我正在尝试用CGContextSetLineDash
.
这是我的代码:
float dashPhase = 0.0;
float dashLengths[] = {30, 30};
CGContextSetLineDash(context, dashPhase, dashLengths, 20.0);
self.previousPoint2 = self.previousPoint1;
self.previousPoint1 = previous;
self.currentPoint = current;
self.mid1 = [self pointBetween:self.previousPoint1 andPoint:self.previousPoint2];
self.mid2 = [self pointBetween:self.currentPoint andPoint:self.previousPoint1];
UIBezierPath* newPath = [UIBezierPath bezierPath];
[newPath moveToPoint:self.mid1];
[newPath addLineToPoint:self.mid2];
[newPath setLineWidth:self.brushSize];
但是,如果我画得很慢,它们就不会出现虚线(见下图顶部),但如果我画得很快,它们会出现(见下图底部)。
为什么会这样?