API OAuth2 Token Management是一种重要的方案，它使用IdentityModel.AspNetCore实现AuthorizationCodeTokenRequest。该解决方法需要遵循以下步骤：

1. 在NuGet中安装IdentityModel.AspNetCore。

2. 添加以下代码段到Startup类的ConfigureServices方法中，以便设置IdentityServer4作为身份提供者。

using Microsoft.AspNetCore.Authentication.Cookies; using Microsoft.AspNetCore.Authentication.OpenIdConnect; using Microsoft.AspNetCore.Builder; using Microsoft.AspNetCore.Hosting; using Microsoft.Extensions.Configuration; using Microsoft.Extensions.DependencyInjection; using Microsoft.Extensions.Logging; using System.IdentityModel.Tokens.Jwt; using IdentityModel.AspNetCore.OAuth2Introspection; using IdentityModel;

public class Startup { public Startup(IConfiguration configuration) { Configuration = configuration; }

public IConfiguration Configuration { get; }

public void ConfigureServices(IServiceCollection services)
{
    JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Clear();

    services.AddAuthentication(options =>
    {
        options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
        options.DefaultChallengeScheme = OpenIdConnectDefaults.AuthenticationScheme;
    })
        .AddCookie()
        .AddOpenIdConnect(options =>
        {
            options.Authority = "https://demo.identityserver.io";
            options.SignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;

            options.ClientId = "interactive";
            options.ResponseType = OidcConstants.ResponseTypes.Code;
            options.Scope.Clear();
            options.Scope.Add("openid");
            options.Scope.Add("profile");
            options.Scope.Add("email");

            options.SaveTokens = true;
            options.GetClaimsFromUserInfoEndpoint = true;
        });
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    app.UseAuthentication();
    app.UseMvc();
}

}

3. 然后，即可使用AuthorizationCodeTokenRequest将OAuth2令牌交换为访问令牌：

var client = new HttpClient();

var disco = await client.GetDiscoveryDocumentAsync("https://demo.identityserver.io"); if (disco.IsError) throw new Exception(disco.Error);

var token = await client.RequestAuthorizationCodeTokenAsync(new AuthorizationCodeTokenRequest { Address = disco.TokenEndpoint, ClientId = "interactive", Client