IOS设计模式:单例以及单例传值

#import "TRclas.h"

static TRclas *share = nil;

@implementation TRclas

+(TRclas *)defaultNum{

if (!share)
{
share=[[TRclas alloc]init];
}
return share;
}
@end

#import <Foundation/Foundation.h>

@interface TRclas : NSObject

@property(nonatomic ,assign)NSUInteger num;

+(TRclas *)defaultNum;

@end

#import "TRAViewController.h"
#import "TRBViewController.h"
#import "TRclas.h"

@interface TRAViewController ()
@property (weak, nonatomic) IBOutlet UIStepper *stepper;
@property(nonatomic,strong)TRBViewController *svc;

@end

@implementation TRAViewController

- (IBAction)btnA:(UIButton *)sender {

[TRclas defaultNum].num = (int)self.stepper.value;

self.svc.modalTransitionStyle=UIModalTransitionStyleFlipHorizontal;

[self presentViewController:self.svc animated:YES completion:nil];
}

-(void)viewWillAppear:(BOOL)animated{

[super viewWillAppear:animated];

self.stepper.value=[TRclas defaultNum].num;

}