ios 7 下自定义alertView

   项目需要适配ios7，在启动页面原来ios6可以运行的alertView上加addsubView已经不起作用，所以决定自己写一个alertView。思路也就是自己做模态蒙板半透明的，给view做show，和close的动画。下面上代码，动画部分是直接取自己code4上面的。

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#import <QuartzCore/QuartzCore.h>

- (void)show{
    self.STAlertView.center = self.view.center;
    [self.view addSubview:self.STAlertView];
    CAKeyframeAnimation *popAnimation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
    popAnimation.duration = 0.4;
    popAnimation.values = @[[NSValue valueWithCATransform3D:CATransform3DMakeScale(0.01f, 0.01f, 1.0f)],
                            [NSValue valueWithCATransform3D:CATransform3DMakeScale(1.1f, 1.1f, 1.0f)],
                            [NSValue valueWithCATransform3D:CATransform3DMakeScale(0.9f, 0.9f, 1.0f)],
                            [NSValue valueWithCATransform3D:CATransform3DIdentity]];
    popAnimation.keyTimes = @[@0.2f, @0.5f, @0.75f, @1.0f];
    popAnimation.timingFunctions = @[[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                     [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                     [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
    [self.STAlertView.layer addAnimation:popAnimation forKey:nil];
}

背景加上的是黑色半透明的view，注意不要直接调view的alpha

UIView *maskView=[[UIView alloc] initWithFrame:self.view.bounds];
    maskView.backgroundColor=[UIColor colorWithRed:40/255.0 green:43/255.0 blue:52/255.0 alpha:0.6];
    [self.view addSubview:maskView];
    [maskView release];

隐藏动画部分，动画下去之后移除alertView

- (IBAction)hideAlertAction:(id)sender {
    CAKeyframeAnimation *hideAnimation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
    hideAnimation.duration = 0.4;
    hideAnimation.values = @[[NSValue valueWithCATransform3D:CATransform3DMakeScale(1.1f, 1.1f, 1.0f)],
                             [NSValue valueWithCATransform3D:CATransform3DMakeScale(1.0f, 1.0f, 1.0f)],
                             [NSValue valueWithCATransform3D:CATransform3DMakeScale(0.00f, 0.00f, 0.00f)]];
    hideAnimation.keyTimes = @[@0.2f, @0.5f, @0.75f];
    hideAnimation.timingFunctions = @[[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
    hideAnimation.delegate = self;
    [self.STAlertView.layer addAnimation:hideAnimation forKey:nil];
    
}
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
    [self.STAlertView removeFromSuperview];
}

在这自定义这个alertView的部分没有做高强度测试，可以自己慢慢优化