使用 .Net 客户端应用程序使用 Web API

Question

我一直在学习一些教程（例如 https://docs.microsoft.com/en-us/aspnet/web-api/overview/advanced/calling-a-web-api-from-a-net-client）并尝试检索作业列表并在我的 .Net 控制台应用程序中打印出来。

我正在使用的测试数据位于 https://boards-api.greenhouse.io/v1/boards/vaulttec/jobs 并提供给 client.BaseAddress.

因为我能够编译和运行教程成功，所以我只是使用相同的代码并将其中的一些更改为运行上面的测试数据（见下文）。

using System;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

namespace GreenhouseJobs
{
public class Job
{
    public string Id { get; set; }
    public string Title { get; set; }
    public string Location { get; set; }
    public DateTime LastUpdated { get; set; }
}

class GreenhouseJobsClient
{
    static HttpClient client = new HttpClient();

    static void ShowJob(Job job)
    {
        Console.WriteLine($"Id: {job.Id}\tTitle: " +
            $"{job.Title}\tLocation: {job.Location}\tLast Updated: {job.LastUpdated}");
    }

    static async Task<Uri> CreateJobAsync(Job job)
    {
        HttpResponseMessage response = await client.PostAsJsonAsync(
            "vaulttec/jobs", job);
        response.EnsureSuccessStatusCode();

        // return URI of the created resource.
        return response.Headers.Location;
    }

    static async Task<Job> GetJobAsync(string path)
    {
        Job job = null;
        HttpResponseMessage response = await client.GetAsync(path);
        if (response.IsSuccessStatusCode)
        {
            job = await response.Content.ReadAsAsync<Job>();
        }
        return job;
    }

    //static async Task<Product> UpdateProductAsync(Product product)
    //{
    //    HttpResponseMessage response = await client.PutAsJsonAsync(
    //        $"api/products/{product.Id}", product);
    //    response.EnsureSuccessStatusCode();

    //    // Deserialize the updated product from the response body.
    //    product = await response.Content.ReadAsAsync<Product>();
    //    return product;
    //}

    //static async Task<HttpStatusCode> DeleteProductAsync(string id)
    //{
    //    HttpResponseMessage response = await client.DeleteAsync(
    //        $"api/products/{id}");
    //    return response.StatusCode;
    //}

    static void Main()
    {
        RunAsync().GetAwaiter().GetResult();
        Console.ReadLine();
    }

    static async Task RunAsync()
    {
        // Update port # in the following line.
        client.BaseAddress = new Uri("https://boards-api.greenhouse.io/v1/boards/");
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(
            new MediaTypeWithQualityHeaderValue("application/json"));

        try
        {
            // Create a new product
            Job job = new Job
            {
                Id = "323232",
                Title = "Test",
                Location = "Test",
                LastUpdated = DateTime.Now
            };

            var url = await CreateJobAsync(job);
            Console.WriteLine($"Created at {url}");

            // Get the product
            job = await GetJobAsync(url.PathAndQuery);
            ShowJob(job);

            // Update the product
            //Console.WriteLine("Updating price...");
            //product.Price = 80;
            //await UpdateProductAsync(product);

            // Get the updated product
            //product = await GetProductAsync(url.PathAndQuery);
            //ShowProduct(product);

            // Delete the product
            //var statusCode = await DeleteProductAsync(product.Id);
            //Console.WriteLine($"Deleted (HTTP Status = {(int)statusCode})");

        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }

        Console.ReadLine();
    }
}

}

问题是，当我运行应用程序时，它没有 return 任何东西。错误信息："Response status code does not indicate success: 404 (Not Found)".

Answer 1

这行代码正在返回 404：

HttpResponseMessage response = await client.PostAsJsonAsync("vaulttec/jobs", job);

这是因为当您尝试发出 POST 请求时 URL https://boards-api.greenhouse.io/v1/boards/vaulttec/jobs returns 404。可能您需要获得授权才能创建工作。

不过，您可以向 URL 发出 GET 请求就好了。

Answer 2

这里有几个问题

您不仅要尝试检索，还要先创建。我不确定这个 api 是否支持 POST ，它可能不支持，因此是 404
作业实体不正确。如果您需要正确反序列化，则 Location 本身必须是一个对象，而不仅仅是一个字符串。这是 get call

https://pastebin.com/85NnAQY9

namespace ConsoleApp3
{

    public class JobsJson
    {
        public List<Job> Jobs { get; set; }
    }
    public class Job
    {
        public string Id { get; set; }
        public string Title { get; set; }
        public Location Location { get; set; }
        public DateTime LastUpdated { get; set; }
    }

    public class Location
    {
        public string Name { get; set; }
    }

    class GreenhouseJobsClient
    {
        static HttpClient client = new HttpClient();

        static void ShowJobs(List<Job> jobs)
        {
            foreach (var job in jobs)
            {
                Console.WriteLine($"Id: {job.Id}\tTitle: " +
                                  $"{job.Title}\tLocation: {job.Location}\tLast Updated: {job.LastUpdated}");
            }
        }


        static async Task<List<Job>> GetJobAsync(string path)
        {
            var jobs = new List<Job>();
            HttpResponseMessage response = await client.GetAsync(path);

            if (response.IsSuccessStatusCode)
            {
                var stringResponse = await response.Content.ReadAsStringAsync();
                var re = JsonConvert.DeserializeObject<JobsJson>(stringResponse);
                jobs = re.Jobs;
            }
            return jobs;
        }

        static void Main()
        {
            RunAsync().GetAwaiter().GetResult();
            Console.ReadLine();
        }

        static async Task RunAsync()
        {
            // Update port # in the following line.
            client.BaseAddress = new Uri("https://boards-api.greenhouse.io/v1/boards/");
            client.DefaultRequestHeaders.Accept.Clear();
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

            try
            {
                // Get the product
                var jobs = await GetJobAsync("vaulttec/jobs");
                ShowJobs(jobs);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }

            Console.ReadLine();
        }
    }
}

使用 .Net 客户端应用程序使用 Web API

Consume a Web API using a .Net Client App

.net

c#

api

console-application

web