ios - Self sizing cell just doesn't work for me -

i tried follow wwcd 2014 session 226, introduced way realize self sizing cells in ios 8 using auto layout, , doesn't work should.


hhtableviewcell.h

#import <uikit/uikit.h> @interface hhtableviewcell : uitableviewcell @property (strong, nonatomic)uilabel *title;  @end 

hhtableviewcell.m

#import "hhtableviewcell.h"  @implementation hhtableviewcell  @synthesize title = _title;  - (instancetype)initwithstyle:(uitableviewcellstyle)style reuseidentifier:(nsstring *)reuseidentifier {     self = [super initwithstyle:style reuseidentifier:reuseidentifier];     if (self) {         // configure control(s)  #pragma mark -- title lable         _title = [[uilabel alloc] initwithframe:cgrectinset(self.bounds, 15.0, 0.0)];         _title.font = [uifont preferredfontfortextstyle:uifonttextstyleheadline];         _title.numberoflines = 0;         [self.contentview addsubview:_title];   #pragma mark -- constraints         nsmutablearray *constraints = [[nsmutablearray alloc]init];         uiview *contentview = self.contentview;          [constraints addobject:[nslayoutconstraint                                 constraintwithitem:_title                                 attribute:nslayoutattributefirstbaseline                                 relatedby:nslayoutrelationequal                                 toitem:contentview                                 attribute:nslayoutattributetop                                 multiplier:1.8                                 constant:3.0]];          [constraints addobject:[nslayoutconstraint                                 constraintwithitem:_title                                 attribute:nslayoutattributefirstbaseline                                 relatedby:nslayoutrelationequal                                 toitem:contentview                                 attribute:nslayoutattributetop                                 multiplier:1.8                                 constant:3.0]];          [constraints addobject:[nslayoutconstraint                                 constraintwithitem:_title                                 attribute:nslayoutattributefirstbaseline                                 relatedby:nslayoutrelationequal                                 toitem:contentview                                 attribute:nslayoutattributetop                                 multiplier:1.8                                 constant:3.0]];          [constraints addobject:[nslayoutconstraint                                 constraintwithitem:contentview                                 attribute:nslayoutattributeheight                                 relatedby:nslayoutrelationgreaterthanorequal                                 toitem:nil                                 attribute:0                                 multiplier:1.0                                 constant:44.0]];          [constraints addobjectsfromarray:[nslayoutconstraint                                           constraintswithvisualformat:@"h:|-15-[_title]-15-|"                                           options:0                                           metrics:nil                                           views:nsdictionaryofvariablebindings(_title)]];            [self.contentview addconstraints:constraints];     }     return self;  }  @end 

mmtableviewcontroller.h

#import <uikit/uikit.h>  @interface mmtableviewcontroller : uitableviewcontroller  @end 

mmtableviewcontroller.m

#import "mmtableviewcontroller.h" #import "hhtableviewcell.h"  @interface mmtableviewcontroller ()  @end  @implementation mmtableviewcontroller  - (void)viewdidload {     [super viewdidload];      [self.tableview registerclass:[hhtableviewcell class] forcellreuseidentifier:@"hicell"];     [self.tableview registerclass:[hhtableviewcell class] forcellreuseidentifier:@"hcell"];      self.tableview.estimatedrowheight = 44.0;     self.tableview.rowheight = uitableviewautomaticdimension;      // uncomment following line preserve selection between presentations.     // self.clearsselectiononviewwillappear = no;      // uncomment following line display edit button in navigation bar view controller.     // self.navigationitem.rightbarbuttonitem = self.editbuttonitem; }  - (void)didreceivememorywarning {     [super didreceivememorywarning];     // dispose of resources can recreated. }  #pragma mark - table view data source  - (nsinteger)numberofsectionsintableview:(uitableview *)tableview { #warning potentially incomplete method implementation.     // return number of sections.     return 1; }  - (nsinteger)tableview:(uitableview *)tableview numberofrowsinsection:(nsinteger)section { #warning incomplete method implementation.     // return number of rows in section.     return 10; }   - (uitableviewcell *)tableview:(uitableview *)tableview cellforrowatindexpath:(nsindexpath *)indexpath {     static nsstring *cellidentifier = @"hicell";      hhtableviewcell *cell = [tableview dequeuereusablecellwithidentifier:cellidentifier forindexpath:indexpath];      cell.title.text = @"hello apple. hello apple. hello apple. hello apple. hello apple. hello apple. hello apple. hello apple. hello apple. hello apple. hello apple. hello apple. hello apple. ";      // configure cell...     nslog(cell.title.text);      return cell; }   @end 

cell of fixed height , wrapping 2 lines of text. looks this:

hello apple. hello apple. hello apple. hello
aplle. hello apple. hello apple. hello apple...


constraints , subviews added programatically. simulator running ios 8.3 in xcode 6.3.1.

for uilabel work constraints, looking @ apple's documentation, think need set preferredmaxlayoutwidth property:

this property affects size of label when layout constraints applied it. during layout, if text extends beyond width specified property, additional text flowed 1 or more new lines, thereby increasing height of label.

however, unless want specific cell customization, can use default uitableviewcell, , set numberoflines = 0 on provided titlelabel. work uitableviewautomaticdimension, although i've tested in conjunction heightforrowatindexpath:.

update:

from i've learned, need set estimatedrowheight in viewdidload (the value doesn't needs accurate/important seems).

here working example using default uitableviewcells: