Multipart body length limit exceeded exception

I found the solution for this problem after reading some posts in GitHub. Conclusion is that they have to be set in the Startup class. For example:

public void ConfigureServices(IServiceCollection services)
{
        services.AddMvc();
        services.Configure<FormOptions>(x => {
            x.ValueLengthLimit = int.MaxValue;
            x.MultipartBodyLengthLimit = int.MaxValue; // In case of multipart
        })
 }

This will solve the problem. However they also indicated that there is a [RequestFormSizeLimit] attribute, but I have been unable to reference it yet.

Alternatively use the attribute, so the equivalent for an action as resolved by Transcendant would be:

[RequestFormLimits(ValueLengthLimit = int.MaxValue, MultipartBodyLengthLimit = int.MaxValue)]

If you use int.MaxValue (2,147,483,647) for the value of MultipartBodyLengthLimit as suggested in other answers, you'll be allowing file uploads of approx. 2Gb, which could quickly fill up disk space on a server. I recommend instead setting a constant to limit file uploads to a more sensible value e.g. in Startup.cs

using MyNamespace.Constants;
public void ConfigureServices(IServiceCollection services)
{
        ... other stuff
        services.Configure<FormOptions>(options => {
            options.MultipartBodyLengthLimit = Files.MaxFileUploadSizeKiloBytes;
        })
 }

And in a separate constants class:

namespace MyNamespace.Constants
{
    public static class Files
    {
        public const int MaxFileUploadSizeKiloBytes = 250000000; // max length for body of any file uploaded
    }
}

in case some one still face this problem i've created a middle-ware which intercept the request and create another body

    public class FileStreamUploadMiddleware
    {
        private readonly RequestDelegate _next;

        public FileStreamUploadMiddleware(RequestDelegate next)
        {
            _next = next;
        }

        public async Task Invoke(HttpContext context)
        {
            if (context.Request.ContentType != null)
            {
                if (context.Request.Headers.Any(x => x.Key == "Content-Disposition"))
                {
                    var v = ContentDispositionHeaderValue.Parse(
                        new StringSegment(context.Request.Headers.First(x => x.Key == "Content-Disposition").Value));
                    if (HasFileContentDisposition(v))
                    {
                        using (var memoryStream = new MemoryStream())
                        {
                            context.Request.Body.CopyTo(memoryStream);
                            var length = memoryStream.Length;
                            var formCollection = context.Request.Form =
                                new FormCollection(new Dictionary<string, StringValues>(),
                                    new FormFileCollection()
                                        {new FormFile(memoryStream, 0, length, v.Name.Value, v.FileName.Value)});
                        }
                    }
                }
            }

            await _next.Invoke(context);
        }

        private static bool HasFileContentDisposition(ContentDispositionHeaderValue contentDisposition)
        {
            // this part of code from  https://github.com/aspnet/Mvc/issues/7019#issuecomment-341626892
            return contentDisposition != null
                   && contentDisposition.DispositionType.Equals("form-data")
                   && (!string.IsNullOrEmpty(contentDisposition.FileName.Value)
                       || !string.IsNullOrEmpty(contentDisposition.FileNameStar.Value));
        }
    }

and in the controller we can fetch the files form the request

        [HttpPost("/api/file")]
        public IActionResult GetFile([FromServices] IHttpContextAccessor contextAccessor,
            [FromServices] IHostingEnvironment environment)
        {
            //save the file
            var files = Request.Form.Files;
            foreach (var file in files)
            {
                var memoryStream = new MemoryStream();
                file.CopyTo(memoryStream);

                var fileStream = File.Create(
                    $"{environment.WebRootPath}/images/background/{file.FileName}", (int) file.Length,
                    FileOptions.None);
                fileStream.Write(memoryStream.ToArray(), 0, (int) file.Length);

                fileStream.Flush();
                fileStream.Dispose();

                memoryStream.Flush();
                memoryStream.Dispose();
            }

            return Ok();
        }

you can improve the code for your needs eg: add form parameters in the body of the request and deserialize it.

its a workaround i guess but it gets the work done.