Question

I need to validate a byte[] in my model as Required but whenever I use Data Annotation [Required] on it, it won’t do anything. Even if i choose a file it outputs error message.

Details:

Model:

Public class MyClass
{
   [Key]
   public int ID {get; set;}

   [Required]
   public string Name {get; set;}

   public byte[] Image {get; set;}

   [Required]
   public byte[] Template {get; set;}
}

View:

<div class="editor-label">
   <%:Html.LabelFor(model => model.Image) %>
</div>
<div class="editor-field">
   <input type="file" id="file1" name="files" />
</div>
<div class="editor-label">
   <%:Html.Label("Template") %>
</div>
<div class="editor-field"> 
   <input type="file" id="file2" name="files"/>
</div>
<p>
   <input type="submit" value="Create" />
</p>

I’ve looked around the posts and notice people use custom validation but they have used HttpPostedFileBase as types of files instead of byte[] like me, for some reason when I try to use the same it errors with a missing ID for it… Even though the model has it’s own ID declared.

EDIT:

Context – OnModelCreating additions for Report

modelBuilder.Entity<Report>().Property(p => p.Image).HasColumnType("image");
modelBuilder.Entity<Report>().Property(p => p.Template).HasColumnType("image");

note that i had to put image as ColumnType because of Byte array truncation to a length of 4000. error.

Controller:

public ActionResult Create(Report report, IEnumerable<HttpPostedFileBase> files)
    {

        if (ModelState.IsValid)
        {
            db.Configuration.ValidateOnSaveEnabled = false;

            if (files.ElementAt(0) != null && files.ElementAt(0).ContentLength > 0)
            {
                using (MemoryStream ms = new MemoryStream())
                {
                    files.ElementAt(0).InputStream.CopyTo(ms);
                    report.Image = ms.GetBuffer();
                }
            }

            if (files.ElementAt(1) != null && files.ElementAt(1).ContentLength > 0)
            {
                using (MemoryStream ms1 = new MemoryStream())
                {
                    files.ElementAt(1).InputStream.CopyTo(ms1);
                    report.Template = ms1.GetBuffer();
                }

            }
            db.Reports.Add(report);
            db.SaveChanges();

            //Temporary save method
            var tempID = 10000000 + report.ReportID;
            var fileName = tempID.ToString(); //current by-pass for name
            var path = Path.Combine(Server.MapPath("~/Content/Report/"), fileName);
            files.ElementAt(1).SaveAs(path);

            db.Configuration.ValidateOnSaveEnabled = true;
            return RedirectToAction("Index");
        }

Hopefully you may notice what I’m missing.

Answer 1

I’ve altered my Create method, and this is what I’ve come up with. Seems to work fine, but…

if (files.ElementAt(1) != null && files.ElementAt(1).ContentLength > 0)
{
    using (MemoryStream ms1 = new MemoryStream())
    {
        files.ElementAt(1).InputStream.CopyTo(ms1);
        report.Template = ms1.GetBuffer();
    }

}
else // this part of code did the trick, although not sure how good it is in practice
{
    return View(report);
}