ios - 如何在layer上实现橡皮擦一样的功能呢

Question

比如，我在shapelayer上绘制了一条颜色是红色的UIbezierPath。如何想橡皮擦一样可以擦掉这条线

Answer 1

1. If you have an image as background, then you can draw the image as a pattern on bezierpath and it will virtually give you an eraser effect. It works :)
   brushPattern=[[UIColor alloc]initWithPatternImage:[UIImage imageNamed:@"image.jpg"]];

// Here image.jpg is your background image

1. The eraser effectively draws a line that is one color, each on top of the background of an already drawn path. What you might want to note is that it is an eraser line so that if the background color changes otherwise you lose the erase you can update the eraser line's stroke color.

2. Based on your answer to Jeremy, it seems like you are trying to do the dotted line. you setLineDash:number:phase:
   UIBezierPath *path = [UIBezierPath new];

CGFloat dashArray[3];
dashArray[0] = 8;
dashArray[1] = 3;
dashArray[2] = 8;
[path setLineDash:dashArray count:dashCount phase: 0.0];