iOS缩放动画

 UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
    view.backgroundColor = [UIColor redColor];
    [self.view addSubview:view];
    
    CABasicAnimation *animation=[CABasicAnimation animationWithKeyPath:@"transform.scale"];
    animation.fromValue=[NSNumber numberWithFloat:0.5];
    animation.toValue=[NSNumber numberWithFloat:1.0];
    animation.duration=1.0;
    animation.autoreverses=YES;
    animation.repeatCount=0;
    animation.removedOnCompletion=NO;
    animation.fillMode=kCAFillModeForwards;
    [view.layer addAnimation:animation forKey:@"zoom"];