ios - The value get by delegate method is been clear? -

in tableviewcontrollera.h declare delegate ,and in tableviewcontrollera.m implement method when click cell of tableview, pass value b, , execute perfromseguewithidentifier jump tableviewcontrollb,in tableviewcontrollb.m getting method called, , value, after viewdidload() method call, value become nil. please me solve problem.by way , property of value strong,nonatomic.

dtzhometableviewcontroller.h    #import <uikit/uikit.h>    #import "passdata.h"  @protocol passdatadelegate     -(void)passdata:(passdata*) datatoprogram;    @end    @interface dtzhometableviewcontroller :     uitableviewcontroller<uitableviewdelegate,uitableviewdatasource>    @property(assign,nonatomic) id<passdatadelegate> datadelegate;    @end    passdata user-defined class        dtzhometableviewcontroller.m  -(void)tableview:(uitableview *)tableview didselectrowatindexpath:(nsindexpath *)indexpath    {       programtableviewcontroller *programviewcontroller=    [[programtableviewcontroller alloc]init];        self.datadelegate=programviewcontroller;;                 passdata *jump=[[passdata alloc]init];      jump.livingstatus=yes;      jump.role=0;      jump.index=indexpath.row;      jump.curonlinenum=305605;       [self.datadelegate passdata:jump];       [self performseguewithidentifier:@"showselectedprogram" sender:self];    }    programtableviewcontroller.h  #import <uikit/uikit.h>  #import "dtzhometableviewcontroller.h"    @interface programtableviewcontroller :   uitableviewcontroller<passdatadelegate,uitableviewdatasource,uitableviewdelegate>    @property(strong,nonatomic) passdata * datafromhome;    @end       programtableviewcontroller.m    @implementation programtableviewcontroller  - (void)viewdidload {        [super viewdidload];        nslog(@"view did load%@",self.datafromhome); // log :null  }  - (void) passdata:(passdata *)datatoprogram  {            self.datafromhome=datatoprogram;       }  @end

delegation isn't proper way pass data segued view controller. instead, want pass data in prepareforsegue:sender:

remove protocol , delegate.

add properties programtableviewcontroller data want pass.

@property (nonatomic, assign) bool livingstatus; @property (nonatomic, assign) nsinteger role; @property (nonatomic, assign) nsinteger row; @property (nonatomic, assign) nsinteger curonlinenum; 

in prepareforsegue:sender:, set programtableviewcontroller's passed properties values associated selected row:

- (void)prepareforsegue:(uistoryboardsegue *)segue sender:(id)__unused sender {     if ([[segue identifier] isequaltostring:@"showdetail"])     {         nsindexpath *indexpath = [self.tableview indexpathforselectedrow];         programtableviewcontroller *controller = (programtableviewcontroller *)[segue destinationviewcontroller];         controller.livingstatus = yes;         controller.role = 0;         controller.row = indexpath.row;         controller.curonlinenum = 305605;     } } 

you shouldn't allocate , init programtableviewcontroller in tableview:didselectrowatindexpath:. segue instantiate destination view controller you.

you don't need have tableview:didselectrowatindexpath: method. can create push segue tableviewcell programtableviewcontroller, right within storyboard. give segue identifier (such "showdetail"). in prepareforsegue, assign values, explained.

when tap on row, segue create programtableviewcontroller, set parameters, , present you.