Razor 页面中未显示多个相关表的数据

Posted 2023-03-27

【中文标题】Razor 页面中未显示多个相关表的数据

【英文标题】：Data of Multiple related tables not shown in Razor page

【发布时间】：2020-01-02 08:04:43

【问题描述】：

我正在使用 .net 核心 2.2。当我运行以下输出时，FacultyInterestItem 列表中显示了 Faculty 或 Keywords 表数据缺失。虽然 Faculties 和 Keywords 类与 FacltyInterestItems 相关联

以下是剃须刀页面

<tbody>
    @foreach (var item in Model.FacultyInterestItems)
    
        <tr>
 <td>     @html.DisplayFor(modelItem => item.Id)           
        </td>                
 <td>
                @Html.DisplayFor(modelItem => item.Faculty.FacultyId)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Keyword.Name)
            </td>
            <td>
                <a asp-page="./Edit" asp-route-id="@item.Id">Edit</a> |
                <a asp-page="./Details" asp-route-id="@item.Id">Details</a> |
                <a asp-page="./Delete" asp-route-id="@item.Id">Delete</a>
            </td>
        </tr>
    
</tbody>

Razor 页面的 cs 文件具有 OnGetAsync() 方法，它连接并从 WebAPI 获取数据。

public async Task OnGetAsync()

    List<FacultyInterestItems> facultyInterestItem = new List<FacultyInterestItems>();
    HttpClient client = _api.Initial();
    HttpResponseMessage res = await client.GetAsync("api/FacultyInterestItems");
    if (res.IsSuccessStatusCode)
    
        var result = res.Content.ReadAsStringAsync().Result;
        facultyInterestItem = JsonConvert.DeserializeObject<List<FacultyInterestItems>>(result);
    
    List<Faculties> listOfFaculty = new List<Faculties>();
    res = await client.GetAsync("api/Faculties");
    if (res.IsSuccessStatusCode)
    
        var result = res.Content.ReadAsStringAsync().Result;
        listOfFaculty = JsonConvert.DeserializeObject<List<Faculties>>(result);
    
    List<Keywords> listOfKeywords = new List<Keywords>();
    res = await client.GetAsync("api/Keywords");
    if (res.IsSuccessStatusCode)
    
        var result = res.Content.ReadAsStringAsync().Result;
        listOfKeywords = JsonConvert.DeserializeObject<List<Keywords>>(result);
    
    FacultyInterestItems = facultyInterestItem;
    Keywords = listOfKeywords;
    Faculties = listOfFaculty;

razor page cs文件中的OnGetAscyn()程序，从API获取数据。这是连接到数据库并获取数据的 API 控制器中的 get 方法。

[HttpGet]
public async Task<ActionResult<IEnumerable<FacultyInterestItems>>> GetFacultyInterestItems()

    return await _context.FacultyInterestItems.ToListAsync();

这是模型：

学院表

public partial class Faculties

    public Faculties()
    
        FacultyInterestItems = new HashSet<FacultyInterestItems>();
        SuggestedKeywords = new HashSet<SuggestedKeywords>();
    

    public long Id  get; set; 
    public string FacultyId  get; set; 
    public DateTime? UpdateDate  get; set; 
    public DateTime? InsertDate  get; set; 

    public virtual ICollection<FacultyInterestItems> FacultyInterestItems  get; set; 
    public virtual ICollection<SuggestedKeywords> SuggestedKeywords  get; set; 

FacultyInterestItems 表：

public partial class FacultyInterestItems

    public long Id  get; set; 
    public long? FacultyId  get; set; 
    public int? KeywordId  get; set; 
    public DateTime InsertDate  get; set; 
    public DateTime UpdateDate  get; set; 

    public virtual Faculties Faculty  get; set; 
    public virtual Keywords Keyword  get; set; 

关键字表：

public partial class Keywords

    public Keywords()
    
        FacultyInterestItems = new HashSet<FacultyInterestItems>();
    

    public int Id  get; set; 
    public string Name  get; set; 
    public DateTime InsertDate  get; set; 
    public DateTime UpdateDate  get; set; 
    public int? DepartmentId  get; set; 

    public virtual Departments Department  get; set; 
    public virtual ICollection<FacultyInterestItems> FacultyInterestItems  get; set; 

没有从数据库中获取教师和关键字的数据。请告诉我解决方案

【参考方案1】：

尝试调用Include方法

 _context.FacultyInterestItems.Include(x => x.Faculty).Include(x => x.Keyword).ToListAsync()

【讨论】：

我这样做了它在这条线上给出了错误 FacultyInterestItem = JsonConvert.DeserializeObject>(result); JsonSerializationException：反序列化数组时意外结束。路径“[0].faculty.facultyInterestItems”，第 1 行，位置 207。

解决了！谢谢马丁，问题出在我生成的模型上，我在它工作时删除了它 public virtual ICollection FacultyInterestItems get;放; 在 Faculties.cs 中