我想从下拉列表中选择一个特定的名称，然后将该名称传递给控制器​​，该怎么做？

Question

我想从任务名称的下拉列表中选择特定名称，然后将其传递给控制器​​

这是我的观点

  @model MVCSecurity.Models.AssignSubTask
 <table>
  @using (Html.BeginForm())
  {
    @Html.AntiForgeryToken()


    <div class="form-horizontal">
        <h4>SubTaskModel</h4>
        <hr />
        <tr>
            <td>
                @Html.ValidationSummary(true, "", new { @class = "text-danger" })
                <div class="form-group">
                    @Html.LabelFor(model => model.SubTaskName, htmlAttributes: new { @class = "control-label col-md-2" })
                    <div class="col-md-10">
                        @Html.EditorFor(model => model.SubTaskName, new { htmlAttributes = new { @class = "form-control" } })
                        @Html.ValidationMessageFor(model => model.SubTaskName, "", new { @class = "text-danger" })
                    </div>
                </div>
            </td>
            <td> @Html.ActionLink("Create Subtask", "SubTaskCreate", "Account", null, new { style = "color:aqua" }) </td>
        </tr>
        <div class="form-group">
            Tasks:

            <div class="col-md-10">

                    @Html.DropDownListFor(m => m.TaskList, new SelectList(Model.TaskList, "Value", "Text"), new { style = "width:200px", @class = "form-control" })
                    @Html.ValidationMessageFor(model => model.TaskList)

            </div>

            </div>
        <tr>
            <td>
                <div class="form-group">

                    <div class="col-md-offset-2 col-md-10">
                        <input type="submit" value="Create" />
                    </div>

                </div>
            </td>
        </tr>
    </div>

}
 </table>
    <div style="color:red">@ViewBag.msg</div>
   <div>
    @Html.ActionLink("Back to List", "Index")
 </div>

这是我的控制人

    [HttpGet]
    public ActionResult SubTaskCreate()
    {
        AssignSubTask subTaskModel = new AssignSubTask();
        subTaskModel.TaskList = GetAll_Tasks();

        return View(subTaskModel);
    }
    [HttpPost]
    public ActionResult SubTaskCreate(SubTaskModel subTask)
    {         

        InsertSubTask(subTask);
        ViewBag.msg = "Subtask created Successfully";

        AssignSubTask subTaskModel = new AssignSubTask();
        subTaskModel.TaskList = GetAll_Tasks();

        return View(subTask);
    }

在这些方法中，我想将任务列表中的特定任务名称插入表中

    public void InsertSubTask(SubTaskModel sub)
    {
        AssignSubTask subTaskModel = new AssignSubTask();
        subTaskModel.TaskList = GetAll_Tasks();
        try
        {
            string Connectionstring = ConfigurationManager.ConnectionStrings["DBConnection"].ConnectionString;
            using (SqlConnection con = new SqlConnection(Connectionstring))
            {
                con.Open();

                using (SqlCommand cmd = new SqlCommand())
                {

                    string query = "Insert into SubTask(SubTaskName,TaskId)values(@subtaskname,(select TaskId from Task where Taskname='" + subTaskModel.TaskName + "' ))";
                    cmd.Connection = con;
                    cmd.CommandText = query;                     
                    cmd.CommandType = CommandType.Text;

                    cmd.Parameters.AddWithValue("@subtaskname", ParameterDirection.Input).Value = sub.SubTaskName;
                    cmd.Parameters.AddWithValue("@TaskName", ParameterDirection.Input).Value = sub.TaskName;
                    cmd.Parameters.AddWithValue("@TaskId", ParameterDirection.Input).Value = sub.TaskId;

                    cmd.ExecuteNonQuery();
                }
            }
        }
        catch (Exception ex)
        {

            throw ex;
        }
    }

这是我的模特

 [Table("SubTask")]
 public class SubTaskModel
 {
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int SubTaskId { get; set; }
    [Required]
    public string SubTaskName { get; set; }
    public int TaskId { get; set; }
    public string TaskName { get; set; }

    [ForeignKey("TaskId")]
    public virtual TaskModel taskmodel { get; set; }

    [ForeignKey("SubTaskId")]
    public virtual SubTaskModel HasSubTask { get; set; }


}

public class AssignSubTask
{
    public string SubTaskName { get; set; }
    public string TaskName { get; set; }
    public string UserID { get; set; }
    public List<SelectListItem> TaskList { get; set; }
    public List<SelectListItem> SubTaskList { get; set; }
}

我该怎么做？ 我想从任务名称的下拉列表中选择特定名称，然后将其传递给控制器​​

Answer 1

DropDownListFor的第一个参数是lambda表达式，您必须提供一个表达式，该表达式指示当前模型中的特定属性以进行渲染。它不能是您的数据源属性。

@Html.DropDownListFor(m => m.TaskName, new SelectList(Model.TaskList, "Value", "Text"), new { style = "width:200px", @class = "form-control" })