objective c - Unable to show child view (iOS view container) -

in ios application, have main view controller 3 buttons, work tab bar: when click 1 of buttons, new view controller invoked. tried implement via container view containers, tried following guide (http://www.thinkandbuild.it/working-with-custom-container-view-controllers/) , invoke presentdetailcontroller method in viewdidload of main controller.

actually, no views showed: can me figuring out why? thanks.

viewcontroller.h

#import <uikit/uikit.h>  @interface viewcontroller : uiviewcontroller  @property (weak, nonatomic) iboutlet uibutton *btnone; @property (weak, nonatomic) iboutlet uibutton *btntwo; @property (weak, nonatomic) iboutlet uibutton *btnthree; @property (weak, nonatomic) iboutlet uiview *detailview;  - (ibaction)click:(id)sender;  @end 

viewcontroller.m

#import "viewcontroller.h" #import "firstviewcontroller.h"  @interface viewcontroller () @property uiviewcontroller  *currentdetailviewcontroller; @end  @implementation viewcontroller @synthesize btnone, btntwo, btnthree;  - (void)viewdidload {     [super viewdidload];     // additional setup after loading view, typically nib. firstviewcontroller *fvc = [[firstviewcontroller alloc]initwithstring:@"i'm first controller!"];      [self presentdetailcontroller:fvc]; }  - (void)didreceivememorywarning {     [super didreceivememorywarning];     // dispose of resources can recreated. } - (ibaction)click:(id)sender {     // button selection stuff      [self adddetailcontroller:sender]; }  - (void)presentdetailcontroller:(uiviewcontroller*)detailvc{      //0. remove current detail view controller showed     if(self.currentdetailviewcontroller){         [self removecurrentdetailviewcontroller];     }      //1. add detail controller child of container     [self addchildviewcontroller:detailvc];      //2. define detail controller's view size     detailvc.view.frame = [self framefordetailcontroller];      //3. add detail controller's view container's detail view , save reference detail view controller     [self.detailview addsubview:detailvc.view];     self.currentdetailviewcontroller = detailvc;      //4. complete add flow calling function didmovetoparentviewcontroller     [detailvc didmovetoparentviewcontroller:self];  }   - (void)removecurrentdetailviewcontroller{      //1. call willmovetoparentviewcontroller nil     //   last method detailviewcontroller can perform operations before neing removed     [self.currentdetailviewcontroller willmovetoparentviewcontroller:nil];      //2. remove detailviewcontroller's view container     [self.currentdetailviewcontroller.view removefromsuperview];      //3. update hierarchy"     //   automatically method didmovetoparentviewcontroller: called on detailviewcontroller)     [self.currentdetailviewcontroller removefromparentviewcontroller]; }  - (cgrect)framefordetailcontroller{     // newframe's height should currentframe's height minus buttons' height      cgrect detailframe = cgrectmake(0, 0, self.detailview.bounds.size.width, self.detailview.bounds.size.height-self.btnone.frame.size.height);     return detailframe; }  - (void)adddetailcontroller:(id)sender {     firstviewcontroller *detailvc = [[firstviewcontroller alloc]initwithstring:@"first button clicked"];      [self presentdetailcontroller:detailvc];  }     @end 

firstviewcontroller.h

#import <uikit/uikit.h> @class viewcontroller;  @interface firstviewcontroller : uiviewcontroller @property (weak, nonatomic) iboutlet uilabel *label; @property (weak, nonatomic) iboutlet uibutton *btnone; @property (weak, nonatomic) iboutlet uibutton *btntwo; @property (weak, nonatomic) iboutlet uibutton *btnthree;   - (id)initwithstring:(nsstring*)string;  @end 

firstviewcontroller.m

#import "firstviewcontroller.h"  @interface firstviewcontroller (){     nsstring *text; } @end  @implementation firstviewcontroller  - (id)initwithstring:(nsstring*)string {     self = [super init];      if(self){         text = string;     }      return self; }  - (void)viewdidload {     [super viewdidload];      self.label.text = text;  }   @end 

as part of creating firstviewcontroller, calling [super init] produces bare uiviewcontroller. diagram, seems if want load firstviewcontroller storyboard instead.

i suggest sequence create controller using instantiateviewcontrollerwithidentifier:, set string property in controller want use label, , assign string label when controller's view loads.