iphone - UILabel in custom cell will not increase height dynamically -

i've got custom cell contains 3 uilabels. last label contain text has embedded \n's data in cell listed 1 item per line. know number of lines needed , know each line needs 15 pixels high. code i've got change size of label here:

//set cell static nsstring *cellidentifier = @"cell"; customhistorycell *cell = (customhistorycell *)[tableview dequeuereusablecellwithidentifier:cellidentifier]; if (cell == nil) {     cell = [[[customhistorycell alloc] initwithframe:cgrectzero reuseidentifier:cellidentifier] autorelease]; } cell.probeinfo.linebreakmode = uilinebreakmodewordwrap; cell.probeinfo.numberoflines = 0; cell.probeinfo.text = theprobes; [cell.probeinfo setadjustsfontsizetofitwidth:yes]; cgrect newframe = cell.probeinfo.frame; newframe.size.height = nadditionallabelheight*15; cell.probeinfo.frame = newframe; 

theprobes contains text \n's , nadditionallabelheight contains number of lines. i've set background color grey can see if label correctly sized , doesn't change it's height. can see i'm doing wrong?

here's code custom cell .h file in case may help:

@interface customhistorycell : uitableviewcell {     uilabel *_stokername;     uilabel *_smokedatetime;     uilabel *_probeinfo;  } @property (nonatomic,retain) uilabel *stokername; @property (nonatomic,retain) uilabel *smokedatetime; @property (nonatomic,retain) uilabel *probeinfo;  @end 

and here's code custom cell .m file in case may help:

#import "customhistorycell.h"   @implementation customhistorycell  @synthesize stokername = _stokername; @synthesize smokedatetime = _smokedatetime; @synthesize probeinfo = _probeinfo;  - (id)initwithstyle:(uitableviewcellstyle)style     reuseidentifier:(nsstring *)reuseidentifier {     if (self = [super initwithstyle:style reuseidentifier:reuseidentifier])     {         // initialization code         self.stokername = [[uilabel alloc]init];         self.stokername.textalignment = uitextalignmentleft;         self.stokername.font = [uifont boldsystemfontofsize:20];         self.smokedatetime = [[uilabel alloc]init];         self.smokedatetime.textalignment = uitextalignmentleft;         self.smokedatetime.font = [uifont systemfontofsize:12];         self.probeinfo = [[uilabel alloc]init];         self.probeinfo.textalignment = uitextalignmentleft;         self.probeinfo.font = [uifont systemfontofsize:12];         self.probeinfo.backgroundcolor = [uicolor graycolor];         [self.contentview addsubview:self.stokername];         [self.contentview addsubview:self.smokedatetime];         [self.contentview addsubview:self.probeinfo];     }       return self; }  - (void)layoutsubviews {     [super layoutsubviews];     cgrect contentrect = self.contentview.bounds;     cgfloat boundsx = contentrect.origin.x;     cgrect frame;     frame= cgrectmake(boundsx+5,5, 300, 25);     self.stokername.frame = frame;     frame= cgrectmake(boundsx+5,30, 300, 15);     self.smokedatetime.frame = frame;     frame= cgrectmake(boundsx+5,45, 300, 15);     self.probeinfo.frame = frame; }  - (void)dealloc {     [super dealloc]; }  @end 

i figured out way handle this. override initwithstyle , passed in nadditionallabelheight variable , used set height of label.