Question

我正在制作一个简单的语气应用,有两个实体:tasks和categories。

为创建<条码>task,选择<条码>类别是必须的。为此,我表示,我需要一个观点。

这里是工作队实体。

public class Task
{
    public int taskId { get; set; }
    public int categoryId { get; set; }
    public string taskName { get; set; }
    public bool isCompleted { get; set; }
    public DateTime creationDate { get; set; }
    public DateTime completionDate { get; set; }
    public string remarks { get; set; }
    public string completionRemarks { get; set; }
}

本类实体

public class Category
{
    public int categoryId { get; set; }
    public string categoryName { get; set; }
}

我如何设计<代码> 缩略语因此,我可以对<代码><> 类别/代码>在<代码>上的约束?

<><>Edit>: 我正在使用传统的《反歧视法》。 NET而不是实体框架或LINQ至Q。

Answer 1

Kishor,

最好有模式,为你的任务和类别(均为一类)下定义。

这里,所有东西如何一起hang。

地点

IEnumerable<SelectListItem> Categories

用于编制可供使用的下级清单。

<%= Html.DropDownListFor(model=>model.NewTask.categoryId, Model.Categories) %>

这将使你成为绝食名单

    private IEnumerable<Category> GetCategories
    {
        get
        {
            List<Category> categories = new List<Category>
                                            {
                                                new Category() {categoryId = 1, categoryName = "test1"},
                                                new Category() {categoryId = 2, categoryName = "category2"}
                                            };
            return categories;
        }
    }

    [AcceptVerbs(HttpVerbs.Get)]
    public ActionResult CreateTask()
    {
        TaskModel taskModel = new TaskModel();
        LoadCategoriesForModel(taskModel);
        return View(taskModel);
    }

    private void LoadCategoriesForModel(TaskModel taskModel)
    {
        taskModel.Categories =
            GetCategories.Select(
                x =>
                new SelectListItem()
                    {Text = x.categoryName, Value = x.categoryId.ToString(CultureInfo.InvariantCulture)});
    }

    public ActionResult CreateTask(TaskModel taskModel)
    {
        if (ModelState.IsValid)
        {
            // do your logic for saving
            return RedirectToAction("Index");
        }
        else
        {
            LoadCategoriesForModel(taskModel);
            return View(taskModel);
        }
    }

    /// <summary>
    /// your model for creation
    /// </summary>
    public class TaskModel
    {
        public Task NewTask { get; set; }
        public IEnumerable<SelectListItem> Categories { get; set; }
    }

    /// <summary>
    /// Task
    /// </summary>
    public class Task
    {
        public int taskId { get; set; }
        public int categoryId { get; set; }
        public string taskName { get; set; }
        public bool isCompleted { get; set; }
        public DateTime creationDate { get; set; }
        public DateTime completionDate { get; set; }
        public string remarks { get; set; }
        public string completionRemarks { get; set; }
    }

    /// <summary>
    /// Category
    /// </summary>
    public class Category
    {
        public int categoryId { get; set; }
        public string categoryName { get; set; }
    }

Answer 2

在《任务评论》中(我更喜欢点名创建TaskViewModel)为选定名单的类别设定了财产。

public IEnumerable<SelectListItem> CategoriesSelectList;

在控制器中,在归还观点之前对该财产进行约束(指出在示范国无效时,也应在邮递中这样做)。

public ViewResult Create()
{
     CreateTaskViewModel  model = new CreateTaskViewModel();
     model.CategoriesSelectList = _repository.AllCategories().Select(x=> new SelectListItem(){ Text = x.CategoryName, Value = x.CategoryId.ToString();}
}

最后,我们认为

Html.DropDownListFor(model => model.CategoryId, Model.CategoriesSelectList)

<><>Edit>:

In your code, _repository.AllCategories() should be replaced by your data access code, that returns object having type IEnumerable<Category>. It actually does not matter which data access technology you use. And do not forget to add the using System.Linq; statement to your controller file, if it s missing.

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