重复调用 AddHttpClient 会互相覆盖吗？

问题描述

我有一个 NuGet 包，里面有这样的代码：

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

还有另一个包含类似代码的 Nuget 项目：

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()

我担心如果我将它们分开，则只有一个有效。我查看了 code on GitHub，它为每次调用返回一个 newed 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。

同名客户端可以单独“添加”吗？还是会覆盖？

解决方法

根据此处的内部评论，我认为可以为同名客户完成此操作。

    // 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;
        }
    }

Source

客户端选项配置将聚合为一个选项。