ios点击键盘以外空白区域隐藏键盘

在view上添加一个UITapGestureRecognizer

- (void)viewDidLoad

{

    [super viewDidLoad];

    UITapGestureRecognizer *tapGr = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(viewTapped:)];

    tapGr.cancelsTouchesInView = NO;

    [self.view addGestureRecognizer:tapGr];

}

-(void)viewTapped:(UITapGestureRecognizer*)tapGr{

    [activitySearchBar resignFirstResponder];

}