Question

我已经使用Kendo Grid显示数据。似乎数据正确传递，因为当我在运行时跟踪代码时，我看到有一些数据在结果中但是Kendo Grid无法显示数据。我该如何解决这个问题？

编辑说明：

我找到了问题原因，但我无法解决。 如果我在QueryBuilder（）方法中的ViewModel中删除此行，

Tags = article.ArticleTags.Where（c =＆gt; c.ArticleId == article.Id）.Select（b =＆gt; b.Tag）.Distinct（）。ToList（）

网格显示数据，但我需要标记的值。为什么这行代码导致了问题？

标记模型：

public class Tag : Entity, ITag
    {
        public Tag()
        {
        }
        public virtual string Title { get; set; }
        public virtual string Description { get; set; }
        public virtual bool? IsActive { get; set; }
        [Range(1, 4)]
        public virtual int Size { get; set; }

        public virtual ISet<ArticleTag> ArticleTags { get; set; }
        public virtual ISet<ProjectTag> ProjectTags { get; set; }
    }

我的网格：

@using Jahan.Blog.Web.Mvc.HtmlHelpers
@using Kendo.Mvc.UI
@using Kendo.Mvc.UI.Fluent
@model IEnumerable<Jahan.Blog.ViewModel.ArticleViewModel>
@{
    ViewBag.Title = "Index";
}

<h2>Index</h2>

<p>
    @Html.ActionLink("Create New", "Create")
</p>
<div style="width: 100%;">
    @(Html.Kendo().Grid<Jahan.Blog.ViewModel.ArticleViewModel>()
          .Name("ArticleAdmin").Navigatable()
          .Resizable(c => c.Columns(true))
          .HtmlAttributes(new { @class = "cursorLink", @style = "width: 1000px;height:auto;overflow: scroll;" })
          .Columns(columns =>
          {
              columns.Bound(p => p.Id).Width(100);
              columns.Bound(p => p.Title).Width(200);
              columns.Command(command => command.Destroy()).Width(170);
          })
          .ToolBar(toolbar =>
          {
              toolbar.Create();
              toolbar.Save();
          })
          .Editable(editable => editable.Mode(GridEditMode.InCell))
          .Pageable()
          .Navigatable()
          .Sortable()
          .Scrollable()
          .DataSource(dataSource => dataSource
              .Ajax()
              .Batch(true)
              .PageSize(10)
              .ServerOperation(false)
              .Events(events => events.Error("error_handler"))
              .Model(model => model.Id(p => p.Id))
              .Create("Editing_Create", "ArticleAdmin")
              .Read("Editing_Read", "ArticleAdmin")
              .Update("Editing_Update", "ArticleAdmin")
              .Destroy("Editing_Destroy", "ArticleAdmin")
          ))
</div>

在我的控制器中：

public ActionResult Index([DataSourceRequest] DataSourceRequest request)
        {
            List<ArticleViewModel> instance = new ArticleViewModel().FindByCriteria().ToList();
            return View(instance); // There are some data. instance.count = 2
        }

        public ActionResult Editing_Read([DataSourceRequest] DataSourceRequest request)
        {
            List<ArticleViewModel> instance = new ArticleViewModel().FindByCriteria().ToList();
            DataSourceResult dsRequest = instance.ToDataSourceResult(request); // There are some data.
            return Json(dsRequest, JsonRequestBehavior.AllowGet);
        }

我的ViewModel：

public class ArticleViewModel : IArticle, IDateTracking
    {
        public ArticleViewModel()
        {

        }
        public int? UserId { get; set; }

        public string Title { get; set; }

        public string Summary { get; set; }

        public string Description { get; set; }

        public decimal? RateCounter { get; set; }

        public int? LikeCounter { get; set; }

        public bool IsActive { get; set; }

        public bool IsActiveNewComment { get; set; }

        public IList<Comment> Comments { get; set; }

        public ISet<Rating> Ratings { get; set; }

        public IList<AttachmentFile> AttachmentFiles { get; set; }

        public ISet<ArticleTag> ArticleTags { get; set; }

        public ISet<ArticleLike> ArticleLikes { get; set; }

        public int Id { get; set; }

        public DateTime? CreatedDate { get; set; }

        public DateTime? ModifiedDate { get; set; }

        [UIHint("_TagsOfArticle")]
        public virtual IList<Tag> Tags { get; set; }
        public virtual int NumberOfComments { get; set; }
        public virtual User User { get; set; }

        private IQueryable<ArticleViewModel> QueryBuilder()
        {
            ArticleRepository repository = new ArticleRepository();
            IQueryable<ArticleViewModel> query = repository.FindAll().Select(article => new ArticleViewModel
            {
                Id = article.Id,
                AttachmentFiles = article.AttachmentFiles.Where(a => a.ArticleId == article.Id).Distinct().ToList(),
                Comments = article.Comments.Where(c => c.ArticleId == article.Id).ToList(),
                CreatedDate = article.CreatedDate,
                //Description = article.Description,
                IsActive = article.IsActive,
                IsActiveNewComment = article.IsActiveNewComment,
                LikeCounter = article.LikeCounter,
                ModifiedDate = article.ModifiedDate,
                NumberOfComments = article.Comments.Count(c => c.ArticleId == article.Id),
                RateCounter = article.RateCounter,
                //Summary = article.Summary,
                Tags = article.ArticleTags.Where(c => c.ArticleId == article.Id).Select(b => b.Tag).Distinct().ToList(),
                Title = article.Title,
                UserId = article.UserId
            });
            return query;
        }

        public virtual IQueryable<ArticleViewModel> QueryBuilderByCriteria(Expression<Func<ArticleViewModel, bool>> predicate = null, params Expression<Func<ArticleViewModel, object>>[] includeProperties)
        {
            IQueryable<ArticleViewModel> items = QueryBuilder();
            if (includeProperties != null)
            {
                foreach (Expression<Func<ArticleViewModel, object>> includeProperty in includeProperties)
                {
                    items = items.Include(includeProperty);
                }
            }
            if (predicate != null)
                return items.Where(predicate);
            return items;
        }

        public virtual IEnumerable<ArticleViewModel> FindByCriteria(Expression<Func<ArticleViewModel, bool>> predicate = null, params Expression<Func<ArticleViewModel, object>>[] includeProperties)
        {
            List<ArticleViewModel> result = QueryBuilderByCriteria(predicate, includeProperties).ToList();
            return result;
        }

        public virtual ArticleViewModel FindByArticleId(int articleId)
        {
            ArticleViewModel result = QueryBuilder().FirstOrDefault(a => a.Id == articleId);
            return result;
        }
    }

Answer 1

为了解决这个问题，我进行了一些改动。 1）我没有使用Tag模型，而是使用了TagViewModel。我已经找到了Tag模型，本身就是问题的原因！我不知道为什么会这样。然后我决定创建一个简化Tag类的TagViewModel。

public class TagGridViewModel
    {
        public virtual int Id { get; set; }

        public virtual string Title { get; set; }

        public virtual string Description { get; set; }

        public virtual bool? IsActive { get; set; }

        public virtual int Size { get; set; }

        public static List<TagGridViewModel> GetByArticleId(int articleId)
        {
            List<TagGridViewModel> tags = new List<TagGridViewModel>();
            List<Tag> tagsPerArticle = ArticleRepository.Instance.GetTagsByArticleId(articleId);
            foreach (var tag in tagsPerArticle)
            {
                tags.Add(new TagGridViewModel
                {
                    Id = tag.Id,
                    IsActive = tag.IsActive,
                    Description = tag.Description,
                    Title = tag.Title,
                    Size = tag.Size
                });
            }
            return tags;
        }
    }

在ArticleViewModel中：

    public List<TagGridViewModel> Tags { get; set; }

在FindByCriteria方法中：

public virtual IEnumerable<ArticleViewModel> FindByCriteria(Expression<Func<ArticleViewModel, bool>> predicate = null, params Expression<Func<ArticleViewModel, object>>[] includeProperties)
        {
            List<ArticleViewModel> result = new List<ArticleViewModel>();
            var query = QueryBuilderByCriteria(predicate, includeProperties);
            foreach (var articleViewModel in query)
            {
                articleViewModel.Tags = TagGridViewModel.GetByArticleId(articleViewModel.Id); 
                articleViewModel.Owner = AppUserStore.Instance.FindByIdAsync(int.Parse(articleViewModel.UserId.ToString())).Result.UserName;
                result.Add(articleViewModel);
            }
            return result;
        }

完成这些更改后，Grid会显示数据。

数据未在Kendo MVC Grid中显示

1 个答案: