在下面的代码中-(IBAction)showAbout:(id)sender{AboutView*a=[[AboutViewalloc]initWithNibName:@"AboutView"bundle:nil];[selfsetAboutView:a];[UIViewsetAnimationDuration:.75];[[selfaboutView]setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];[selfpresentModalViewController:[selfaboutView]animated:Y