Blazor - 从数据库获取内部服务器错误

Question

我有一个 blazor Web 应用程序（自动），可以从客户端的数据库中获取项目。 我已经创建了服务和控制器来获取所有有效的项目，但是当我尝试搜索特定项目时，它会中断，并且出现此错误：

crit: Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
      Unhandled exception rendering component: Response status code does not indicate success: 500 (Internal Server Error).
System.Net.Http.HttpRequestException: Response status code does not indicate success: 500 (Internal Server Error).
   at System.Net.Http.HttpResponseMessage.EnsureSuccessStatusCode()
   at System.Net.Http.Json.HttpClientJsonExtensions.<<FromJsonAsyncCore>g__Core|12_0>d`2[[System.Collections.Generic.List`1[[Design_A_Bear.Models.Item, Design_A_Bear.Models, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]], System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Text.Json.JsonSerializerOptions, System.Text.Json, Version=8.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51]].MoveNext()
   at Design_A_Bear.Services.ClientItemService.GetItemsByCategory(String category) in C:\Users\User\source\repos\Design_A_Bear_2.0\Design_A_Bear.Services\ClientItemService.cs:line 56
   at Design_A_Bear.Client.Pages.Items.Browse.OnInitializedAsync() in C:\Users\User\source\repos\Design_A_Bear_2.0\Design_A_Bear\Design_A_Bear.Client\Pages\Items\Browse.razor:line 49
   at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync()
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)

相关代码如下：

IItemService.CS:

Task<List<Item>> GetItemsByCategory(string category);

ItemService.CS:

public async Task<List<Item>> GetItemsByCategory(string category)
{
    List<Item>items = await _db.Items.Where(item => item.Category == category).ToListAsync();
    return items;
}

ClientItemService.cs

public async Task<List<Item>> GetItemsByCategory(string category)
{
    var result = await  _httpClient.GetFromJsonAsync<List<Item>>($"/api/Item/{category}");
    return result;
}

ItemController.cs

[HttpGet("{category}")]
public async Task<ActionResult> GetItemsByCategory(string category)
{
    var items = await _itemServices.GetItemsByCategory(category);
    return Ok(items);
}

更新： 这是我收到的错误：

An unhandled exception occurred while processing the request.
AmbiguousMatchException: The request matched multiple endpoints. Matches:

Design_A_Bear.Controllers.ItemController.GetItemsByCategory (Design_A_Bear)
Design_A_Bear.Controllers.ItemController.GetItemById (Design_A_Bear)

这是因为我有两个接受参数的 get 函数。我怎样才能选择我想要的呢？

        public async Task<List<Item>> GetItemsByCategory(string category)
        {
            var result = await  _httpClient.GetFromJsonAsync<List<Item>>($"/api/Item/{category}");
            return result;
        }

        public async Task<Item> GetItemById(int id)
        {
            var result = await _httpClient.GetFromJsonAsync<Item>($"/api/Item/{id}");
            return result;
        }

Answer 1

为了区分同一控制器上的两个 GET 端点，您需要为每个端点添加路由。

对于第一个端点

[Route("category/{category}")]

对于第二个端点

[Route("items/{id}")]

控制器方法上方的这些内容应该可以解决具有两个 GET 端点的问题。

https://learn.microsoft.com/en-us/aspnet/web-api/overview/web-api-routing-and-actions/attribute-routing-in-web-api-2