Asp.Core API尝试上载文件并将其存储在数据库中:错误: 415:不支持的媒体类型

const formData = new FormData();
formData.append('file', fileInput.files[0]);

fetch('/api/upload', {
    method: 'POST',
    body: formData
});

[ApiController]
[Route("api/[controller]")]
public class UploadController : ControllerBase
{
    [HttpPost]
    public async Task<IActionResult> UploadFile([FromForm] IFormFile file)
    {
        if (file == null || file.Length == 0)
            return BadRequest("No file uploaded.");

        using var memoryStream = new MemoryStream();
        await file.CopyToAsync(memoryStream);

        // 将文件内容存储到数据库或其他存储机制
        // ...

        return Ok("File uploaded successfully.");
    }
}

[HttpPost]
public async Task<IActionResult> UploadFile()
{
    if (!Request.HasFormContentType)
        return BadRequest("Request content type must be multipart/form-data.");

    var boundary = Request.GetMultipartBoundary();
    var reader = new MultipartReader(boundary, Request.Body);

    var section = await reader.ReadNextSectionAsync();
    while (section != null)
    {
        var fileSection = section.AsFileSection();
        if (fileSection != null)
        {
            using var stream = new MemoryStream();
            await fileSection.FileStream.CopyToAsync(stream);
            // 处理文件流
        }
        section = await reader.ReadNextSectionAsync();
    }

    return Ok("Files uploaded successfully.");
}