1.如果是只读,需要用线程锁吗 ?
不需要。线程安全是由于多线程访问和修改共享资源而引起不可预测的结果。因此,如果都是访问共享资源而不去修改共享资源也可以保证线程安全,比如:设置只读属性的全局变量
2.自动释放池原理?
3.SDWebImage如何处理gif图?从缓存取出来还是gif吗?
4.手势冲突如何处理?
a.修改手势响应优先级
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldBeRequiredToFailByGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer;
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRequireFailureOfGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
b.同时响应
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
5.按层遍历二叉树?
6.手写多边形view,不规则图形怎么判断点击事件?
UIBezierPath绘制多边形,- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event; [UIBezierPath containsPoint:]判断点击的点是否在图形内