CALayer掩码在设备旋转时不会更新

Question

I have a CAShapeLayer subclass that creates a hexagon as a path from it's bounds. I have another CALayer and add an image as the CALayer's content and then I set the CALayer's mask property to the hexagon layer. When I add this as a sublayer of my viewController's view the image displays correctly (clipped as a hexagon).

-(void)viewDidLoad {

    [super viewDidLoad]; 
    MBFHexLayer *hex = [MBFHexLayer hexLayer]; 
    hex.orientation = MBFHexOrientationPointyTopped; 
    hex.frame = self.view.bounds;

    _hexTile = [CALayer layer];
    _hexTile.frame = self.view.bounds;
    _hexTile.mask = hex;
    _hexTile.contents = (id)[UIImage imageNamed:@"grass.jpg"].CGImage;

    [self.view.layer addSublayer:_hexTile]; 
}

In the viewDidLayoutSubviews I set the bounds of the image layer to the bounds of the view and I have overridden layoutSublayers in my hexagon mask layer to recompute the path.

- (void)viewDidLayoutSubviews {

    [super viewDidLayoutSubviews];

    NSLog(@"View Bounds:%@", NSStringFromCGRect(self.view.bounds));
    _hexTile.frame = self.view.bounds;
    [_hexTile setNeedsLayout];
    [_hexTile layoutSublayers];
}

CAShapeLayer:

-(void)layoutSublayers {

    [self recalcGeometry];
    self.path = [self layerPath].CGPath;
}

When I rotate the display the layoutSublayers method is not called on my hexagon mask layer and the image is no longer clipped correctly in the view.

I am confused as to what the correct update chain is and any pointers would be greatly appreciated.

Answer 1

I would implement this Method:

- (void) didRotateFromInterfaceOrientation: (UIInterfaceOrientation)  fromInterfaceOrientation {
 //relayout 
  }

Answer 2

1. You should subclass your view, as it's not MVC approach to implement layers in the controller.
2. You you call layoutSublayers you should also call super .
3. When you subclass your view and implement the layer there, keep a reference to it and in method layoutSublayersOfLayer: you should call setFrame:

You may check similar approach here: https://github.com/natalia-osa/NORosettaView/blob/master/NORosettaView/Classes/Example2View.m