c# - 对 AddHttpClient 的重复调用会相互覆盖吗？

Question

我有一个 NuGet 包，其中包含这样的代码：

services.AddHttpClient("CompanyStandardClient").AddCompanyAuthenticationHeaders();

还有另一个 Nuget 项目，其中包含这样的代码：

services.AddHttpClient("CompanyStandardClient").AddCompanyHeaderPropagation();

基本上，一个 NuGet 设置我公司的身份验证，另一个设置公司的标头传播。

我通常会这样做：

services.AddHttpClient("CompanyStandardClient").AddCompanyAuthenticationHeaders().AddCompanyHeaderPropagation()

我担心如果我分开做，只有一个会生效。我查看了GitHub 上的代码new，它为每个调用返回一个ed DefaultHttpClientBuilder。

return new DefaultHttpClientBuilder(services, name);

但我不确定这是否意味着之前的条目被覆盖了。

可以单独“添加”同一个命名的客户端吗？还是会覆盖？

标签： c#asp.net-coreasp.net-core-3.1

Answer 1

我认为可以根据此处的内部评论为同一个命名的客户完成。

    // See comments on HttpClientMappingRegistry.
    private static void ReserveClient(IHttpClientBuilder builder, Type type, string name, bool validateSingleType)
    {
        var registry = (HttpClientMappingRegistry)builder.Services.Single(sd => sd.ServiceType == typeof(HttpClientMappingRegistry)).ImplementationInstance;
        Debug.Assert(registry != null);

        // Check for same name registered to two types. This won't work because we rely on named options for the configuration.
        if (registry.NamedClientRegistrations.TryGetValue(name, out Type otherType) &&

            // Allow using the same name with multiple types in some cases (see callers).
            validateSingleType &&

            // Allow registering the same name twice to the same type.
            type != otherType)
        {
            string message =
                $"The HttpClient factory already has a registered client with the name '{name}', bound to the type '{otherType.FullName}'. " +
                $"Client names are computed based on the type name without considering the namespace ('{otherType.Name}'). " +
                $"Use an overload of AddHttpClient that accepts a string and provide a unique name to resolve the conflict.";
            throw new InvalidOperationException(message);
        }

        if (validateSingleType)
        {
            registry.NamedClientRegistrations[name] = type;
        }
    }

来源

客户端选项配置将聚合为单个选项。