Question

我在浏览页面上编辑记录时遇到问题;我得到了编辑页面，但记录不在该字段中。找到身份后，我不确定;如何从视图中获取记录

查看

<h4>Student</h4>
<hr />
<div class="form-group">
    <table>
        <tr>
            <th class="col-m2-1">Student Number</th>
            <th class="col-md-2"> Name</th>
        </tr>
        if (@Model.items.Count > 0)
        {
            foreach (var issueditem in @Model.items)
            {
                <tr>
                    <td class="col-md-2">@item.studentNumber</td>
                    <td class="col-md-2">@item.Name</td>
                    <td>
                        @Html.ActionLink("Edit", "Edit", new { id = item.lineNum }) |
                        @Html.ActionLink("Remove", "Remove", new { id = item.lineNum }, new { onclick = "return confirm('Are you sure you would like to remove this item?');" })
                    </td>
                </tr>
            }
        }

控制器

public ActionResult Edit(int id)
{
    IssueDAO dbData = new IssueDAO();

    Item item = new Item();

    return View(dbData.GetStudent().Find(smodel => smodel.id == id));
}

方法

public List<StudentModel> GetStudent()
{
    connection();

    List<StudentModel> studentlist = new List<StudentModel>();

    SqlCommand cmd = new SqlCommand("GetStudentDetails", con);
    cmd.CommandType = CommandType.StoredProcedure;

    SqlDataAdapter sd = new SqlDataAdapter(cmd);
    DataTable dt = new DataTable();

    con.Open();
    sd.Fill(dt);
    con.Close();

    foreach(DataRow dr in dt.Rows)
    {
         studentlist.Add(new StudentModel
                             {
                                 Id = Convert.ToInt32(dr["Id"]),
                                 Name = Convert.ToString(dr["Name"])
                             });
    }

    return studentlist;
}

Answer 1

您的观点需要model指令。

@model StudentModel

这将确保Razor可以将@Model绑定到您从控制器返回的任何类型。

其他一些最终会导致您共享的代码段出现问题：

//references to @item should be @issueditem or this code will fail.
foreach (var issueditem in @Model.items)
{
    <tr>
        <td class="col-md-2">@issueditem.studentNumber</td> //@item should be @issueditem
        <td class="col-md-2">@issueditem.Name</td>
        <td>
            @Html.ActionLink("Edit", "Edit", new { id = issueditem.lineNum }) |
            @Html.ActionLink("Remove", "Remove", new { id = issueditem.lineNum }, new { onclick = "return confirm('Are you sure you would like to remove this item?');" })
        </td>
    </tr>
}

Answer 2

请根据您的要求更改代码，以下代码仅供参考。

第1步：首先为修改方法创建视图。

    @model StudentModel; //Give reference model as per your code

    @using (Html.BeginForm("Controller Name", "Update", FormMethod.Post))
    {

<h4>Form Title</h4>
<hr />

<div class="form-group">
    @Html.LabelFor(m => m.Id, new { @class = "col-md-2 control-label" })
    <div class="col-md-10">
        @Html.TextBoxFor(m => m.Id, new { @class = "form-control" })
    </div>
</div>
<div class="form-group">
    @Html.LabelFor(m => m.Name, new { @class = "col-md-2 control-label" })
    <div class="col-md-10">
        @Html.TextBoxFor(m => m.Name, new { @class = "form-control" })
    </div>
</div>
<div class="form-group">
    <div class="col-md-offset-2 col-md-10">
        <input type="submit" value="Change password" class="btn btn-default" />
    </div>
</div>
}

步骤2：在Controller中添加以下方法

    public ActionResult Update(StudentModel stuModel)
    {
        SqlConnection con = new SqlConnection(strConnString);
        SqlCommand cmd = new SqlCommand();
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.CommandText = "Update Procedure";
        cmd.Parameters.Add("@Id", SqlDbType.Int).Value = stuModel.Id;
        cmd.Parameters.Add("@Name", SqlDbType.VarChar).Value = stuModel.Name;
        cmd.Connection = con;
        try
        {
            con.Open();
            cmd.ExecuteNonQuery();
            lblMessage.Text = "Record updated successfully";
        }
        catch (Exception ex)
        {
        }
        finally
        {
            con.Close();
            con.Dispose();
        }

        return RedirectToAction("Index");
    }

第3步：请使用 firstorDefault 方法查找模型对象，如下所示。

       public ActionResult Edit(int id)
    {
        IssueDAO dbData = new IssueDAO();

        Item item = new Item();

        //Model is same type which you passed in Edit View => StudentModel
        var Model = dbData.Students
                   .where(s => s.id == id)
                   .FirstOrDefault<StudentModel>();

        return View(Model); 
    }

不使用Entity Framework更新记录

2 个答案: