-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{        /*     1,不使用动画     UIViewAnimationTransitionNone          2,从左向右旋转翻页     UIViewAnimationTransitionFlipFromLeft          3,从右向左旋转翻页，与UIViewAnimationTransitionFlipFromLeft相反     UIViewAnimationTransitionFlipFromRight          4,卷曲翻页，从下往上     UIViewAnimationTransitionCurlUp          5,卷曲翻页，从上往下     UIViewAnimationTransitionCurlDown     */    FirstViewController *firstVC=[[FirstViewController alloc]init];        [UIView  beginAnimations:nil context:NULL];    //置动画块中的动画属性变化的曲线    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];    //设置持续时间    [UIView setAnimationDuration:0.5];    //设置过渡的动画效果    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.navigationController.view cache:NO];        [self.navigationController pushViewController:firstVC animated:YES];    //提交动画    [UIView commitAnimations];    }