是否有 .cs 文件等同于 .razor 文件的 @inject HttpClient Http

Question

在我使用的 .razor 文件中

@inject HttpClient Http

访问 HTTPClient。

有没有办法在 .cs 文件中做同样的事情，还是我必须将它作为参数传递？

更新

我以为我有，但我没有。

使用语句

using System.Net.Http;
using Microsoft.AspNetCore.Components;
using System.Net.Http.Json;

定义为class参数

    [Inject]
    protected HttpClient Http {get;set;}

在我的通话任务中

    await  Http.GetFromJsonAsync<SharedGLAccount[]>($"api/{ST_comp}/GLAccounts")

出现以下错误

Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
      Unhandled exception rendering component: Value cannot be null. (Parameter 'client')

Answer 1

我建议您为此使用 IHttpClientFactory。查看 this 文档，其中解释了使用它的好处并复制如下：

Provides a central location for naming and configuring logical HttpClient instances. For example, a client named github could be registered and configured to access GitHub. A default client can be registered for general access.

Codifies the concept of outgoing middleware via delegating handlers in HttpClient. Provides extensions for Polly-based middleware to take advantage of delegating handlers in HttpClient.

Manages the pooling and lifetime of underlying HttpClientMessageHandler instances. Automatic management avoids common DNS (Domain Name System) problems that occur when manually managing HttpClient lifetimes.

Adds a configurable logging experience (via ILogger) for all requests sent through clients created by the factory.

一个用法示例是：

在 startup.cs 文件中：

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddHttpClient(); // <- add this

您可以在服务或存储库中使用它进行注入 class:

public class BasicService : IBasicService
{
    private readonly IHttpClientFactory _httpClientFactory;

    public BasicUsageModel(IHttpClientFactory httpClientFactory) // <- inject here
    {
        _httpClientFactory = httpClientFactory;
    }

或者如果它的剃须刀页面代码在后面：

[Inject] public IHttpClientFactory HttpClientFactory { get; set; }

或者这个，如果它的剃刀页面：

@inject IHttpClientFactory HttpClientFactory

并像这样使用它：

var httpClient = _clientFactory.CreateClient(); // <- create HTTP client

是否有 .cs 文件等同于 .razor 文件的 @inject HttpClient Http

Is there .cs file equivalent for .razor file's @inject HttpClient Http

c#

razor

webassembly

blazor