c Windows窗体上传图片到服务器

using System;
using System.IO;
using System.Net.Http;
using System.Windows.Forms;

public partial class Form1 : Form
{
    private HttpClient client = new HttpClient();

    public Form1()
    {
        InitializeComponent();
    }

    private async void btnUpload_Click(object sender, EventArgs e)
    {
        OpenFileDialog openFileDialog = new OpenFileDialog
        {
            Filter = "Image files (*.png;*.jpeg;*.jpg;*.bmp)|*.png;*.jpeg;*.jpg;*.bmp"
        };

        if (openFileDialog.ShowDialog() == DialogResult.OK)
        {
            string filePath = openFileDialog.FileName;
            using (var content = new MultipartFormDataContent())
            {
                var fileContent = new ByteArrayContent(File.ReadAllBytes(filePath));
                fileContent.Headers.ContentType = MediaTypeHeaderValue.Parse("multipart/form-data");
                content.Add(fileContent, "file", Path.GetFileName(filePath));

                HttpResponseMessage response = await client.PostAsync("http://yourserver.com/upload", content);
                if (response.IsSuccessStatusCode)
                {
                    MessageBox.Show("Upload successful!");
                }
                else
                {
                    MessageBox.Show("Upload failed: " + response.ReasonPhrase);
                }
            }
        }
    }
}

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using System.IO;
using System.Threading.Tasks;

[Route("api/[controller]")]
[ApiController]
public class UploadController : ControllerBase
{
    private readonly string _uploadPath = "wwwroot/uploads";

    [HttpPost]
    public async Task<IActionResult> UploadFile(IFormFile file)
    {
        if (file == null || file.Length == 0)
            return BadRequest("No file uploaded.");

        var filePath = Path.Combine(_uploadPath, file.FileName);

        using (var stream = new FileStream(filePath, FileMode.Create))
        {
            await file.CopyToAsync(stream);
        }

        return Ok(new { message = "File uploaded successfully." });
    }
}