Gravity Forms Dynamically Populate Post/Page Category - php

Question

I would like to be able to use the same form on several pages, and know which page a submitted form came from. For a long list of reasons, I need to do that based on category.
I found code to add categories to pages, works great.
But I can't figure out how to get Gravity Forms to dynamically populate a field with the category.
I've selected "Allow field to be populated dynamically" on the form, I've set the parameter name to "pagecategory"
Here's what I've got - it does nothing:
//Get Page Category - For Demo Form
add_filter("gform_field_value_pagecategory", "populate_pagecategory");
function populate_pagecategory($value){
global $post;
$value = get_the_category( $post->ID,'metakeyname',true);
return $value;
}

Answer 1

get_the_category() actually returns an array of all category that is assigned to that post. The code below works for me to fetch the name of first category only.
//Get Page Category - For Demo Form
add_filter("gform_field_value_pagecategory", "populate_pagecategory");
function populate_pagecategory($value){
global $post;
$categories = get_the_category( $post->ID,'metakeyname',true);
$value = $categories[0]->cat_name;
return $value;
}

Answer 2

I'm a bit surprised this type of need/question isn't more prevalent. I had to do this same thing, but for a custom taxonomy. In case anyone lands here in need of how to do Mash's answer, but with a custom taxonomy, the following is working for me. My custom taxonomy is "services," which you can see replaces 'metakeyname' in Mash's answer.
//Get Page Custom Taxonomy - For Gravity Forms
add_filter("gform_field_value_pagecategory", "populate_pagecategory");
function populate_pagecategory($value){
global $post;
$terms = get_the_terms( $post->ID,'services',true);
$value = $terms[0]->name;
return $value;
}