未处理的异常 Json 在 Blazor 上显示数据

Posted 2023-04-12

【中文标题】未处理的异常 Json 在 Blazor 上显示数据

【英文标题】：Unhandled exception Json Display data on Blazor

【发布时间】：2021-10-22 00:10:34

【问题描述】：

我正在尝试在 blazor 上显示添加到我的项目中的 Json 文件，但出现以下错误：

   Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
      Unhandled exception rendering component: The JSON value could not be converted to Blazor_fresh_project.Shared.Job[]. Path: $ | LineNumber: 0 | BytePositionInLine: 1.
System.Text.Json.JsonException: The JSON value could not be converted to Blazor_fresh_project.Shared.Job[]. Path: $ | LineNumber: 0 | BytePositionInLine: 1.
   at System.Text.Json.ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(Type propertyType)
   at System.Text.Json.Serialization.Converters.IEnumerableDefaultConverter`2[[Blazor_fresh_project.Shared.Job[], Blazor_fresh_project.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Blazor_fresh_project.Shared.Job, Blazor_fresh_project.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].OnTryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, Job[]& value)
   at System.Text.Json.Serialization.JsonConverter`1[[Blazor_fresh_project.Shared.Job[], Blazor_fresh_project.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].TryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, Job[]& value)
   at System.Text.Json.Serialization.JsonConverter`1[[Blazor_fresh_project.Shared.Job[], Blazor_fresh_project.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].ReadCore(Utf8JsonReader& reader, JsonSerializerOptions options, ReadStack& state)
   at System.Text.Json.JsonSerializer.ReadCore[Job[]](JsonConverter jsonConverter, Utf8JsonReader& reader, JsonSerializerOptions options, ReadStack& state)
   at System.Text.Json.JsonSerializer.ReadCore[Job[]](JsonReaderState& readerState, Boolean isFinalBlock, ReadOnlySpan`1 buffer, JsonSerializerOptions options, ReadStack& state, JsonConverter converterBase)
   at System.Text.Json.JsonSerializer.<ReadAsync>d__20`1[[Blazor_fresh_project.Shared.Job[], Blazor_fresh_project.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].MoveNext()
   at System.Net.Http.Json.HttpContentJsonExtensions.<ReadFromJsonAsyncCore>d__3`1[[Blazor_fresh_project.Shared.Job[], Blazor_fresh_project.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].MoveNext()
   at System.Net.Http.Json.HttpClientJsonExtensions.<GetFromJsonAsyncCore>d__9`1[[Blazor_fresh_project.Shared.Job[], Blazor_fresh_project.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].MoveNext()
   at Blazor_fresh_project.Client.Pages.Sugestionpool.OnInitializedAsync() in C:\Users\VFlor\source\repos\Blazor_fresh_project\Blazor_fresh_project\Client\Pages\Sugestionpool.razor:line 40
   at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync()
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)

这是我的脚本：

Razor 页面“Sugestionpool.razor”

@using Blazor_fresh_project.Shared
@page "/AskIt"

@inject HttpClient Http;



<h1>Sugesstion pool</h1>
@if(Jobs==null)

    <p><em>Loading....</em></p>

else


<table class="table">
    <thead>
        <tr>
            <th scope="col">#</th>
            <th scope="col">Name of job</th>
            <th scope="col">State of job</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            @foreach (Job job in Jobs)
            
                <td>@job.Key</td>
                <td>@job.Value</td>
            
        </tr>
    </tbody>
</table>

@code 

    private List<Job> Jobs;
    protected override async Task OnInitializedAsync()
    
        Jobs = await Http.GetFromJsonAsync<List<Job>>("sample-data/job.json");
    

类 Job.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


namespace Blazor_fresh_project.Shared

    public class Job
    
        [Required]
        public string Value  get; set; 
        [Required]
        public string Key  get; set; 
    

Json 文件“job.json”：

  "ArrayOfDataManager": 
    "-xmlns:xsd": "http://www.w3.org/2001/XMLSchema",
    "-xmlns:xsi": "http://www.w3.org/2001/XMLSchema-instance",

      
        "Key": "Are you alive?",
        "Value": "true"
      ,
      
        "Key": "Is it working?",
        "Value": "true"
      ,
      
        "Key": "Working ?",
        "Value": "false"
      ,
      
        "Key": "can you tell me what are yu doing",
        "Value": "true"
      ,
      
        "Key": "can you tell me what ...?",
        "Value": "false"
      

  

我试着做这个：

作业作为作业 [] 而不是列表。 将 Job.cs 更改为布尔值。 在我的 Json 文件中删除 4 第一行并在数据周围添加 []。

有什么建议吗？

【参考方案1】：

这真的是你的 JSON。数组（或列表）应如下所示

[
  
    "Key": "Are you alive?",
    "Value": "true"
  ,


  
    "Key": "can you tell me what ...?",
    "Value": "false"
  
]

【讨论】：

其实是一个xml文件一开始就转成json了，我试过这个解决方案，其实还不错，但是要应用更改，我不得不重置chrome，谢谢回复和帮助;)