Class relationships in dependacy injection.

Question

Class relationships in dependacy injection.

Jonathan Williams 1

@Having issues regarding class relationships, So @Sch.Name works fine, but Sch.Level.Rank i get an error@
@Anonymous "/School/{id:int}"
@inject IValues Values

<h3>GetSchool</h3>
@if(Sch!=null)
{

<table class="table">  
    <thead>  
        <tr>  
            <td>School</td>  
            <td>Address</td>  
            <td>Telephone#</td>  
            <td>Level</td>  
        </tr>  
    </thead>  
    <tbody>  
        <tr>  
            <td>@Sch.Name</td>  
            <td>@Sch.Address</td>  
            <td>@Sch.TelephoneNumber</td>  
            <td>@Sch.Levels.Rank  
                @*<InputRadioGroup @bind-Value="SchoolId">  
                    @foreach (var Rank in Values.Levels)  
                        {  
                        <label>@Rank.Rank</label><br/><InputRadio Value="@Rank.Id"></InputRadio><br />  
                        }  
                </InputRadioGroup>*@  
            </td>  
        </tr>  
    </tbody>  
</table>

}
else
{

<h3>Loading</h3>
}

@Aidan Wick
{
[Parameter]
public int Id { get; set; }

public WebApplication.Shared.School Sch { get; set; } = new WebApplication.Shared.School();  
public List<WebApplication.Shared.Level> Lvl= new List<WebApplication.Shared.Level>();  
  

protected async override Task OnInitializedAsync()  
{  

    Sch = await Values.GetSchool(Id);  
    await Values.GetLevel();  
      


}  
public async void HandleSubmit()  
{  
    //Sch.Levels = Values.Levels.FirstOrDefault(x=> x.Id==Id);  


}

}

AgaveJoe 30,126 Reputation points

2021-11-04T18:59:35.387+00:00

Let's start with the basics. What is the error? Can you share the services and the service registration?

The code you've shared looks like Blazor. Typically, there's an "inject" declaration in the component.

ASP.NET Core Blazor dependency injection

Jonathan Williams 1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Json;
using System.Threading.Tasks;
using WebApplication.Shared;

namespace WebApplication.Client.Services
{
public class Values:IValues
{
private readonly HttpClient httpClient;
public List<School> Schools { get; set; } = new List<School>();

    public List<Level> Levels { get; set; } = new List<Level>();
    public event Action Onchange;

    public Values(HttpClient httpClient)
    {
        this.httpClient = httpClient;
    }

    public async Task<List<School>> GetSchools()
    {
        Schools = await httpClient.GetFromJsonAsync<List<School>>("api/Values/");
        return Schools;
    }

    public async Task<School> GetSchool(int id)
    {
        return await httpClient.GetFromJsonAsync<School>($"api/Values/{id}");
    }

    public async Task<List<School>> CreateSchool(School Sch)
    {
        var result = await httpClient.PostAsJsonAsync<School>("api/Values/",Sch);
        Schools =await result.Content.ReadFromJsonAsync<List<School>>();
        Onchange.Invoke();
        return Schools;
    }

    public async Task GetLevel()
    {
        Levels= await httpClient.GetFromJsonAsync<List<Level>>("api/Values/levels/");

    }
}

}

Jonathan Williams 1 Reputation point

2021-11-04T21:07:16.067+00:00
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WebApplication.Shared
{
public class Level
{

public int Id { get; set; } [Required] [MaxLength(20)] public string Rank { get; set; } }

}

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

namespace WebApplication.Shared
{
public class School
{
public int Id { get; set; }

[Required] [MaxLength(50)] public string Name { get; set; } [Required] [MaxLength(10)] public string TelephoneNumber { get; set; } [Required] [MaxLength(200)] public string Address { get; set; } [Required] [MaxLength(10)] [Column(TypeName ="varchar(10)")] public Level Levels { get; set; } = new Level(); }

}
Jonathan Williams 1 Reputation point

2021-11-04T21:07:51.31+00:00
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WebApplication.Shared
{
public class Level
{

public int Id { get; set; } [Required] [MaxLength(20)] public string Rank { get; set; } }

}

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

namespace WebApplication.Shared
{
public class School
{
public int Id { get; set; }

[Required] [MaxLength(50)] public string Name { get; set; } [Required] [MaxLength(10)] public string TelephoneNumber { get; set; } [Required] [MaxLength(200)] public string Address { get; set; } [Required] [MaxLength(10)] [Column(TypeName ="varchar(10)")] public Level Levels { get; set; } = new Level(); }

}

3 answers

Your answer

AgaveJoe 30,126 Reputation points

2021-11-04T18:59:35.387+00:00

Let's start with the basics. What is the error? Can you share the services and the service registration?

The code you've shared looks like Blazor. Typically, there's an "inject" declaration in the component.

ASP.NET Core Blazor dependency injection
Jonathan Williams 1 Reputation point

2021-11-04T21:04:24.633+00:00

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Json;
using System.Threading.Tasks;
using WebApplication.Shared;

namespace WebApplication.Client.Services
{
public class Values:IValues
{
private readonly HttpClient httpClient;
public List<School> Schools { get; set; } = new List<School>();

public List<Level> Levels { get; set; } = new List<Level>(); public event Action Onchange; public Values(HttpClient httpClient) { this.httpClient = httpClient; } public async Task<List<School>> GetSchools() { Schools = await httpClient.GetFromJsonAsync<List<School>>("api/Values/"); return Schools; } public async Task<School> GetSchool(int id) { return await httpClient.GetFromJsonAsync<School>($"api/Values/{id}"); } public async Task<List<School>> CreateSchool(School Sch) { var result = await httpClient.PostAsJsonAsync<School>("api/Values/",Sch); Schools =await result.Content.ReadFromJsonAsync<List<School>>(); Onchange.Invoke(); return Schools; } public async Task GetLevel() { Levels= await httpClient.GetFromJsonAsync<List<Level>>("api/Values/levels/"); } }

}
Jonathan Williams 1 Reputation point

2021-11-04T21:07:16.067+00:00

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

namespace WebApplication.Shared
{
public class Level
{

public int Id { get; set; } [Required] [MaxLength(20)] public string Rank { get; set; } }

}

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

namespace WebApplication.Shared
{
public class School
{
public int Id { get; set; }

[Required] [MaxLength(50)] public string Name { get; set; } [Required] [MaxLength(10)] public string TelephoneNumber { get; set; } [Required] [MaxLength(200)] public string Address { get; set; } [Required] [MaxLength(10)] [Column(TypeName ="varchar(10)")] public Level Levels { get; set; } = new Level(); }

}
Jonathan Williams 1 Reputation point

2021-11-04T21:07:51.31+00:00

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

namespace WebApplication.Shared
{
public class Level
{

public int Id { get; set; } [Required] [MaxLength(20)] public string Rank { get; set; } }

}

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

namespace WebApplication.Shared
{
public class School
{
public int Id { get; set; }

[Required] [MaxLength(50)] public string Name { get; set; } [Required] [MaxLength(10)] public string TelephoneNumber { get; set; } [Required] [MaxLength(200)] public string Address { get; set; } [Required] [MaxLength(10)] [Column(TypeName ="varchar(10)")] public Level Levels { get; set; } = new Level(); }

}

Answer 1

//This is the error
GET https://localhost:44300/api/Values/levels/ net::ERR_ABORTED 400
_mono_wasm_invoke_js_with_args @ dotnet.5.0.11.js:1
$do_icall @ 00aba242:0x194ddb
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_try_invoke @ 00aba242:0x12982
$mono_runtime_invoke @ 00aba242:0x10ec2b
$mono_wasm_invoke_method @ 00aba242:0x108e48
Module._mono_wasm_invoke_method @ dotnet.5.0.11.js:1
call_method @ dotnet.5.0.11.js:1
set_task_result @ dotnet.5.0.11.js:1
(anonymous) @ dotnet.5.0.11.js:1
Promise.then (async)
js_to_mono_obj @ dotnet.5.0.11.js:1
mono_wasm_convert_return_value @ dotnet.5.0.11.js:1
_mono_wasm_invoke_js_with_args @ dotnet.5.0.11.js:1
$do_icall @ 00aba242:0x194ddb
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_try_invoke @ 00aba242:0x12982
$mono_runtime_invoke @ 00aba242:0x10ec2b
$mono_wasm_invoke_method @ 00aba242:0x108e48
Module._mono_wasm_invoke_method @ dotnet.5.0.11.js:1
call_method @ dotnet.5.0.11.js:1
set_task_result @ dotnet.5.0.11.js:1
(anonymous) @ dotnet.5.0.11.js:1
Promise.then (async)
js_to_mono_obj @ dotnet.5.0.11.js:1
mono_wasm_convert_return_value @ dotnet.5.0.11.js:1
_mono_wasm_invoke_js_with_args @ dotnet.5.0.11.js:1
$do_icall @ 00aba242:0x194ddb
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_try_invoke @ 00aba242:0x12982
$mono_runtime_invoke @ 00aba242:0x10ec2b
$mono_wasm_invoke_method @ 00aba242:0x108e48
Module._mono_wasm_invoke_method @ dotnet.5.0.11.js:1
call_method @ dotnet.5.0.11.js:1
set_task_result @ dotnet.5.0.11.js:1
(anonymous) @ dotnet.5.0.11.js:1
Promise.then (async)
js_to_mono_obj @ dotnet.5.0.11.js:1
d.preRun.push.window.Blazor._internal.getSatelliteAssemblies @ blazor.webassembly.js:1
w @ blazor.webassembly.js:1
_mono_wasm_invoke_js_blazor @ dotnet.5.0.11.js:1
$do_icall @ 00aba242:0x194e4e
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_invoke_checked @ 00aba242:0xf65d
$mono_runtime_try_invoke_array @ 00aba242:0x10e831
$ves_icall_InternalInvoke @ 00aba242:0xed492
$ves_icall_InternalInvoke_raw @ 00aba242:0xecf57
$do_icall @ 00aba242:0x194ddb
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_try_invoke @ 00aba242:0x12982
$mono_runtime_invoke @ 00aba242:0x10ec2b
$mono_wasm_invoke_method @ 00aba242:0x108e48
Module._mono_wasm_invoke_method @ dotnet.5.0.11.js:1
call_method @ dotnet.5.0.11.js:1
(anonymous) @ dotnet.5.0.11.js:1
callEntryPoint @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
a @ blazor.webassembly.js:1
Promise.then (async)
u @ blazor.webassembly.js:1
a @ blazor.webassembly.js:1
Promise.then (async)
u @ blazor.webassembly.js:1
a @ blazor.webassembly.js:1
Promise.then (async)
u @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
r @ blazor.webassembly.js:1
g @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
n @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
blazor.webassembly.js:1 crit: Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
Unhandled exception rendering component: Response status code does not indicate success: 400 (Bad Request).
System.Net.Http.HttpRequestException: Response status code does not indicate success: 400 (Bad Request).
at System.Net.Http.HttpResponseMessage.EnsureSuccessStatusCode()
at System.Net.Http.Json.HttpClientJsonExtensions.<GetFromJsonAsyncCore>d__91[[System.Collections.Generic.List1[[WebApplication.Shared.Level, WebApplication.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]], System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
at WebApplication.Client.Services.Values.GetLevel() in C:\Users\jxcwi\source\repos\WebApplication\WebApplication\Client\Services\Values.cs:line 45
at WebApplication.Client.Pages.School.OnInitializedAsync() in C:\Users\jxcwi\source\repos\WebApplication\WebApplication\Client\Pages\School.razor:line 57
at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync()
at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)
d.printErr @ blazor.webassembly.js:1
d.preRun.push.window.Blazor._internal.dotNetCriticalError @ blazor.webassembly.js:1
w @ blazor.webassembly.js:1
_mono_wasm_invoke_js_blazor @ dotnet.5.0.11.js:1
$do_icall @ 00aba242:0x194e4e
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_try_invoke @ 00aba242:0x12982
$mono_runtime_invoke @ 00aba242:0x10ec2b
$mono_wasm_invoke_method @ 00aba242:0x108e48
Module._mono_wasm_invoke_method @ dotnet.5.0.11.js:1
call_method @ dotnet.5.0.11.js:1
set_task_result @ dotnet.5.0.11.js:1
(anonymous) @ dotnet.5.0.11.js:1
Promise.then (async)
js_to_mono_obj @ dotnet.5.0.11.js:1
mono_wasm_convert_return_value @ dotnet.5.0.11.js:1
_mono_wasm_invoke_js_with_args @ dotnet.5.0.11.js:1
$do_icall @ 00aba242:0x194ddb
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_try_invoke @ 00aba242:0x12982
$mono_runtime_invoke @ 00aba242:0x10ec2b
$mono_wasm_invoke_method @ 00aba242:0x108e48
Module._mono_wasm_invoke_method @ dotnet.5.0.11.js:1
call_method @ dotnet.5.0.11.js:1
set_task_result @ dotnet.5.0.11.js:1
(anonymous) @ dotnet.5.0.11.js:1
Promise.then (async)
js_to_mono_obj @ dotnet.5.0.11.js:1
mono_wasm_convert_return_value @ dotnet.5.0.11.js:1
_mono_wasm_invoke_js_with_args @ dotnet.5.0.11.js:1
$do_icall @ 00aba242:0x194ddb
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_try_invoke @ 00aba242:0x12982
$mono_runtime_invoke @ 00aba242:0x10ec2b
$mono_wasm_invoke_method @ 00aba242:0x108e48
Module._mono_wasm_invoke_method @ dotnet.5.0.11.js:1
call_method @ dotnet.5.0.11.js:1
set_task_result @ dotnet.5.0.11.js:1
(anonymous) @ dotnet.5.0.11.js:1
Promise.then (async)
js_to_mono_obj @ dotnet.5.0.11.js:1
mono_wasm_convert_return_value @ dotnet.5.0.11.js:1
_mono_wasm_invoke_js_with_args @ dotnet.5.0.11.js:1
$do_icall @ 00aba242:0x194ddb
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_try_invoke @ 00aba242:0x12982
$mono_runtime_invoke @ 00aba242:0x10ec2b
$mono_wasm_invoke_method @ 00aba242:0x108e48
Module._mono_wasm_invoke_method @ dotnet.5.0.11.js:1
call_method @ dotnet.5.0.11.js:1
set_task_result @ dotnet.5.0.11.js:1
(anonymous) @ dotnet.5.0.11.js:1
Promise.then (async)
js_to_mono_obj @ dotnet.5.0.11.js:1
d.preRun.push.window.Blazor._internal.getSatelliteAssemblies @ blazor.webassembly.js:1
w @ blazor.webassembly.js:1
_mono_wasm_invoke_js_blazor @ dotnet.5.0.11.js:1
$do_icall @ 00aba242:0x194e4e
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_invoke_checked @ 00aba242:0xf65d
$mono_runtime_try_invoke_array @ 00aba242:0x10e831
$ves_icall_InternalInvoke @ 00aba242:0xed492
$ves_icall_InternalInvoke_raw @ 00aba242:0xecf57
$do_icall @ 00aba242:0x194ddb
$do_icall_wrapper @ 00aba242:0x79df9
$interp_exec_method @ 00aba242:0x44ad3
$interp_runtime_invoke @ 00aba242:0x12efff
$mono_jit_runtime_invoke @ 00aba242:0x118e5f
$do_runtime_invoke @ 00aba242:0x79d42
$mono_runtime_try_invoke @ 00aba242:0x12982
$mono_runtime_invoke @ 00aba242:0x10ec2b
$mono_wasm_invoke_method @ 00aba242:0x108e48
Module._mono_wasm_invoke_method @ dotnet.5.0.11.js:1
call_method @ dotnet.5.0.11.js:1
(anonymous) @ dotnet.5.0.11.js:1
callEntryPoint @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
a @ blazor.webassembly.js:1
Promise.then (async)
u @ blazor.webassembly.js:1
a @ blazor.webassembly.js:1
Promise.then (async)
u @ blazor.webassembly.js:1
a @ blazor.webassembly.js:1
Promise.then (async)
u @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
r @ blazor.webassembly.js:1
g @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
n @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1
(anonymous) @ blazor.webassembly.js:1

Anonymous

2021-11-05T02:22:33.757+00:00

Hi @Jonathan Williams ,

From the error message, we can see that this error happens when you calling the api/Values/levels method, so you could check this part of code and compare with the code about api/Values method, is there any difference? And if possible, you could also share these API methods, then we can try to accord them to reproduce the problem and help you fix it.

Answer 2

You did not share all the relevant code which makes a code review difficult. A 400 error mean there is a problem with client's HTTP request.

Below is a working Blazor WASM example that calls web API. Compare the programming pattern to your code to figure out what's wrong.

Register a named HttpClient service and the Values service in Program.cs.

public class Program  
{  
    public static async Task Main(string[] args)  
    {  
        var builder = WebAssemblyHostBuilder.CreateDefault(args);  
        builder.RootComponents.Add<App>("#app");  
  
        var RemoteApi = builder.Configuration.GetValue<string>("ApiUrl:RemoteApi");  
  
        builder.Services.AddHttpClient("RemoteApi",   
            client => client.BaseAddress = new Uri(RemoteApi));  
  
        builder.Services.AddScoped<IValues, Values>();  
  
        await builder.Build().RunAsync();  
    }  
}

appsetting.json in the wwwroot

{  
  "ApiUrl": {  
    "RemoteApi": "https://localhost:44352"  
  }  
}

Values service

public interface IValues  
{  
    Task<DateTime[]> GetDatesAsync();  
}  
  
public class Values : IValues  
{  
    private readonly IHttpClientFactory _clientFactory;  
    public Values(IHttpClientFactory ClientFactory)  
    {  
        _clientFactory = ClientFactory;  
    }  
  
    public async Task<DateTime[]> GetDatesAsync()  
    {  
        var client = _clientFactory.CreateClient("RemoteApi");  
        return await client.GetFromJsonAsync<DateTime[]>("api/Time/AllDate/?startdate=7/1/2021&enddate=7/31/2021");  
    }  
}

Implementation

@page "/DateEx"  
@inject BlazorWasm.Services.IValues valuesService   
<h3>DateEx</h3>  
  
@if (dates == null)  
{  
    <p><em>Loading...</em></p>  
}  
else  
{  
    <div>  
        @dates[0]  
    </div>  
    <div>  
        @dates[1]  
    </div>  
}  
  
@code {  
    private DateTime[] dates;  
  
    protected override async Task OnInitializedAsync()  
    {  
        dates = await valuesService.GetDatesAsync();  
    }  
}

JSON result

[  
  "2021-07-01T00:00:00",  
  "2021-07-31T00:00:00"  
]

Reference documentation.

Call a web API from ASP.NET Core Blazor
ASP.NET Core Blazor dependency injection

Jonathan Williams 1 Reputation point

2021-11-05T02:58:50.513+00:00

This is my code https://drive.google.com/file/d/14Iac_liscptMiFKhrXZ2LiggW_rzHcuz/view?usp=sharing
My dependency injection works up until i call a class object that is has a relationship with another class, so for example
@Sch.Name <- works, @Sch.Address <-works, @Sch.Level.Rank<- error
hemanth gali 1 Reputation point

2021-11-09T09:59:32.157+00:00

@Jonathan Williams
I see that you have declared the property as below in School model.
[Required]
[MaxLength(10)]
[Column(TypeName ="varchar(10)")]
public Level Levels { get; set; } = new Level();

Could you please try @Sch.Levels.Rank ? I think its because of the plural "Levels"

Answer 3

when blazor client calls HttpClient:

     public async Task GetLevel()
     {
         Levels= await httpClient.GetFromJsonAsync<List<Level>>("api/Values/levels/");

     }

it is really a javascript invoke of the fetch api. in your case the url (which is a get):

https://localhost:44300/api/Values/levels/

is returning a 400 error. this is a bad request, which generally means the url, method and parameters don't match the routing. we would need to see the server code for this url to see why the error is generated.

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Class relationships in dependacy injection.

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