从配置文件配置 HttpClient/HttpMessageHandler

Posted 2023-03-27

【中文标题】从配置文件配置 HttpClient/HttpMessageHandler

【英文标题】：Configuring HttpClient/HttpMessageHandler from config file

【发布时间】：2021-12-31 13:43:03

【问题描述】：

我的 appsettings.json 文件包含以下部分。

"TrackAndTrace": 
  "DebugBaseUrl": "https://localhost:44360/api",
  "BaseUrl": "https://example.com/api",
  "Username": "Username",
  "Password": "Password",
  "CompanyCode": "CODE"
,

然后我将HttpClient 配置如下：

services.AddHttpClient<TestApi>()
    .ConfigurePrimaryHttpMessageHandler(() =>
    
        return new HttpClientHandler()
        
           // I want to incorporate this somehow:
           // services.Configure<TrackAndTraceSettings>(Configuration.GetSection("TrackAndTrace"))
           Credentials = new NetworkCredential(????, ???),
        ;
    );

我的问题是：如何从此处的配置文件中获取用户名和密码，并将其分配给HttpClientHandler.Credentials？

理想情况下，它可以以一种有效的方式完成，只需要从设置文件中读取一次。

【参考方案1】：

你可以使用

var credentials = Configuration.GetSection("TrackAndTrace").Get<TrackAndTrace>();

TrackAndTrace 模型应该是这样的；

public class TrackAndTrace
    public string DebugBaseUrl get;set;
    public string BaseUrl get;set;
    public string Username get;set;
    public string Password get;set;
    public string CompanyCode get;set;

然后你必须配置服务；

var credentials = Configuration.GetSection("TrackAndTrace").Get<TrackAndTrace>();
services.AddHttpClient<TestApi>()
    .ConfigurePrimaryHttpMessageHandler(() =>
    
        return new HttpClientHandler()
        
           Credentials = new NetworkCredential(credentials.Username, credentials.Password),
        ;
    );

【参考方案2】：

使用overload for ConfigurePrimaryHttpMessageHandler that accepts a callback with IServiceProvider parameter。

// assuming you've set up the configuration in ConfigureServices method:
// services.Configure<TrackAndTraceSettings>(Configuration.GetSection("TrackAndTrace"))

services.AddHttpClient<TestApi>()
    .ConfigurePrimaryHttpMessageHandler((serviceProvider) =>
    
        var config = serviceProvider.GetRequiredService<IOptions<TrackAndTraceSettings>>().Value;
        return new HttpClientHandler()
        
           Credentials = new NetworkCredential(config.Username, config.Password),
        ;
    );