protected virtual async Task GetActionApiDescriptionModel(IAbpMethodInvocation invocation)
    {
        var clientConfig = ClientOptions.HttpClientProxies.GetOrDefault(typeof(TService)) ??      //获取远程服务名称
                           throw new AbpException($"Could not get DynamicHttpClientProxyConfig for {typeof(TService).FullName}.");
        var remoteServiceConfig = await RemoteServiceConfigurationProvider.GetConfigurationOrDefaultAsync(clientConfig.RemoteServiceName);//获取远程服务端点配置
        var client = HttpClientFactory.Create(clientConfig.RemoteServiceName); //创建HttpClient

        return await ApiDescriptionFinder.FindActionAsync(   
            client,
            remoteServiceConfig.BaseUrl,  //远程服务地址
            typeof(TService),       
            invocation.Method
        );
    }

public async Task FindActionAsync(
        HttpClient client,
        string baseUrl,
        Type serviceType,
        MethodInfo method)
    {
        var apiDescription = await GetApiDescriptionAsync(client, baseUrl); //获取Api描述信息并缓存结果

        //TODO: Cache finding?

        var methodParameters = method.GetParameters().ToArray();

        foreach (var module in apiDescription.Modules.Values)
        {
            foreach (var controller in module.Controllers.Values)
            {
                if (!controller.Implements(serviceType))  //不继承接口跳过，所以写控制器为什么需要要继承服务接口的作用之一便在于此
                {
                    continue;
                }

                foreach (var action in controller.Actions.Values)
                {
                    if (action.Name == method.Name && action.ParametersOnMethod.Count == methodParameters.Length) //签名是否匹配
                    {
                        /*省略部分代码 */
                    }
                }
            }
        }

        throw new AbpException($"Could not found remote action for method: {method} on the URL: {baseUrl}");
    }

    public virtual async Task GetApiDescriptionAsync(HttpClient client, string baseUrl)
    {
        return await Cache.GetAsync(baseUrl, () => GetApiDescriptionFromServerAsync(client, baseUrl)); //缓存结果
    }

   protected virtual async Task GetApiDescriptionFromServerAsync(
        HttpClient client,
        string baseUrl)
    {
        //构造请求信息
        var requestMessage = new HttpRequestMessage(
            HttpMethod.Get,
            baseUrl.EnsureEndsWith('/') + "api/abp/api-definition"
        );

        AddHeaders(requestMessage); //添加请求头

        var response = await client.SendAsync(   //发送请求并获取响应结果
            requestMessage,
            CancellationTokenProvider.Token
        );

        if (!response.IsSuccessStatusCode)
        {
            throw new AbpException("Remote service returns error! StatusCode = " + response.StatusCode);
        }

        var content = await response.Content.ReadAsStringAsync();

        var result = JsonSerializer.Deserialize(content, DeserializeOptions);

        return result;
    }