IOS设计模式:单例以及单例传值

单例模式代码如下：

#import "TRclas.h"

static TRclas *share = nil;

@implementation TRclas

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

.h文件代码

#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;
    
}