iOS 隐藏tabbar

-(void)viewwillappear:(bool)animated
{
    
    nsarray *array=self.tabbarcontroller.view.subviews;
    
    uiview *view=array[2];
    
    view.frame=cgrectmake(0, [uiscreen mainscreen ].bounds.size.height, [uiscreen mainscreen ].bounds.size.width, 49);
    
    [uiview commitanimations];
    
}

- (void)viewwilldisappear:(bool)animated
{
    
    nsarray *array=self.tabbarcontroller.view.subviews;
    
    uiview *view=array[2];
    
    view.frame=cgrectmake(0, [uiscreen mainscreen ].bounds.size.height-49, [uiscreen mainscreen ].bounds.size.width, 49);
    
    [uiview commitanimations];
}