Question

I am using DataAnnotationsExtensions from http://dataannotationsextensions.org/

with an example from here http://weblogs.asp.net/srkirkland/archive/2011/02/23/introducing-data-annotations-extensions.aspx

Controller Code

    public ActionResult Create(Dog dog, HttpPostedFileBase Picture)
    {
        Regex rgx = new Regex(@"^.*\.(jpg|gif|jpeg|png)$");
        Match m = rgx.Match(Picture.FileName);

        if (rgx.IsMatch(Picture.FileName))
            {
                if (ModelState.IsValid)
                {

Model Code

[FileExtensions("png|jpg|jpeg|gif", ErrorMessage = "Only jpg jpeg gif or png files allowed")]
        public string Picture { get; set; }

and the razor code

@Html.TextBoxFor(model => model.Picture, new { type = "file" })
@Html.ValidationMessageFor(model => model.Picture)

Everything I do it fails everytime at

if (ModelState.IsValid)

If I remove the FileExtensions Annotation it works fine but then I no longer have the ability to block file types that I dont want.

I have gone as far as to check the code for the data annotations extentions located here
https://github.com/srkirkland/DataAnnotationsExtensions/blob/master/DataAnnotationsExtensions/FileExtensionsAttribute.cs

and I still cant seem to find out where the problem is.

Answer 1

I believe that the model binder is getting confused with a property named ‘Picture’ on your model and a HttpPostedFileBase parameter named ‘Picture’ as well.

If you update your HttpPostedFileBase parameter to something other than ‘Picture’, the model binder should behave normally. Example:

public ActionResult Create(Dog dog, HttpPostedFileBase UploadedPicture)