How to create an API controller that will handles multipart/data

Question

Hello,

I use ASP NETCore 6, How to create an API controller that will handles multipart/data with the following keys:

tifFile --> File

hostName --> string

accessCode --> string

I tried the following using postman, it goes there but I don't have an idea on how to extract the key and its value?

[HttpPost]
[Route("/api/AWS/Upload")]
[AllowAnonymous]
public async Task awsUploadAsync() 
{
    // how to get the tifFile, hostName, and accessCode value here
}

Answer 1

Hi @Dondon510,

You could retrieve values from HttpContext like following:

public async Task awsUploadAsync()
{
    var form = await HttpContext.Request.ReadFormAsync();
    // Retrieve form fields
    var hostName = form["hostName"].ToString();
    var accessCode = form["accessCode"].ToString();
    var tifFile = form.Files["tifFile"];
}

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Answer 2

The official documentation covers uploading files and posting form inputs.

https://learn.microsoft.com/en-us/aspnet/core/mvc/models/file-uploads?view=aspnetcore-9.0

First, define a model that matches the fields you wish to upload.

    public class UploadModel
    {
        public IFormFile? TifFile { get; set; }
        public string HostName { get; set; } = string.Empty;
        public string AccessCode { get; set; } = string.Empty;
    }

Add the model type in the action signature. Finally, add the [FromForm] attribute to let the action know it should expect a content type of multipart/form-data.

    [Route("api/[controller]")]
    [ApiController]
    public class FileUploadController : ControllerBase
    {
        [HttpPost]
        public IActionResult awsUploadAsync([FromForm] UploadModel model)
        {
            return Ok(model);
        }
    }