block使用时不判空，当用block不被实现，会crash.

- (instancetype)initWithFrame:(CGRect)frame {self = [super initWithFrame:frame];self.backgroundColor = [UIColor whiteColor];if (self) {for (int i = 0; i<3; i++) {ImageTitleButton *btn = [[ImageTitleButton alloc]initWithType:ImageTopTitleBottom andTitleFont:NFont(13) andTitle:@[@"好友",@"关注",@"粉丝"][i] andImage:[UIImage imageNamed:@[@"friends",@"follow",@"fans"][i]] andFrame:CGRectMake(0, 0, PPImageTitleBtnW, PPImageTitleBtnH)];//                if(self.clickAction){self.clickAction(button.titleButton.titleLabel.text,button);} }];if (i == 0) {}}        [self upFrame];}return self;
}