iOS block传值

@property (nonatomic, copy) void (^SellHouseControllerBlock)(NSString *str);

if (self.SellHouseControllerBlock) {
        self.SellHouseControllerBlock(@"hehe");
}

SellHouseController *newViewController = [[SellHouseController alloc]init];
newViewController.SellHouseControllerBlock = ^(NSString *str){
    NSLog(@"%@",str);
};