IFormFile always return null in asp.net core 2.1

Question

Api method is looks like below

    [HttpPost]
    public async Task> MediaBrand(IFormFile file, int brandId)
         


        

Answer 1

Change your method argument to take below model and add [FromForm], it should work.

public class FileUploadViewModel
{
    public IFormFile File { get; set; }
    public int BrandId { get; set; }
}

public async Task<BaseListResponse<MediaStorageModel>> MediaBrand([FromForm] FileUploadViewModel viewModel)

Answer 2

I have found a workaround to make it work:

Use HttpPut instead of HttPost on the controller action.

I was also surprised by this behavior. If someone can explain why it fixes the issue, it would help me.

Answer 3

In your form use

enctype="multipart/form-data"

Answer 4

In my case it works as follows in net core

Controller:

[HttpPost]
public IActionResult ReadFormFile([FromForm]IFormFile miCsv)
{


}

Request body: Use as key the same name as the parameter

Request Header: Use as Content-Type: multipart/form-data; boundary=xxxxxxxxxxx the boundary can be any value

Answer 5

If you use javascript and FormData object you need set the name of each file to 'files'

this.files.forEach((f) => {
         formData.append("files", f, `${this.path}/${f.name}`);
      }); 

if you use other name in your post you need to set it in the attribute of the post method

formData.append("someName", f, `${this.path}/${f.name}`);

 public async Task<IActionResult> Post([FromForm(Name ="someName")] List<IFormFile> files)

Dont forget to set content-type

'Content-Type': 'multipart/form-data'