在webapi中发起HttpPost请求

1.第一步,在启动文件添加

builder.Services.AddHttpClient();

实体类: 

public class SearchReq
{
    public string Name { get; set; }
    public string Description { get; set; }
    public int PageIndex { get; set; }
    public int PageSize { get; set; }
}

using Microsoft.AspNetCore.Mvc;
using System.Text;
using System.Text.Json;
using WebApplication8._6.Model;
using static System.Net.Mime.MediaTypeNames;

namespace WebApplication8._6.Controllers
{
    [Route("api/[controller]/[action]")]
    [ApiController]
    public class ValuesController : ControllerBase
    {
        private readonly IHttpClientFactory _httpClientFactory;
        public ValuesController(IHttpClientFactory httpClientFactory)
        {
            _httpClientFactory = httpClientFactory;
        }
        [HttpPost]
        public string Test()
        {
            return "value1";
        }

        /// <summary>
        /// 发起请求调用Test方法
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public async Task<string> PostTest()
        {
            SearchReq req = new SearchReq();
            req.Name = "zhangshang";
            req.Description = "Description";
            req.PageSize = 10;
            req.PageIndex = 1;
            //包装参数
            var reqJson = new StringContent(
                JsonSerializer.Serialize(req),
                Encoding.UTF8,
                Application.Json
            );
            var httpClient = _httpClientFactory.CreateClient();
            using var httpResponseMessage = await httpClient.PostAsync("https://localhost:7279/api/Values/Test", reqJson);
            var readStr = await httpResponseMessage.Content.ReadAsStringAsync();
            return readStr;
        }

    }
}