我想知道有人如何在不使用之前在这里询问的静态图像的情况下在 UILabel 的文本上实现“滑动解锁效果”。
// I'd like to use the uilable's current text to this sample code but not seem to be able to do it.
// ---> UIImage *textImage = [UIImage imageNamed:@"SlideToUnlock.png"];
CGFloat textWidth = textImage.size.width;
CGFloat textHeight = textImage.size.height;
CALayer *textLayer = [CALayer layer];
textLayer.contents = (id)[textImage CGImage];
textLayer.frame = CGRectMake(10.0f, 215.0f, textWidth, textHeight);
CALayer *maskLayer = [CALayer layer];
// Mask image ends with 0.15 opacity on both sides. Set the background color of the layer
// to the same value so the layer can extend the mask image.
maskLayer.backgroundColor = [[UIColor colorWithRed:0.0f green:0.0f blue:0.0f alpha:0.15f] CGColor];
maskLayer.contents = (id)[[UIImage imageNamed:@"Mask.png"] CGImage];
// Center the mask image on twice the width of the text layer, so it starts to the left
// of the text layer and moves to its right when we translate it by width.
maskLayer.contentsGravity = kCAGravityCenter;
maskLayer.frame = CGRectMake(-textWidth, 0.0f, textWidth * 2, textHeight);
// Animate the mask layer's horizontal position
CABasicAnimation *maskAnim = [CABasicAnimation animationWithKeyPath:@"position.x"];
maskAnim.byValue = [NSNumber numberWithFloat:textWidth];
maskAnim.repeatCount = 1e100f;
maskAnim.duration = 1.0f;
[maskLayer addAnimation:maskAnim forKey:@"slideAnim"];
textLayer.mask = maskLayer;
[self.view.layer addSublayer:textLayer];
谢谢