Question

for (NSValue * point in points){
    CGPoint p = point.CGPointValue;
    CAShapeLayer *point = [CAShapeLayer layer];
    [point setPath:[[UIBezierPath bezierPathWithOvalInRect:CGRectMake(p.x, p.y, 100, 100)] CGPath]];
    [point setStrokeColor:nil];
    [point setFillColor: [[UIColor blueColor] CGColor]];
    [point setZPosition:2];
    [self.layer addSublayer:point];
}

所以我有这个代码，这个点是一个NSMutableArray，它包含了CGPoints的NSValue，但是我总是遇到这个错误。

*** Terminating app due to uncaught exception 'NSGenericException', reason: '*** Collection <__NSArrayM: 0x7faf214a1a50> was mutated while being enumerated.'

我做错了什么？无论如何我可以解决这个问题吗？

Answer 1

当您在两个不同的线程中处理可变数组同步时，会发生错误这是一个同步问题复制点数组可能会解决您的问题只需修改您的代码如下：

for (NSValue * point in points.copy){
    CGPoint p = point.CGPointValue;
    CAShapeLayer *shapeLayer = [CAShapeLayer layer];
    [shapeLayer setPath:[[UIBezierPath bezierPathWithOvalInRect:CGRectMake(p.x, p.y, 100, 100)] CGPath]];
    [shapeLayer setStrokeColor:nil];
    [shapeLayer setFillColor: [[UIColor blueColor] CGColor]];
    [shapeLayer setZPosition:2];
    [self.layer addSublayer:shapeLayer];
}

如何从一个循环制作一套圆形CAShapeLayer

1 个答案: