小编Pab*_*o3D的帖子

我正在尝试向我的CAShapeLayer路径添加子路径，但除非我首先分配nil到路径然后重新分配myPath到CAShapeLayer. 我已经尝试过setNeedsRedisplay但它不起作用。

LoadView这是wheremyPath和are 属性中的代码shapeLayer：

// The CGMutablePathRef
CGPathMoveToPoint(myPath, nil, self.view.center.x, self.view.center.y);
CGPathAddLineToPoint(myPath, nil, self.view.center.x + 100.0, self.view.center.y - 100.0);

// The CAShapeLayer
shapeLayer = [CAShapeLayer layer];
shapeLayer.path = myPath;
shapeLayer.strokeColor = [UIColor greenColor].CGColor;
shapeLayer.lineWidth = 2.0;
[self.view.layer addSublayer:shapeLayer];

例如，这是我对路径进行更改的地方。我只是添加一个新的子路径myPath：

- (void)handleOneFingerSingleTapGesture:(UIGestureRecognizer *)sender
{
    // I add a new subpath to 'myPath'
    CGPathMoveToPoint(myPath, nil, self.view.center.x, self.view.center.y);
    CGPathAddLineToPoint(myPath, nil, self.view.center.x + 100.0, self.view.center.y + 100.0); …