ColinChang.BigFileForm 1.0.2

What this is about?

an Asp.Net Core middleware that can process multiple form parameters including big files and texts in a POST/PUT method by overriding object HttpConext.Request.Form and HttpConext.Request.Form.Files.

How to use it?

this middleware is easy to be used by a few steps.

configuration

configures the file size limitation in appsettings.json.

{
  "BigFileFormOptions": {
    "MinBodySize": 5242880,
    "MaxBodySize": 209715200
  }
}

config the options in Startup.ConfigureServices

public void ConfigureServices(IServiceCollection services)
{
    services.Configure<BigFileFormOptions>(Configuration.GetSection(nameof(BigFileFormOptions)));
    services.AddControllers();
}

use the middleware

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    app.UseRouting();

    //use big file form middleware
    app.UseBigFileForm();
    app.UseEndpoints(endpoints => { endpoints.MapControllers(); });
}

try it

after using this middleware, you could get your big file and text parameters by Request.Form.Files and Request.Forms when you try to upload a big file between MinBodySize and MaxBodySize. It can only work in a POST or PUT method.

[ApiController]
[Route("[controller]")]
public class TestController : ControllerBase
{
    private ILogger _logger;
    public TestController(ILogger<TestController> logger) => _logger = logger;

    [HttpPost]
    [DisableFormValueModelBinding]
    [DisableRequestSizeLimit]
    public async Task PostAsync()
    {
        var releaseNotes = Request.Form["releasenotes"];
        _logger.LogInformation(releaseNotes);

        var app = Request.Form.Files["app"];
        await using var fileStream = System.IO.File.Create(app.FileName);
        await app.CopyToAsync(fileStream);
    }
}

file size limitation

when we try to upload a big file, we have to know both the Kestrel server and default form have its limitation. We could adjust them by configuring KestrelServerOptions and FormOptions.

{
  "KestrelServerOptions": {
    "Limits": {
      "KeepAliveTimeout": 300,
      "RequestHeadersTimeout": 300,
      "MaxRequestBodySize": 209715200,
      "Http2": {
        "MaxStreamsPerConnection": 104857600,
        "MaxFrameSize": 16777215
      }
    }
  },
  "BigFileFormOptions": {
    "MinBodySize": 5242880,
    "MaxBodySize": 209715200
  }
}

public void ConfigureServices(IServiceCollection services)
{
    services
        // modify kestrel limitation
        .Configure<KestrelServerOptions>(Configuration.GetSection(nameof(KestrelServerOptions)))
        // modify default form limitation
        .Configure<FormOptions>(options =>
        {
            var maxRequestBodySize =
                int.Parse(Configuration["KestrelServerOptions:Limits:MaxRequestBodySize"]);
            options.ValueLengthLimit = maxRequestBodySize;
            options.MultipartBodyLengthLimit = maxRequestBodySize;
        })
        // big file form
        .Configure<BigFileFormOptions>(Configuration.GetSection(nameof(BigFileFormOptions)));

    services.AddControllers();
}

Sample

Sample project shows how to use this middleware.