graph - How to detect the touch on a line drawn in drawrect?

Question

I'm preparing a graph plot application,and i need to detect the touch of the user on the drawn lines using drawRect() method and show an alert message to user with the values at that point. I have drawn the lines using NSBezierPath. Is there any way to detect the touch only on the lines ,not at any other places of screen?

Answer 1

我认为唯一要做的就是检测绘制线的初始点和最终点并添加约束，以便 touch 不会提供除 line 之外的任何值。这可以使用矩形概念来完成，绘制的线将是矩形的对角线，我们可以根据矩形和它的对角线放置约束。