macos - 你能在NSView上设置根层的anchorPoint吗？

Question

是否可以修改图层支持的 NSView 根 CALayer 上的 anchorPoint 属性？

我有一个名为 myView 的 View ，似乎每次我设置 anchorPoint 时，它都会在下一个运行循环中被覆盖。我正在这样做:

NSView *myView = [[myView alloc] initWithFrame:CGRectMake(0, 0, 50, 50)];

//set the root layer
myView.layer = [CALayer layer];
myView.wantsLayer = YES;

//gets overridden on the next run loop
myView.layer.anchorPoint = CGPointMake(1,1);

Answer 1

On 10.8, AppKit will control the following properties on a CALayer (both when "layer-hosted" or "layer-backed"): geometryFlipped, bounds, frame (implied), position, anchorPoint, transform, shadow*, hidden, filters, and compositingFilter. … Use the appropriate NSView cover methods to change these properties.

基本上，它将把 anchor 设置为 [0.5,0.5] 中的 [0,0]，为了解决这个问题，我使用了类似的东西:

+(void) accountForLowerLeftAnchor:(CALayer*)layer
{
    CGRect frame = layer.frame;
    CGPoint center = CGPointMake(CGRectGetMidX(frame), CGRectGetMidY(frame));
    layer.position = center;
    layer.anchorPoint = CGPointMake(0.5, 0.5);
}