Block传值

#import <UIKit/UIKit.h>

//无参数
typedef void(^NoReferenceBlock)();
//一个参数
typedef void(^oneReferenceBlock)(NSString *str);
//多个参数
typedef void(^moreReferenceBlock)(NSString *str,NSString *str1);
@interface SecondViewController : UIViewController
@property (nonatomic, copy) NoReferenceBlock noReferenceBlock;
@property (nonatomic, copy) oneReferenceBlock oneReferenceBlock;
@property (nonatomic, copy) moreReferenceBlock moreReferenceBlock;

- (void)noReferenceBlock:(NoReferenceBlock)block;
- (void)oneReferenceBlock:(oneReferenceBlock)block;
- (void)moreReferenceBlock:(moreReferenceBlock)block;

+ (SecondViewController *)secondVC;
@end

#import "SecondViewController.h"

@interface SecondViewController ()

@end

@implementation SecondViewController
+ (SecondViewController *)secondVC{
    SecondViewController *vc = [[SecondViewController alloc]initWithNibName:@"SecondViewController" bundle:nil];
    return vc;
}
- (void)noReferenceBlock:(NoReferenceBlock)block{
    self.noReferenceBlock = block;
}
- (void)oneReferenceBlock:(oneReferenceBlock)block{
    self.oneReferenceBlock = block;
}
- (void)moreReferenceBlock:(moreReferenceBlock)block{
    self.moreReferenceBlock = block;
}
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
}
- (IBAction)noone:(UIButton *)sender {
    if (self.noReferenceBlock != nil) {
        self.noReferenceBlock();
    }
    [self.navigationController popViewControllerAnimated:YES];
}
- (IBAction)one:(UIButton *)sender {
    if (self.oneReferenceBlock != nil) {
        self.oneReferenceBlock(@"一个参数");
    }
    [self.navigationController popViewControllerAnimated:YES];
}
- (IBAction)two:(UIButton *)sender {
    if (self.moreReferenceBlock != nil) {
        self.moreReferenceBlock(@"参数1", @"参数2");
    }
    [self.navigationController popViewControllerAnimated:YES];

}

#import "ViewController.h"
#import "SecondViewController.h"
 SecondViewController *vc = [SecondViewController secondVC];
    vc.noReferenceBlock = ^{
        NSLog(@"没有参数");
    };
    vc.oneReferenceBlock = ^(NSString *str) {
        NSLog(@"%@",str);
    };
    vc.moreReferenceBlock = ^(NSString *str, NSString *str1) {
        NSLog(@"%@  %@",str,str1);

    };
    [self.navigationController pushViewController:vc animated:YES];