Convert HttpPostedFileBase to byte[]

Null Pointer picture Null Pointer · Oct 21, 2011 · Viewed 108.3k times · Source

In my MVC application, I am using following code to upload a file.

MODEL

 public HttpPostedFileBase File { get; set; }

VIEW

@Html.TextBoxFor(m => m.File, new { type = "file" })

Everything working fine .. But I am trying to convert the result fiel to byte[] .How can i do this

CONTROLLER

 public ActionResult ManagePhotos(ManagePhotos model)
    {
        if (ModelState.IsValid)
        {
            byte[] image = model.File; //Its not working .How can convert this to byte array
        }
     }

Answer

Jon Skeet picture Jon Skeet · Oct 21, 2011

As Darin says, you can read from the input stream - but I'd avoid relying on all the data being available in a single go. If you're using .NET 4 this is simple:

MemoryStream target = new MemoryStream();
model.File.InputStream.CopyTo(target);
byte[] data = target.ToArray();

It's easy enough to write the equivalent of CopyTo in .NET 3.5 if you want. The important part is that you read from HttpPostedFileBase.InputStream.

For efficient purposes you could check whether the stream returned is already a MemoryStream:

byte[] data;
using (Stream inputStream = model.File.InputStream)
{
    MemoryStream memoryStream = inputStream as MemoryStream;
    if (memoryStream == null)
    {
        memoryStream = new MemoryStream();
        inputStream.CopyTo(memoryStream);
    }
    data = memoryStream.ToArray();
}