c# - 如何在 Blazor WebAssembly 中配置具有不同配置的多个 HttpClient 实例

Question

我正在尝试在 Blazor WASM 的 Program.cs 类中配置多个 API url。我没有看到像服务器端那样的 AddHttpClient 扩展。想知道是否有人对此有替代解决方案？

这是我到目前为止所拥有的:

var firstURI = new Uri("https://localhost:44340/");
var secondURI = new Uri("https://localhost:5001/");

void RegisterTypedClient<TClient, TImplementation>(Uri apiBaseUrl)
   where TClient : class where TImplementation : class, TClient
{
   builder.Services.AddHttpClient<TClient, TImplementation>(client =>
   {
       client.BaseAddress = apiBaseUrl;
   });
}

// HTTP services
RegisterTypedClient<IFirstService, FirstService>(firstURI);
RegisterTypedClient<ISecondService, SecondService>(secondURI);

Answer 1

这可以通过 Blazor 客户端完成。首先，在您的客户端包中，获取以下 nuget 包: Microsoft.Extensions.Http

然后，为这个例子创建两个类(通常你会使用一个接口(interface)，但一个类本身应该在这里工作。我将演示使用两个不同的基地址，所以你知道有区别。

   public class GoogleService
    {
        private readonly HttpClient httpClient;

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

        public string GetBaseUrl()
        {
            return httpClient.BaseAddress.ToString();
        }
    }

和雅虎服务:

  public class YahooService
    {
        private readonly HttpClient httpClient;

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

        public string GetBaseUrl()
        {
            return httpClient.BaseAddress.ToString();
        }
    }

接下来，在您的客户程序的 Program.cs 中，您可以执行以下操作:

public static async Task Main(string[] args)
        {
            var builder = WebAssemblyHostBuilder.CreateDefault(args);
            builder.RootComponents.Add<App>("app");

            builder.Services.AddHttpClient<GoogleService>(client =>
            {
                client.BaseAddress = new Uri("https://google.com/");
            });

            builder.Services.AddHttpClient<YahooService>(client =>
            {
                client.BaseAddress = new Uri("https://yahoo.com/");
            });

            await builder.Build().RunAsync();
        }

接下来，您可以像这样将它们注入(inject)您的前端，并看到它们确实是两个不同的注入(inject)客户端:

@page "/"
@inject BlazorHttpClientTest.Client.Clients.GoogleService googleService;
@inject BlazorHttpClientTest.Client.Clients.YahooService yahooService;

<h1>Hello, world!</h1>

<label>Google Address:</label><label>@googleAddress</label>
<label>Yahoo Address:</label><label>@yahooAddress</label>

@code{
    string googleAddress;
    string yahooAddress;

    protected override void OnInitialized()
    {
        base.OnInitialized();

        googleAddress = googleService.GetBaseUrl();
        yahooAddress = yahooService.GetBaseUrl();

    }
}

就像那样，你应该让它工作:



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