ios - Searchbar subview in UICollectionView delegate -

i trying add searchbar collectionview disappears when user swipes down collectionview view cell , images.

i able add searchbar without problems, when try hook delegate, crash:

 -[uicollectionreusableview searchbar]: unrecognized selector sent instance 0x7fb30bc627f0 *** terminating app due uncaught exception 'nsinvalidargumentexception', reason: '-[uicollectionreusableview searchbar]: unrecognized selector sent instance 0x7fb30bc627f0' 

the interface first view, main view's class looks like:

@interface okphotogalleryviewcontroller ()

here code viewdidload method:

[self.flickrcollectionview registernib:[uinib nibwithnibname:nsstringfromclass([oksearchbarphotogalleryviewcell class]) bundle:nil] forsupplementaryviewofkind:uicollectionelementkindsectionheader withreuseidentifier:@"searchbar"];      uisearchbar *searchbar;     [self.flickrcollectionview addsubview:searchbar]; 

and here viewforsupplementaryelementofkind method required:

- (uicollectionreusableview *)collectionview:(uicollectionview *)collectionview viewforsupplementaryelementofkind:(nsstring *)kind atindexpath:(nsindexpath *)indexpath{     static nsstring *searchbaridentifier = @"searchbar";     oksearchbarphotogalleryviewcell *collectionviewsearchbar = (oksearchbarphotogalleryviewcell *)[collectionview dequeuereusablesupplementaryviewofkind:uicollectionelementkindsectionheader withreuseidentifier:searchbaridentifier forindexpath:indexpath];      collectionviewsearchbar.searchbar.delegate = self;      return collectionviewsearchbar; } 

where application crashes on line

collectionviewsearchbar.searchbar.delegate = self; 

and class' header instantiating , adding subview inside of uicollectionview looks like:

@interface oksearchbarphotogalleryviewcell : uicollectionreusableview  @property (nonatomic, strong) iboutlet uisearchbar *searchbar;  @end 

i've tried changing class names, because @ first searchbar.searchbar.delegate = self, , thought could've caused problems, didn't help. tried hook delegate searchbar in oksearchbarphotogalleryviewcell, still received same crash.

i solved last night creating searchbar, putting in right place, hooking delegate , adding on subview. works charm , searchbar delegate methods sends me messages correctly.

    - (uicollectionreusableview *)collectionview:(uicollectionview *)collectionview viewforsupplementaryelementofkind:(nsstring *)kind atindexpath:(nsindexpath *)indexpath {     static nsstring *searchbaridentifier = @"searchbar";     oksearchbarphotogalleryviewcell *collectionviewsearchbar = (oksearchbarphotogalleryviewcell *)[collectionview dequeuereusablesupplementaryviewofkind:uicollectionelementkindsectionheader withreuseidentifier:searchbaridentifier forindexpath:indexpath];      uisearchbar *searchbar = [[uisearchbar alloc] initwithframe:cgrectmake(0, 0, cgrectgetwidth(collectionview.frame), 44)];     searchbar.autocorrectiontype = uitextautocorrectiontypeno;     searchbar.delegate = self;      [collectionviewsearchbar addsubview:searchbar];     return collectionviewsearchbar; }