我有一个CALayer，我想显示它然后隐藏它。CALayer*layerOne=[CALayerlayer];[layerOneaddSublayer:textOne];layerOne.frame=CGRectMake(0,0,size.width,size.height);[layerOnesetMasksToBounds:YES];layerOne.opacity=0.0;CABasicAnimation*animationOne=[CABasicAnimationanimationWithKeyPath:@"opacity"];[animationOnesetDuration: