barButtonItem in UIToolBar of NavigationController not working in ios7 - ios7

Question

I am trying to add BarButton in UIToolBar of NavigationController. I found on below code on stack over flow. But it is not working in ios7. If anything changed why it shows nothing on tool bar.
[self.navigationController setToolbarHidden:NO];
UIBarButtonItem *buttonItem = [[ UIBarButtonItem alloc ] initWithTitle: #"Select All"
style: UIBarButtonItemStyleBordered
target: self
action: #selector(selectAll:) ];
UIBarButtonItem *buttonNext = [[UIBarButtonItem alloc]initWithTitle:#"Next" style:UIBarButtonItemStyleBordered target:self action:#selector(goNext:)];
self.toolbarItems = [ NSArray arrayWithObjects: buttonItem, buttonNext, nil ];

Answer 1

//allocate the tool bar
UIToolbar *toolBar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 416, 320, 44)];
// create bar btns
UIBarButtonItem *back = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemRewind target:self action:#selector(Back)];
//set spacing
UIBarButtonItem *flexibleSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
UIBarButtonItem *forward = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFastForward target:self action:#selector(Forward)];
// add btns to the bar
[toolBar setItems:[NSMutableArray arrayWithObjects:back,flexibleSpace,forward, nil]];
// adds the toobar to the view
[self.view addSubview:toolBar];

Answer 2

I found the problem. Above code is correct. The reason why there is no button showing in the tool bar . i also have this function in my class. this is a empty function. so it overwrite the default self.toolbarItems = [ NSArray arrayWithObjects: buttonItem, buttonNext, nil ];
After Removing the below code. Its working Perfect Now.
- (void)setToolbarItems:(NSArray *)toolbarItems animated:(BOOL)animated
{
}