我尝试在UIScrollView上添加CAGradientLayer,以将边缘淡化为透明度。
渐变是正确的,但是当UIScrollView滚动时,我添加的蒙版会移动。
我试图提交CATransaction但它仍然没有成功。
- (void)layoutSubviews
{
[super layoutSubviews];
[CATransaction begin];
[CATransaction setValue:(id)kCFBooleanTrue forKey:kCATransactionDisableActions];
NSObject * transparent = (NSObject *) [[UIColor colorWithWhite:0 alpha:0] CGColor];
NSObject * opaque = (NSObject *) [[UIColor colorWithWhite:0 alpha:1] CGColor];
CAGradientLayer* hMaskLayer = [CAGradientLayer layer];
hMaskLayer.opacity = .7;
hMaskLayer.colors = [NSArray arrayWithObjects:transparent, opaque, opaque, transparent, nil];
hMaskLayer.locations = [NSArray arrayWithObjects:[NSNumber numberWithFloat:0.0],
[NSNumber numberWithFloat:0.2],
[NSNumber numberWithFloat:0.8],
[NSNumber numberWithFloat:1.0], nil];
hMaskLayer.startPoint = CGPointMake(0, 0.5);
hMaskLayer.endPoint = CGPointMake(1.0, 0.5);
hMaskLayer.bounds = self.bounds;
hMaskLayer.anchorPoint = CGPointZero;
self.layer.mask = hMaskLayer;
[CATransaction commit];
}
答案 0 :(得分:2)
掩码我在UIScrollView滚动时添加移动
毫不奇怪,因为图层的位置是基于其超级图层的边界,而界限正是滚动时的变化。
简单的解决方案:将滚动视图放在具有完全相同大小的超级视图中,并将超级视图的层屏蔽。