ios - Unexpected delay when presenting UITableViewController -

i have custom uitableviewcell in uitableviewcontroller, when controller tries dequeue custom cell, take long time (like 2000ms).

this line of code causes problem

kidslisttableviewcell *cell = [tableview dequeuereusablecellwithidentifier:@"kidsreuseidentifier" forindexpath:indexpath]; 

the kidslisttableviewcell custom cell, includes couple of uibuttons, uilabels show information. , 2 delegate methods. shouldn't slow render view. way, of information in custom cell static.

the full code of uitableviewcontroller. put custom view , regular view in different sections , don't think causes problem.

#import "kiddetailtableviewcontroller.h" #import "kiddetailheadertableviewcell.h" #import <assetslibrary/assetslibrary.h> #import "helper.h"  @interface kiddetailtableviewcontroller () <kiddetailheadercelldelegate>  @end  @implementation kiddetailtableviewcontroller {     kiddetailheadertableviewcell *headercell; }  - (void)viewdidload {     [super viewdidload];      [self.tableview registernib:[uinib nibwithnibname:@"kiddetailheader" bundle:nil] forcellreuseidentifier:@"kiddetail"];      [self.tableview registerclass:[uitableviewcell class] forcellreuseidentifier:@"detailcell"];       self.tableview.showsverticalscrollindicator = no;  }   - (void)viewwillappear:(bool)animated {     [super viewwillappear:animated];  }  - (void)didreceivememorywarning {     [super didreceivememorywarning];     // dispose of resources can recreated. }  #pragma mark - table view data source  - (nsinteger)numberofsectionsintableview:(uitableview *)tableview {     // return number of sections.     return 2; }  - (nsinteger)tableview:(uitableview *)tableview numberofrowsinsection:(nsinteger)section {      switch (section) {         case 0:             return 1;             break;          default:             return 10;             break;     } }  - (uitableviewcell *)tableview:(uitableview *)tableview cellforrowatindexpath:(nsindexpath *)indexpath {      if (indexpath.section == 0) {         if (!headercell) {               headercell = [tableview dequeuereusablecellwithidentifier:@"kiddetail"];              headercell.delegate = self;               // keep background color cell when select.             headercell.selectionstyle = uitableviewcellselectionstylenone;              headercell.nicknamelabel.text = _kidneedstoshow.nickname;              nsstring *kidfullname = [nsstring stringwithformat:@"%@ %@ %@", _kidneedstoshow.firstname, _kidneedstoshow.midname, _kidneedstoshow.lastname];              kidfullname ? (headercell.fullnamelabel.text = @"") : (headercell.fullnamelabel.text = kidfullname);               // set thumb image or use default             // if there isn't image, use default.             alassetslibrary *library = [alassetslibrary new];             [library assetforurl:_kidneedstoshow.photourl resultblock:^(alasset *asset) {                 [headercell.avatarimage setimage:[uiimage imagewithcgimage:[[asset defaultrepresentation] fullresolutionimage]]];             } failureblock:nil];             return headercell;         }         else return headercell;     }      uitableviewcell *cell = [tableview dequeuereusablecellwithidentifier:@"detailcell" forindexpath:indexpath];     return cell; }  - (cgfloat)tableview:(uitableview *)tableview heightforrowatindexpath:(nsindexpath *)indexpath {     if (indexpath.section == 0) {         return 290;     }     else return 60; }  - (cgfloat)tableview:(uitableview *)tableview estimatedheightforrowatindexpath:(nsindexpath *)indexpath {     if (indexpath.section == 0) {         return 290;     }     else return 60; }  - (void)didclickleftbutton:(uibutton *)leftbutton {     [self dismissviewcontrolleranimated:yes completion:nil]; }  @end 

i tried put dequeuereusablecellwithidentifier different thread, apparently wouldn't work.

update: kiddetailheadertableviewcell.m

- (void)awakefromnib {     // initialization code     [_avatarimage.layer setcornerradius:_avatarimage.frame.size.width / 2];     [_avatarimage.layer setbordercolor:[uicolor whitecolor].cgcolor];     [_avatarimage.layer setborderwidth:1.0];     [_avatarimage setclipstobounds:yes];  }  - (ibaction)leftbuttonclicked:(uibutton *)sender {     if (self.delegate && [self.delegate respondstoselector:@selector(didclickleftbutton:)]) {         [self.delegate didclickleftbutton:sender];     } } - (ibaction)rightbuttonclicked:(uibutton *)sender {     if (self.delegate && [self.delegate respondstoselector:@selector(didclickrightbutton:)]) {         [self.delegate didclickrightbutton:sender];     } } 

kiddetailheadertableviewcell.h

@protocol kiddetailheadercelldelegate <nsobject>  @optional - (void)didclickleftbutton:(uibutton *)leftbutton; - (void)didclickrightbutton:(uibutton *)rightbutton;  @end  @interface kiddetailheadertableviewcell : uitableviewcell  @property (weak) id<kiddetailheadercelldelegate> delegate;  @property (weak, nonatomic) iboutlet uilabel *fullnamelabel; @property (weak, nonatomic) iboutlet uiimageview *avatarimage; @property (weak, nonatomic) iboutlet uilabel *nicknamelabel;  @property (weak, nonatomic) iboutlet uilabel *agetext; @property (weak, nonatomic) iboutlet uilabel *agelabel;  @property (weak, nonatomic) iboutlet uilabel *momentsstatistics; @property (weak, nonatomic) iboutlet uilabel *momentslabel;  @property (weak, nonatomic) iboutlet uibutton *rightbutton; @property (weak, nonatomic) iboutlet uibutton *leftbutton;  @end 

update 2: screenshot of instrument

the code set height of cell. have 2 sections, first section used header, height 290.

- (cgfloat)tableview:(uitableview *)tableview heightforrowatindexpath:(nsindexpath *)indexpath {     if (indexpath.section == 0) {         return 290;     }     else return 60; } 

one of friend pointed out problem caused custom font (yes! used custom font in custom view). still not sure why causes problem (the font named 'hero'), hope else.