我遇到过Netcore 2.1的一个问题,它将多个泛型类型的HttpClient添加到ServiceCollection中。这没有按预期工作,它给了我奇怪的结果。
考虑我的考试
var services = new ServiceCollection();
services.AddHttpClient<IHttpGenericClientFactory<test1>, HttpGenericClientFactory<test1>>(client =>
{
client.BaseAddress = new Uri("https://test1.com/");
});
services.AddHttpClient<IHttpGenericClientFactory<test2>, HttpGenericClientFactory<test2>>(client =>
{
client.BaseAddress = new Uri("https://test2.com/");
});
现在尝试解决每项服务时
var provider = services.BuildServiceProvider();
var service1 = provider.GetService<IHttpGenericClientFactory<test1>>();
var service2 = provider.GetService<IHttpGenericClientFactory<test2>>();
当我检查service1.BaseAddress时,值为“https://test2.com/”,service2.BaseAddress也是“https://test2.com/”。无论我尝试过什么,服务总是解析或引用已添加的最后一个通用类型服务。这是框架中的错误吗?任何人都知道为什么这不能正常工作?这绝对与通用类型的http客户端有关。
我的通用类和接口
public interface IHttpGenericClientFactory<out T3>
{
HttpClient HttpClient { get; set; }
Task<T1> Get<T1, T2>(T2 request, string path);
}
public class HttpGenericClientFactory<T3> : IHttpGenericClientFactory<T3>
{
public HttpClient HttpClient { get; set; }
public HttpGenericClientFactory(HttpClient httpClient) => this.HttpClient = httpClient;
public async Task<T1> Get<T1,T2>(T2 request, string path)
{
var response = await HttpClient.GetAsync(path);
response.EnsureSuccessStatusCode();
return await response.Content.ReadAsAsync<T1>();
}
}
您无法根据泛型类型参数的泛型类型参数中的差异进行解析。我可以推荐的最好的事情是创建具体的派生,然后你可以明确地引用:
public class Test1ClientFactory : HttpGenericClientFactory<Test1> {}
public class Test2ClientFactory : HttpGenericClientFactory<Test2> {}
然后:
services.AddHttpClient<Test1ClientFactory>(client =>
{
client.BaseAddress = new Uri("https://test1.com/");
});
services.AddHttpClient<Test2ClientFactory>(client =>
{
client.BaseAddress = new Uri("https://test2.com/");
});