Question

我最近将我的OS X App中的一个视图转换为图层托管，并且所有这些视图都在Mountain Lion下运行良好，但是我的一位测试人员抱怨这些图层没有在Snow Leopard下显示。我编写了一个小测试应用程序来执行进一步的测试（源代码here），这个测试应用程序在10.6下也不起作用。

以下是设置图层的主要代码：

- (id)initWithFrame:(NSRect)frameRect
{
    NSLog(@"initWithFrame");
    self = [super initWithFrame:frameRect];
    if (self != nil)
    {
        srand((unsigned)time(NULL));

        _rootLayer = [[CALayer alloc] init];
        _rootLayer.delegate = self;
        _rootLayer.anchorPoint = CGPointMake(0.0, 0.0);
        _rootLayer.frame = NSRectToCGRect([self bounds]);
        _rootLayer.needsDisplayOnBoundsChange = NO;
        _rootLayer.masksToBounds = YES;

        self.layer = _rootLayer;
        self.wantsLayer = YES;

        _backgroundLayer = [[CALayer alloc] init];
        _backgroundLayer.delegate = self;
        _backgroundLayer.anchorPoint = CGPointMake(0.5, 0.5);
        _backgroundLayer.frame = CGRectInset(NSRectToCGRect([self bounds]), BACKGROUND_INSET, BACKGROUND_INSET);
        _backgroundLayer.cornerRadius = 5.0;
        _backgroundLayer.needsDisplayOnBoundsChange = NO;
        _backgroundLayer.masksToBounds = YES;
        [_rootLayer addSublayer:_backgroundLayer];

        _mouseLayer = [self _createOtherLayer];
        _mouseLayer.opacity = 0.5;
        for (unsigned i = 0; i < NUM_OTHER_LAYERS; i++)
            _otherLayers[i] = [self _createOtherLayer];

        [_backgroundLayer addSublayer:_mouseLayer];

        [_rootLayer setNeedsDisplay];
        [_backgroundLayer setNeedsDisplay];

        [self _positionOtherLayersInRect:frameRect];

        _trackingArea = nil;
        [self updateTrackingAreas];
    }

    return self;
}

以下是创建其他图层的方法：

- (CALayer *)_createOtherLayer
{
    CALayer *layer = [[CALayer alloc] init];
    layer.delegate = self;
    layer.anchorPoint = CGPointMake(0.5, 0.5);
    layer.bounds = CGRectMake(0.0, 0.0, 64.0, 64.0);
    layer.position = CGPointMake(0.0, 0.0);
    layer.needsDisplayOnBoundsChange = NO;
    layer.masksToBounds = YES;
    layer.shadowColor = CGColorGetConstantColor(kCGColorBlack);
    layer.shadowOffset = CGSizeMake(2.0, -2.0);
    layer.shadowRadius = 2.0;
    layer.shadowOpacity = 1.0;
    [_backgroundLayer addSublayer:layer];
    [layer setNeedsDisplay];
    return layer;
}

有人可以建议为什么这些图层在10.6下不起作用吗？

Answer 1

如果更改会发生什么：

CALayer *layer = [[CALayer alloc] init];

为：

CALayer *layer = [CALayer layer];

不确定为什么它会有所作为，但值得一试。您是否尝试过使用insertSubLayer：atIndex：而不是addSubLayer？

核心动画图层不在Snow Leopard下显示

1 个答案: