在.Net Core3.0控制台应用程序中使用HttpClient上传文件

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

class Program
{
    static async Task Main(string[] args)
    {
        using (var httpClient = new HttpClient())
        {
            // 在这里进行文件上传操作
        }
    }
}

var fileContent = new ByteArrayContent(File.ReadAllBytes("path/to/file"));
fileContent.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("multipart/form-data");

var formData = new MultipartFormDataContent();
formData.Add(fileContent, "file", "filename.ext");

var response = await httpClient.PostAsync("https://your-upload-url", formData);

if (response.IsSuccessStatusCode)
{
    Console.WriteLine("文件上传成功！");
}
else
{
    Console.WriteLine("文件上传失败！");
}