Creating drag drop zone from files in NSView

Hello, 

I have made a program mostly in C and are now trying to make an interface in Cocoa. I want a drag and drop zone in the interface for files and have been struggling to get this to work. I think, mainly because I'm new to Cocoa and that most examples I have found so far is for images, not files. 

I have created an NSView in my interface and a class called dropZone, where I have the following code so far:

#import "dropZone.h"

@implementation dropZone

- (void)drawRect:(NSRect)rect

{

[self registerForDraggedTypes:[NSArray arrayWithObjects:NSFilenamesPboardType, nil]];

// [stringForType : NSFilenamesPboardType]

// [self dragFile:nil fromRect: rect slideBack: false event: nil];

NSRect bounds = [self bounds];

[[NSColor grayColor] set];

[NSBezierPath fillRect:bounds];

}

-(IBAction)getPath:(id)sender{

[textField setStringValue: @"Hello"];

}

@end

What's missing here to be able to complete the operation? What I'm going for here initially is getting the file path. Later on I'd like to restrict the file types that is accepted as well. 

Thanks.

Edit: didn't find any code tags, sorry.