继承UITabBarController 在ctrl里面执行如下语句
-(void)removeSystemBar
{
UIView *transitionView = [self.view.subviews objectAtIndex:0];
transitionView.frame = CGRectZero;
UIView *systemBarView = [self.view.subviews objectAtIndex:1];
systemBarView.hidden = YES;
}
原文：http://www.cnblogs.com/417460188dy/p/4818566.html