample.FirstName, new { @class = "class1", title = 
"Enter FirstName", id = "NameBox", placeholder = "Enter name", onkeydown = 
"return TextField(event)" })

Answer 3

您的视图显示的是 sample 的列表和似乎是新 sample 的表单。首先创建一个视图模型来表示您想要的内容 display/edit

public class SampleVM
{
  public SampleVM
  {
      SampleCollection = new List<sample>
  }
  public List<sample> SampleCollection { get; set; }
  public sample NewSample { get; set; }
}

在您的控制器中将代码修改为

public ActionResult data()
{
    SampleVM model = new SampleVM();
    dbconnection db = new dbconnection();
    SqlConnection con = new SqlConnection(db.GetconString());
    DataTable dt = db.BuildDT("select * from MVCsample");
    foreach (DataRow row in dt.Rows)
    {
        sample s = new sample();
        s.FirstName = Convert.ToString(row["First Name"]);
        s.LastName = Convert.ToString(row["Last Name"]);
        s.Address = Convert.ToString(row["Address"]);
        s.PhoneNumber = Convert.ToString(row["PhoneNumber"]);
        s.Location = Convert.ToString(row["Location"]);
        model.SampleCollection.Add(s);
    }
    return View(model);
}

备注：

从 GET 方法中删除参数。除了你不要使用它们，所以它们毫无意义，即使你尝试过将这些对象传递给方法，绑定将失败并且 collections 将为空（如果你要构建正确的查询字符串以使其工作，它会很长，几乎肯定会抛出异常）
您需要在 foreach 循环中初始化一个新的 sample （您的代码只初始化了一个对象，并且每个循环都更新了它的属性添加到当前行，所以你最终会得到多个同一个对象的引用，都匹配最后一个的值在你的 table)
无需将模型作为 ViewBag 属性（其已经使用 return View(model);

并将您的视图修改为

@model SampleVM
....
<table>
    @foreach(var sample in Model.SampleCollection)
        <tr>
            <td>@sample .FirstName</td>
        </tr>
    }
</table>
@Html.BeginForm())
{
  @Html.LabelFor(m => m.NewSample.FirstName, "Enter FirstName", new { @class = "standard_label_style" })
  @Html.TextBoxFor(m => m.NewSample.FirstName, @class = "class1", placeholder = "Enter name", title = "Enter Lastname")
  @Html.ValidationMessageFor(m => m.NewSample.FirstName)
}
....
<input type="submit" id="btnSave"  value="Register"/>

备注：

用于将元素与控件相关联的标签元素。您的使用会生成 <label for="Enter_FirstName"> 但您没有用 id="Enter_FirstName" 控制。最好你应该有 [Display(Name = "Enter FirstName")] 在属性上，否则使用强类型助手
使用@Html.ValidationMessageFor()渲染ModelState错误，虽然在你的情况下你所有的属性都是字符串而你没有有任何验证属性，所以永远不会有任何错误，所以这有点毫无意义
html 助手生成一个 id 属性。很少需要覆盖它。停止用行为污染你的标记并学习使用 Unobtrusive Javascript
您的表单不包含提交按钮

显示列表 return 从控制器到视图 ASP.NET 中的 table MVC4

Display List return from a controller to a table in view ASP.NET MVC4

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