IOS 简单的block反向传值示例1.声明block属性@property(nonatomic,copy)void(^

#import "ViewController.h"
@interface ViewController ()
@property (nonatomic, copy) void (^loglock)(NSString*);
@end

@implementation ViewController
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

    self.loglock(@"123");
   
}
- (void)viewDidLoad {
    [super viewDidLoad];
    
self.loglock = ^(NSString *str) {
    NSLog(@"%@",str);
};
    
}

1.声明block属性 @property (nonatomic, copy) void (^loglock)(NSString*);

2.block赋值 self.loglock(@"123");

3.block回调接收传值 self.loglock = ^(NSString *str) { NSLog(@"%@",str); };