Extra parameter is coming with a POST - html

Question

My model is this a Movie class with this metadata:
[MetadataType(typeof(MovieMetadata))]
public partial class Movie
{
}
class MovieMetadata
{
[ScaffoldColumn(false)]
public int id { get; set; }
[Required(ErrorMessage = "Title is required")]]
[StringLength(70, ErrorMessage = "Title must have a lenght less than 70")]
public string title { get; set; }
[Required(ErrorMessage = "The realese date of the movie is required")]
public DateTime releaseDate { get; set; }
public string storyline { get; set; }
public Binary poster { get; set; }
[ScaffoldColumn(false)]
public Binary trailer { get; set; }
}
My Create View has this code inside:
#using (Html.BeginForm(null, null, FormMethod.Post, new { id = "createForm", enctype = "multipart/form-data" }))
{
#Html.AntiForgeryToken()
#Html.ValidationSummary(true)
<div class="gallMemberBox">
<div class="rightFormContent">
<div>
#Html.LabelFor(model => model.title)
#Html.EditorFor(model => model.title)
#Html.ValidationMessageFor(model => model.title)
</div>
<div>
#Html.LabelFor(model => model.releaseDate)
#Html.EditorFor(model => model.releaseDate)
#Html.ValidationMessageFor(model => model.releaseDate)
</div>
<div>
#Html.Label("Poster")
<input name="poster" value="C:" id="poster" type="file" />
</div>
<div>
#Html.Label("Trailer")
#* #Html.TextBox("trailer", "", new { type = "file", id="trailer" })*#
<input name="trailer" value="" id="trailer" type="file" />
</div>
<div>
#Html.LabelFor(model => model.storyline)
#Html.TextAreaFor(model => model.storyline, new{id="storyline"})
</div>
<div>
#Html.Label("Directors")
<select class="chosen-select" multiple="" data-placeholder="Select directors">
#for(int i = 0; i < directors.Count; i ++)
{
<option value="#i">#directors[i].name</option>
}
</select>
</div>
<div>
#Html.Label("Actors")
<select class="chosen-select" multiple="" data-placeholder="Select actors of the Screen">
#for(int i = 0; i < actors.Count; i ++)
{
<option value="#i">#actors[i].name</option>
}
</select>
</div>
<div>
#Html.Label("Writers")
<select class="chosen-select" multiple="" data-placeholder="Select writers of the Film">
#for(int i = 0; i < writers.Count; i ++)
{
<option value="#i">#writers[i].name</option>
}
</select>
</div>
<input type="submit" value="Create" />
</div>
}
I just filled title and releaseDate and click on submit(Create), after that in my ModelState I have three parameters, title, releaseDate and storyline(I never put some value on this one, and the value is an empty string. On the others fields I never put a value and they do not come with that POST. Why? And how to fix this?
public ActionResult Create([Bind(Exclude = "poster, trailer")]Movie movie, HttpPostedFileBase poster, HttpPostedFileBase trailer)
{

Answer 1

Your field storyline will already be available by the id and name "storyline as this is created like by MVC.
Remove the "id" part, or use "#id = ...".

Answer 2

You can write:
<div>
Storyline
#Html.TextAreaFor(model => model.storyline)
</div>