Form Post with enctype = "multipart/form-data" causing parameters to not get passed

Question

In an ASP.NET MVC 3 (Razor) project i 'm trying to upload a picture: the relevant part of the view:

@using (@Html.BeginForm( new {enctype = "multipart/form-data" }))
{
    <text>Select a file </text>    
    <input type="file" name="file" />     
    <input type="submit" value="Upload" />        
}

stating explicitly the enctype parameter is "responsible" for stripping off the parameter part. For example, if the URL (opening the view) was the following:

mydomain/Controller/Action/id?parameter1=somevalue1

the BeginForm-statement in the form above would give (posting back) the following:

mydomain/Controller/Action/id

thus stripping off the part: ?parameter1=somevalue1 which is needed!

How do i take care of this?

Solution 1

Since you're already posting data to the server I'd put the required parameter information in the form as hidden fields.

Asking the question "Can I send this collection of information to this URL without needing to populate other collections?"

With the querystring method the answer is no. I'd put it as a hidden field.

@Html.Hidden("SomeParameter", SomeValue);

Solution 2

Digging a little bit deeper i discovered that i can do:

@using (@Html.BeginForm(new{parameter1= Request["parameter1"]},  new {enctype = "multipart/form-data" }))
{
    <text>Select a file </text>    
    <input type="file" name="file" />     
    <input type="submit" value="Upload" />        
}

Notice how the Html.BeginForm differs from the initial.

Comments

[Savvas Sopiadis]

What should be preferred: your method or the way i 'm suggesting?

[Jamie Dixon]

Personally I prefer this method since you can take a collection of data and post it to your action method knowing that you'll get an expected result. With the querystring method, you can't be confident that your server post will be enough because a value in the querystring collection is also required. If this was a RESTful service you'd also want all the required data in the post.