How convert byte[] into a model

Question

I'm reading this answer to upload a file using MVC. I already have the file after a InputStream.Read but don't know how use it to create the IEnumerable<MyModel> so I can send it to db using EF. The file is a CSV file, I know the structure of.

public class MyViewModel
{
    [Required]
    public HttpPostedFileBase File { get; set; }
}

[HttpPost]
public ActionResult Index(MyViewModel model)
{
    if (!ModelState.IsValid)
    {
        return View(model);
    }

    byte[] uploadedFile = new byte[model.File.InputStream.Length];
    model.File.InputStream.Read(uploadedFile, 0, uploadedFile.Length);

    // now you could pass the byte array to your model and store wherever 
    // you intended to store it

    return Content("Thanks for uploading the file");
}

My Model:

public class PriceViewModel
{        
    public int PriceId { get; set; }

    public int? YearSelected { get; set; }
    public int? WeekSelected { get; set; }
    public int? StateSelected { get; set; }
}

what's the purpose of IEnumerable? You can directly assign byte array in your model stream. — Akash KC, May 02 '18 at 02:32
@AkashKC That is the question. How I do that? The file is a csv, I know the structure so I guess a validation process previous to assign to the model would be nice add to make sure the file have the correct structure — Juan Carlos Oropeza, May 02 '18 at 02:35
Can you please share your EF model so that we will know about IEnumerable — Akash KC, May 02 '18 at 02:39
Convert the bytes to string and then parse the CSV into the models. From there you can validate the data and save to database. CsvHelper should help a lot with that — Nkosi, May 02 '18 at 02:46
@Nkosi How I Convert the bytes to string ? I know how parse a string and the rest. — Juan Carlos Oropeza, May 02 '18 at 02:48

Nkosi · Accepted Answer · 2018-05-02T03:01:31.417

3

Convert the bytes to string

var csv = Encoding.UTF8.GetString(uploadedFile);

and then parse the CSV into the models.

CsvHelper should help a lot with that.

var textReader = new StringReader(csv);
var helper = new CsvHelper(textReader);
IEnumerable<PriceViewModel> records = helper.GetRecords<PriceViewModel>();

From there you can validate the data and save to database.

edited May 02 '18 at 03:01

answered May 02 '18 at 02:49

Nkosi

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Ok, I try that. But then why on the other question he does `model.File.InputStream.Read` – Juan Carlos Oropeza May 02 '18 at 02:52
They are copying the bytes from the stream into the array – Nkosi May 02 '18 at 02:53
Ok, I have something on the string. But my text contain spanish words and the accent letters appear with weirds signs instead. Did I damage the data durign the upload or during the conversion? – Juan Carlos Oropeza May 02 '18 at 02:54
But `File` is part of `MyViewModel` isnt an array – Juan Carlos Oropeza May 02 '18 at 02:56
You created the array here `byte[] uploadedFile = new byte[model.File.InputStream.Length];` and then copied the data from teh stream into that array – Nkosi May 02 '18 at 02:57
Ok, I see. Usually the method affect the objects, but in this case affect the parameters? – Juan Carlos Oropeza May 02 '18 at 03:00
Have to use Encoding.Default to read the accent words. And couldnt use GetRecords() because couldnt match my model so I just read by postion. – Juan Carlos Oropeza May 02 '18 at 04:11

How convert byte[] into a model

1 Answers1