HttpClientStudy/HttpClientStudy.Core/SimpleHttpClient.cs

using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Net.Http;
using System.Net.Mime;
using System.Net;

namespace HttpClientStudy.Core
{
    /// <summary>
    /// 简单 HttpClient 包装类
    /// </summary>
    public class SimpleHttpClient
    {
        #region Get请求
        public string Get(string url)
        {
            HttpClient client = new HttpClient();
            //可以统一设置HttpClient属性：HttpClient可以使用统一设置进行多次请求。
            //client.BaseAddress = new Uri(url);
            //client.DefaultRequestHeaders.Add("Accept", "application/json");
            //client.DefaultRequestVersion = HttpVersion.Version10;
            //client.DefaultVersionPolicy = HttpVersionPolicy.RequestVersionOrHigher;
            //client.Timeout = TimeSpan.FromSeconds(60);
            //client.CancelPendingRequests();

            //只有Send是同步方法，其它全为异步方法。

            //Send同步方法，需要HttpRequestMessage参数
            HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, url);
            var response = client.Send(request);

            response.EnsureSuccessStatusCode();
            //或者
            if (response.IsSuccessStatusCode)
            {
                //业务逻辑
            }

            //状态码
            if (response is { StatusCode: HttpStatusCode.OK })
            {
                //业务逻辑
            }

            //请求头
            if (response is { Headers.ETag: null })
            {
                //业务逻辑
            }

            var result = response.Content.ReadAsStringAsync().Result;

            return result;
        }

        public async Task<string> GetAsync(string url)
        {
            HttpClient client = new HttpClient();
            var response = await client.GetAsync(url);

            response.EnsureSuccessStatusCode();

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

            return result;
        }

        public TResult? GetJson<TResult>(string url)
        {
            HttpClient client = new HttpClient();

            HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, url);
            var response = client.Send(request);

            response.EnsureSuccessStatusCode();
            if (response.Content.Headers.ContentType?.MediaType != MediaTypeNames.Application.Json)
            {
                throw new HttpRequestException("响应不是 json 格式！");
            }

            var result = response.Content.ReadFromJsonAsync<TResult>().Result;

            return result;
        }

        public async Task<TResult?> GetJsonAsync<TResult>(string url)
        {
            HttpClient client = new HttpClient();

            var response = await client.GetAsync(url);

            response.EnsureSuccessStatusCode();
            if (response.Content.Headers.ContentType?.MediaType != MediaTypeNames.Application.Json)
            {
                throw new HttpRequestException("响应不是 json 格式！");
            }

            var result = await response.Content.ReadFromJsonAsync<TResult>();

            return result;
        }
        #endregion
    }
}