动画：view从点逐渐变大（放大效果）

-(void) animationAlert:(UIView *)view
{
    CAKeyframeAnimation *popAnimation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
    popAnimation.duration = ;
    popAnimation.values = @[[NSValue valueWithCATransform3D:CATransform3DMakeScale(0.01f, 0.01f, 1.0f)],
                            [NSValue valueWithCATransform3D:CATransform3DMakeScale(1.0f, 1.0f, 1.0f)],
                            [NSValue valueWithCATransform3D:CATransform3DIdentity]];
    popAnimation.keyTimes = @[@0.0f, @0.5f, @0.75f, @1.0f];
    popAnimation.timingFunctions = @[[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
    view.frame=CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y, kScreenWidth, kScreenHeight);
    [view.layer addAnimation:popAnimation forKey:nil];

    //弹出放大-缩小效果

}

//调用
  _vi_max=[[UIView alloc]init];
  [self animationAlert:_vi_max];