ios - UICollectionViewLayout. Where are all my items? -

when implement uicollectionview without custom layout object, 16 of reusable cells appear. is, have 1 section 16 items in section. when create custom layout object, 1 cell appears. if change # of sections 5, 5 cells appear. why collectionview draw sections when using layout object, , items when using default grid???? missing something?

i subclass uicollectionviewlayout here:

 static nsstring * const kpadlayouttype = @"gridpads";   - (id)initwithcoder:(nscoder *)adecoder  {      self = [super initwithcoder:adecoder];      if(self) {          [self setup];      }      return self;  }   - (void)setup  {      self.iteminsets = uiedgeinsetsmake(22.0f, 22.0f, 13.0f, 22.0f);      self.itemsize = cgsizemake(125.0f, 125.0f);      self.interitemspacingy = 12.0f;      self.numberofcolumns = 4;  }   # pragma mark _____layout   - (void)preparelayout  {      nsmutabledictionary *newlayoutinfo = [nsmutabledictionary dictionary];      nsmutabledictionary *celllayoutinfo = [nsmutabledictionary dictionary];       nsinteger sectioncount = [self.collectionview numberofsections];      nsindexpath *indexpath = [nsindexpath indexpathforitem:0 insection:0];       for(nsinteger section = 0; section < sectioncount; section++) {          nsinteger itemcount = [self.collectionview numberofitemsinsection:section];           for(nsinteger item = 0; item < itemcount; item++) {              indexpath = [nsindexpath indexpathforitem:item insection:section];               uicollectionviewlayoutattributes *itemattributes = [uicollectionviewlayoutattributes layoutattributesforcellwithindexpath:indexpath];              itemattributes.frame = [self frameforpadatindexpath:indexpath];               celllayoutinfo[indexpath] = itemattributes;          }      }      newlayoutinfo[kpadlayouttype] = celllayoutinfo;      self.layoutinfo = newlayoutinfo;  }   - (cgsize)collectionviewcontentsize  {      return self.collectionview.frame.size;  }   - (nsarray *) layoutattributesforelementsinrect:(cgrect)rect  {      nsmutablearray *allattributes = [nsmutablearray arraywithcapacity:self.layoutinfo.count];       [self.layoutinfo enumeratekeysandobjectsusingblock:^(nsstring *elementidentifier,                                                      nsdictionary *elementsinfo,                                                      bool *stop) {          [elementsinfo enumeratekeysandobjectsusingblock:^(nsindexpath *indexpath,                                                       uicollectionviewlayoutattributes *attributes,                                                       bool *innerstop) {              if(cgrectintersectsrect(rect, attributes.frame)) {                  [allattributes addobject:attributes];              }          }];      }];      return allattributes;  }   - (uicollectionviewlayoutattributes *)layoutattributesforitematindexpath:(nsindexpath *)indexpath  {      return self.layoutinfo[kpadlayouttype][indexpath];  }   # pragma mark _____private   - (cgrect)frameforpadatindexpath:(nsindexpath *)indexpath  {      nsinteger row = indexpath.section/ self.numberofcolumns;      nsinteger column = indexpath.section % self.numberofcolumns;       cgfloat spacingx = self.collectionview.bounds.size.width - self.iteminsets.left - self.iteminsets.right - (self.numberofcolumns * self.itemsize.width);       if(self.numberofcolumns > 1) spacingx = spacingx / (self.numberofcolumns - 1);       cgfloat originx = floorf(self.iteminsets.left + (self.itemsize.width + spacingx) * column);       cgfloat originy = floor(self.iteminsets.top + (self.itemsize.height + self.interitemspacingy) * row);       return cgrectmake(originx, originy, self.itemsize.width, self.itemsize.height);  }  

i invalidate layout in each setter.

i using collectionview within uiviewcontroller in viewcontroller register cell class use in viewdidload , setup following:

 # pragma mark - uicollectionviewdatasource   - (nsinteger)collectionview:(uicollectionview *)collectionview numberofitemsinsection:(nsinteger)section  {      return 16;  }   - (nsinteger)numberofsectionsincollectionview:(uicollectionview *)collectionview  {      return 1;  }   - (uicollectionviewcell *)collectionview:(uicollectionview *)collectionview cellforitematindexpath:(nsindexpath *)indexpath  {      pad *mypad = [collectionview dequeuereusablecellwithreuseidentifier:kpadlayouttype forindexpath:indexpath];      return mypad;  } 

it seems me frameforpadatindexpath: method return same frame each item within same section , varies position section.

changing

 nsinteger row = indexpath.section/ self.numberofcolumns;  nsinteger column = indexpath.section % self.numberofcolumns; 

into

 nsinteger row = indexpath.item/ self.numberofcolumns;  nsinteger column = indexpath.item % self.numberofcolumns; 

might give better results.