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

问题

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?

回答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);

回答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.

回答3:

You can try by calling the subit from java script by appeding the parameters to the action example document.forms[0].action="photoprocess.asp?="+

and then submit

来源：https://stackoverflow.com/questions/11106784/form-post-with-enctype-multipart-form-data-causing-parameters-to-not-get-pas