在视图中重新定位CGPath / UIBezierPath [英] Reposition CGPath/UIBezierPath in View

问题描述

是否可以在视图上重新定位已绘制的CGPath / UIBezierPath？我想移动或更改路径的位置然后可能回想起drawinRect方法再次显示图形。

Is it possible to reposition an already drawn CGPath/UIBezierPath on a view? I would like to move or change a path's position then perhaps recall the drawinRect method to just show the drawing again.

推荐答案

从你的问题听起来你正在使用核心图形在 drawRect：中绘制路径（与使用 CAShapeLayer 相比）我将首先解释该版本。

From your question it sounds like you are drawing the path using Core Graphics inside drawRect: (as compared to using a CAShapeLayer) so I'll explain the version first.

您可以通过转换另一个来创建新路径路径。平移变换将变换后的对象在x和y中移动一定距离。因此，使用平移变换，您可以在x和y中移动现有路径一定数量的点。

You can create a new path by transforming another path. A translation transform moves the transformed object a certain distance in x and y. So using a translation transform you can move your existing path a certain number of points in both x and y.

CGAffineTransform translation = CGAffineTransformMakeTranslation(xPixelsToMove,
                                                                 yPixelsToMove);
CGPathRef movedPath = CGPathCreateCopyByTransformingPath(originalCGPath,
                                                         &translation);

然后你可以使用 movedPath 来绘制就像你现在一样。

Then you could use the movedPath to draw the same way you are already doing.

你也可以改变修改相同的路径

You could also change modify the same path

yourPath = CGPathCreateCopyByTransformingPath(yourPath,
                                              &translation);

并简单地重新绘制。

如果使用形状图层，移动它会更容易。然后，您只需使用位置属性更改图层的位置。

If you are using a shape layer, moving it is even easier. Then you only have to change the position of the layer using the position property.

如果你想使用形状图层，你可以简单地创建一个新的CAShapeLayer并将其路径设置为你的CGPath。你需要QuartzCore.framework，因为CAShapeLayer是Core Animation的一部分。

If you want to use a shape layer you can simply create a new CAShapeLayer and set its path to be your CGPath. You will need QuartzCore.framework for this since CAShapeLayer is part of Core Animation.

CAShapeLayer *shape = [CAShapeLayer layer];
shape.path = yourCGParth;
shape.fillColor = [UIColor redColor].CGColor;

[someView.layer addSublayer:shape];

然后移动形状你只需改变它的位置。

Then to move the shape you simply change its position.

shape.position = thePointYouWantToMoveTheShapeTo;

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