ios - Large UICollectionViewCell disappear on scrolling -

i'm encountering same problem here large uicollectionviewcell (more twice of uicollectionview height apparently) disappear @ given scrolling offset , reappear after given scrolling offset also.

i've implemented @jonathancichon solution subclass uicollectionview , perform custom action on _visiblebounds (i know it's private api no matter, don't need submit on apple store)

here custom collection view :

#import "collectionview.h"  @interface uicollectionview ()  - (cgrect)_visiblebounds;  @end  @implementation collectionview  - (cgrect)_visiblebounds {     cgrect rect = [super _visiblebounds];     rect.size.height = [self heightoflargestvisiblecell];     return rect; }  - (cgfloat)heightoflargestvisiblecell {     // current screen height depending on orientation     cgfloat screensize = [self currentscreenheight];      cgfloat largestcell = 0;      nsarray *visiblecells = self.visiblecells;      // largest height between visiblecells     (uitableviewcell *c in visiblecells)     {         cgfloat h = c.frame.size.height;         largestcell = h > largestcell ? h : largestcell;     }      // return higher value between screen height , higher visible cell height     return max(largestcell, screensize); } 

this works, no more disappeared on scrolling still have problem : if perform reloaddata when scroll position in middle of large cell, disappear earlier ... i've noticed after reloading data, visiblecells return nil (in heightoflargestvisiblecell method), take screen height _visiblebounds since screen height < current visible cell height, 1 not displayed ...

someone faced issue ?

thx in advance

i got solution problem. store value calculated heightoflargestvisiblecell , return last value after reload data.

@interface collectionview : uicollectionview @property (nonatomic, assign) cgfloat lastlargestcellheight; @property (nonatomic, assign) bool shouldevallargestcellheight;  @end  @implementation collectionview  - (cgrect)_visiblebounds {     cgrect rect = [super _visiblebounds];     rect.size.height = [self heightoflargestvisiblecell];     return rect; }   - (cgfloat)heightoflargestvisiblecell {     if (self.shouldevallargestcellheight) {         // current screen height depending on orientation         cgfloat screensize = self.frame.size.height;          cgfloat largestcell = 0;          nsarray *visiblecells = self.visiblecells;          // largest height between visiblecells         (uitableviewcell *c in visiblecells)         {             cgfloat h = c.frame.size.height;             largestcell = h > largestcell ? h : largestcell;         }         //return higher value between screen height , higher visible cell height         self.lastlargestcellheight = max(largestcell, screensize);         self.shouldevallargestcellheight = no;     }     return self.lastlargestcellheight; }  - (void)reloaddata {     self.shouldevallargestcellheight = no;     [super reloaddata]; }  - (void)setcontentoffset:(cgpoint)contentoffset {     self.shouldevallargestcellheight = yes;     [super setcontentoffset:contentoffset]; }  @end