在自定义客户端中使用来自IHttpClientFactory的命名IHttpClientFactory

Question

我知道我会因为问这个问题而被钉死，这个问题已经问过无数次了，我向你保证，我已经看过其中的大部分问题/答案，但我还是有点被困住了。

这是一个支持.NET Core6API的ASP.NET标准2.0类库。

在我的Program.cs中，我创建了一个名为HttpClient的HttpClient：

builder.Services.AddHttpClient("XYZ_Api_Client", config =>
{
    var url = "https://example.com/api";
    config.BaseAddress = new Uri(url);
});

我有一个使用这个HttpClient的定制客户机，我在Program.cs中创建了一个单例MyCustomClient，这样我的存储库就可以使用它了。代码在下面。这就是我陷入困境的地方，因为我不知道如何将我命名的HttpClient传递到MyCustomClient。

builder.Services.AddSingleton(new MyCustomClient(???)); // I think I need to pass the HttpClient to my CustomClient here but not sure how

我的CustomClient需要使用这个名为XYZ_Api_Client的HttpClient来完成它的工作：

public class MyCustomClient
{
   private readonly HttpClient _client;
   public MyCustomClient(HttpClient client)
   {
       _client = client;
   }

   public async Task<bool> DoSomething()
   {
      var result = await _client.GetAsync();
      return result;
   }
}

因此，我不知道如何将这个名为HttpClient的名称传递到Program.cs中的MyCustomClient中。

Answer 1

可以在类中直接注入IHttpClientFactory，然后将命名的HttpClient分配给属性。

注册工厂和自定义客户端：

builder.Services.AddHttpClient("XYZ_Api_Client", config =>
{
    var url = "https://example.com/api";
    config.BaseAddress = new Uri(url);
});

// no need to pass anything, the previous line registered IHttpClientFactory in the container
builder.Services.AddSingleton<MyCustomClient>();

然后在你们班：

public class MyCustomClient
{
   private readonly HttpClient _client;
   public MyCustomClient(IHttpClientFactory factory)
   {
       _client = factory.CreateClient("XYZ_Api_Client");
   }
   // ...
}

或者，您可以在注册MyCustomClient时传递指定的实例。

注册工厂和自定义客户端：

builder.Services.AddHttpClient("XYZ_Api_Client", config =>
{
    var url = "https://example.com/api";
    config.BaseAddress = new Uri(url);
});

// specify the factory for your class 
builder.Services.AddSingleton<MyCustomClient>(sp => 
{
    var factory = sp.GetService<IHttpClientFactory>();
    var httpClient = factory.CreateClient("XYZ_Api_Client");
    
    return new MyCustomClient(httpClient);
});

然后在你们班：

public class MyCustomClient
{
   private readonly HttpClient _client;
   public MyCustomClient(HttpClient client)
   {
       _client = client;
   }
   // ...
}

您也可以这样做：

// register the named client with the name of the class
builder.Services.AddHttpClient("MyCustomClient", config =>
{
    config.BaseAddress = new Uri("https://example.com/api");
});

// no need to specify the name of the client
builder.Services.AddHttpClient<MyCustomClient>();

AddHttpClient<TClient>(IServiceCollection)所做的是

将IHttpClientFactory和相关服务添加到IServiceCollection，并配置TClient类型和命名HttpClient之间的绑定。客户端名称将设置为TClient的全名。

您可以找到完整的文档这里。