如何使用IHttpClientFactory在Blazor Server中配置HttpClient基址

问题描述

我正在尝试使用HttpClient在Blazor服务器中配置IHttpClientFactory的基地址，但遇到运行时异常：

    services.AddHttpClient("apiclient",(provider,client) =>
    {
        var uriHelper = provider.GetrequiredService<NavigationManager>();
        client.BaseAddress = new Uri(uriHelper.BaseUri);
    });

system.invalidOperationException: 'Cannot resolve scoped service 'Microsoft.AspNetCore.Components.NavigationManager' from root provider.'

有人知道这里可能是什么问题吗？

解决方法

在ConfigureServices期间基本URL不可用，您可以传递它或创建服务：

services.AddHttpClient();
services.AddTransient<ApiService>();

服务：

public class ApiService
{
    public ApiService(HttpClient httpClient,NavigationManager navigationManager)
    {
        HttpClient = httpClient;
        NavigationManager = navigationManager;
        HttpClient.BaseAddress = new Uri(NavigationManager.BaseUri);
    }

    public HttpClient HttpClient { get; }
    public NavigationManager NavigationManager { get; }
}

一个组件：

   Base Address : @ApiService.HttpClient.BaseAddress
        
    @code {
        [Inject]
        public ApiService ApiService { get; set; }   
        
    }

,

将此添加到服务中

    var baseAddress = "http://address-goes-here/";
    services.AddScoped(sp =>
    {
        var client = new HttpClient();
        client.BaseAddress = new Uri(baseAddress);
        return client;
    });