C# ASP.NET核心类型客户端中的IHttpClientFactory
当我尝试为HttpClient使用类型化客户端时,我收到一个错误,如下所述: 以下是我的设置: Startup.cs:C# ASP.NET核心类型客户端中的IHttpClientFactory,c#,asp.net-core,dependency-injection,dotnet-httpclient,asp.net-core-2.1,C#,Asp.net Core,Dependency Injection,Dotnet Httpclient,Asp.net Core 2.1,当我尝试为HttpClient使用类型化客户端时,我收到一个错误,如下所述: 以下是我的设置: Startup.cs: public void ConfigureServices(IServiceCollection services) { services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1); services.AddDefaultAWSOptions(Configuratio
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
services.AddDefaultAWSOptions(Configuration.GetAWSOptions());
services.AddHttpClient<IPStackService>(c =>
{
c.BaseAddress = new Uri(Configuration["IPStackURL"]);
});
services.AddHttpContextAccessor();
services.AddTransient<IIPStackService, IPStackService>();
}
控制器:
[Route("api/[controller]")]
[ApiController]
public class RenderController : ControllerBase
{
private IConfiguration _configuration;
private readonly ILogger _logger;
private IIPStackService _ipMetaDataService;
public RenderController(IConfiguration configuration,
ILogger<RenderController> logger,
IIPStackService ipStackService)
{
_configuration = configuration;
_ipStackService = ipStackService;
_logger = logger;
}
[HttpGet]
[ProducesResponseType(StatusCodes.Status200OK)]
[Produces("text/plain")]
public async Task<ActionResult> GetAsync(string hostId, string clientUtc)
{
var ip = Common.ResolveIPAddress(HttpContext);
var ipMetaData = await _ipStackService.GetByIPAsync(ip, _configuration["AccessKey"]);
// removed for clarity
return allowed ? Ok(true) : Ok(null);
}
}
服务:
public class IPStackService : IIPStackService
{
private readonly ILogger _logger;
private readonly HttpClient _httpClient;
public IPStackService(ILogger<IPStackService> logger, HttpClient client)
{
_logger = logger;
_httpClient = client;
}
public async Task<IPMetaDataModel> GetByIPAsync(string ip, string accessKey)
{
var ipMetaData = new IPMetaDataModel();
var response = await _httpClient.GetAsync($"/{ip}?access_key={accessKey}");
response.EnsureSuccessStatusCode();
// removed for clarity
return ipMetaData;
}
}
收到错误:
处理请求时发生未处理的异常。
InvalidOperationException:无法解析类型的服务
尝试激活时出现“System.Net.Http.HttpClient”
“WebScreen.Gate.Services.IPStackService”。
Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateArgumentCallSitesType
serviceType,Type implementationType,CallSiteChain CallSiteChain,
ParameterInfo[]参数,bool throwIfCallSiteNotFound
如何为HttpClient正确设置类型化客户端?IPStackService代码反射的Activator在DI集合中找不到HttpClient,这就是为什么会出现专门针对services.AddTransient的异常
顺便说一句,您在DI集合中添加了两次服务:
服务。AddHttpClient。。。;。
服务.AddTransient;
您只需要一个,因为您使用的是类型化客户端,所以您可以通过删除第二个并保留第一个来解决问题,并通过将契约添加到实现中来稍微修改第一个,如下所示:
services.AddHttpClient<IIPStackService, IPStackService>(c =>
{
c.BaseAddress = new Uri(Configuration["IPStackURL"]);
});
IPStackService代码反射的Activator在DI集合中找不到HttpClient,这就是为什么会出现专门针对services.AddTransient的异常
顺便说一句,您在DI集合中添加了两次服务:
服务。AddHttpClient。。。;。
服务.AddTransient;
您只需要一个,因为您使用的是类型化客户端,所以您可以通过删除第二个并保留第一个来解决问题,并通过将契约添加到实现中来稍微修改第一个,如下所示:
services.AddHttpClient<IIPStackService, IPStackService>(c =>
{
c.BaseAddress = new Uri(Configuration["IPStackURL"]);
});
恕我直言,我认为使用services.AddTransient;添加HttpClient不是一个好主意;。这将为每个请求创建HttpClient,如果HttpClient实例未正确处理,则可能导致套接字打开。然而,AddHttpClient使用IHttpClientFactory并将在幕后管理HttpMessageHandler的生命周期。我完全同意你所说的。我刚才提到它是一种解决方案,以防他想采用第二种方法。我认为使用services.AddTransient;添加HttpClient不是一个好主意;。这将为每个请求创建HttpClient,如果HttpClient实例未正确处理,则可能导致套接字打开。然而,AddHttpClient使用IHttpClientFactory并将在幕后管理HttpMessageHandler的生命周期。我完全同意你所说的。我刚才提到这是一个解决方案,以防他想采用第二种方法。