Is it possible to check when the back button is pressed in a UINavigationController stack? I've tried adding a action and target to self.navigationItem.backBarButtonItem to no avail.
Anyone have any solutions?
You can try my way:
Write in your ViewController:
UIBarButtonItem *backBt = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:#"imageNameOfBackButton"] style:UIBarButtonItemStyleBordered target:self action:#selector(backBt_touch:)];
self.navigationItem.leftBarButtonItem = backBt;
And action method:
- (void)backBt_touch:(id)sender {
[self.navigationController popViewControllerAnimated:YES];
}
You have to take a photo of back button you want.
Animation of hiding back button when viewController is popped is not the same animation of iOS!
P/s:
I've get it from simulator. Hope it useful! :)
One way to get at this would be to override viewWillDisappear in the UIViewController that is visible when the back button is pressed:
- (void)viewWillDisappear:(BOOL)animated {
if (self.isMovingFromParentViewController) {
// handle back button press
}
}
Obviously this doesn't directly intercept the press on the back button itself, but it gives you a chance to perform logic at that time.
Related
How to set an IBAction for the edit button in the NavigationBar created using the following code
self.navigationItem.leftBarButtonItem = [self editButtonItem];
Since you are assigning the left bar button programmatically, you must create the button yourself. When you instantiating the button, you can also set the callback action something like this:
UIBarButtonItem *editButton = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemEdit
target:self
action:#selector(editButtonPressed:)];
self.navigationItem.leftBarButtonItem = editButton;
When the edit button is pressed, the following method will be called
- (void)editButtonPressed:(id)sender
{
// do something
}
Since you are already working in code, rather than Interface Builder, it's probably easier to assign a selector programmatically as well:
[self.navigationItem.leftBarButtonItem setAction:#selector(doSomething:)];
I have following code which add BackButton on my view's navigation item's tabbar. It works fine.
// Add back button
UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:#"Back" style:UIBarButtonItemStylePlain target:nil action:nil];
[view.navigationController setNavigationBarHidden:NO animated:YES];
view.navigationItem.backBarButtonItem = backButton;
view.navigationController.navigationBar.barStyle = UIBarStyleBlack;
[backButton release];
I use following line to navigate to my new view controller but it gets presented with default animation.
[view.navigationController pushViewController:viewController2 animated:YES];
I want to change the way it gets presented so I tried to do it following way.
[viewController2 setModalTransitionStyle:UIModalTransitionStyleFlipHorizontal];
[view.navigationController presentModalViewController:viewController2 animated:YES];
This works fine but I lost my BackButton..!! Is there anyway to present my new view controller with specific transition style and also keep my back button as is?
Thanks.
I found the answer to your question. Put a navigation bar on your viewController2 and add a bar button to it using either interface builder or using code. Then in the action of button press
In your viewController2.m write this function and link it up with the button press if you have added the bar button through interface builder.
-(void) backButtonPressed : (id) sender
{
[self dismissModalViewControllerAnimated:YES];
}
This should solve your problem.
Doing a pushViewController will carry forward the navigationBar and all for you but in your case presenting a viewController as modalViewController will not give you the navigationBar by default so you have to add it manually in your modalViewController which is viewController2 in your case.
Please let me know if you are still facing problems. We can fix it soon and save you some time and frustration.
Cheers!!!
I know that it could seem strange but i need to add a back button on the navigation Bar of the first navigationController's view. I tried like this:
UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:#"Foo" style:UIBarButtonItemStyleBordered target:self action:#selector(foo:)];
self.navigationItem.backBarButtonItem=backButton;
if instead of backBarButtonItem i write leftBarButtonItem the button is showed. My problem is that i need an arrow button as the normal back button. Is this possible?
Usually this works out of the box, but sometimes with modal views / action sheets you may need this. Just before you instantiate your viewcontroller and push it onto navigationcontroller stack, try
UIBarButtonItem *newBackButton = [[UIBarButtonItem alloc] initWithTitle: #"Back" style: UIBarButtonItemStyleBordered target: nil action: nil];
[[self navigationItem] setBackBarButtonItem: newBackButton];
[newBackButton release];
DetailViewController *detailVC = [[DetailViewController alloc]init];
[self.navigationController pushViewController:detailVC animated:YES];
[detailVC release];
I don't think you can do that on the first NavigationController view, because you need to set the backBarButtonItem property in the parent controller, before the child controller is pushed. Also, according the to the Apple docs, the target & action of the backBarButtonItem must be nil.
This question about creating a left-arrow button on a UIToolbar may give you some ideas of how you could work around this using a custom image (for the leftBarButtonItem).
or you could also do the following - I prefer this method. I got this from a different post.
Use following psd that I derived from http://www.teehanlax.com/blog/?p=447
http://www.chrisandtennille.com/pictures/backbutton.psd
Then I just create a custom UIView that I use in the customView property of the toolbar item.
Works well for me.
Hope that helps a little
Of course you can do this. You just need to change the leftBarButtonItem's title to back
then you will get a nice left arrow button with the title back. Then you just change the selector to actually perform a method when the button is clicked. So #selector(foo:)
Here some code on how to achieve the above:
self.navigationItem.leftBarButtonItem.style = UIBarButtonItemStyleDone;
self.navigationItem.leftBarButtonItem.title = #"Back";
self.navigationItem.leftBarButtonItem.target = self;
self.navigationItem.leftBarButtonItem.action = #selector(endTextEnteringButtonAction:);
Let me know if that helps.
Apple Document says:
When this navigation item is immediately below the top item in the stack, the navigation controller derives the back button for the navigation bar from this navigation item.
So If your navigation item is the top of the Stack (as we are talking here) you can't add the back button to the navigation controller, simply because no place he can navigate back to it because it's the top item in the stack.
Updated Answer :
After I searched I found work a round to make a back button in your root view controller in Navigation controller in these link
It's very simple :)
[self.navigationItem setHidesBackButton:YES animated:YES];
UIBarButtonItem* backButton = [[UIBarButtonItem alloc] initWithTitle:#"Start" style:UIBarButtonItemStyleBordered target:self action:#selector(initializeStuff)];
self.navigationItem.leftBarButtonItem = backButton;
For some reason, if I try to go back to the main menu using the back button on the upper left corner, only the title returns to the previous menu, but not the view controller. View controller would return to the previous menu only if I explicitly call popViewControllerAnimated using some other button.
Is there anyway to solve this? I think I've coded something wrong. Tried googling but couldn't find any cases like mine.
I'm getting the exact same problem. Here is my code:
- (IBAction) showGameView:(id) sender {
gameView = [[TCGameViewController alloc] initWithNibName:#"TCGameViewController" bundle:[NSBundle mainBundle]];
[self.navigationController pushViewController:gameView animated:YES];
[gameView release];
}
And when I am done with gameView, I do this:
[self.navigationController setNavigationBarHidden:NO animated:YES];
But all it does when I push the 'back' button is cycle through the navigation bar, but never pops the view. I don't even know how to debug it.
In my other view, "infoView" I call the same code as before except the NavBar is never hidden, but it works just fine.
helps!
This problem can occur when you override the following method in your custom view controller:
- (UINavigationItem*)navigationItem
But you don't specify a UIBarButtonItem for the leftBarButtonItem property of the returned UINavigationItem.
If you use a custom navigationItem, and want the standard back button functionality, you could add a method as follows (remember that every UIViewController has a reference to the navigationController that containts it):
- (void)backButtonTapped
{
[self.navigationController popViewControllerAnimated:YES];
}
And then setup part of the custom navigationItem as follows:
- (UINavigationItem*)navigationItem
{
UIBarButtonItem* newLeftBarButton = [[UIBarButtonItem alloc] initWithTitle:#"Back"
style:UIBarButtonItemStyleBordered
target:self
action:#selector(backButtonTapped)];
UINavigationItem* navigationItem = [[[UINavigationItem alloc] init] autorelease];
Hope this helps.
I'm working on a traditional iPhone UINavigationController app, with automatic back buttons etc.
I am working on when an 'edit' button is pressed. The LHS back icon dims, my new one comes in, and then once I tap the 'edit' button again, the back button comes back.
So far, the back button goes away, and my new one comes in, but I can't put it back! I know what the code should be, but I don't know where to call it.
Here is what I have so far:
(void)setEditing:(BOOL)editing animated:(BOOL)animated {
[self.navigationItem setHidesBackButton:editing animated:animated]; //fades back button
//de 006 - Load in Move section button here.
UIBarButtonItem *saveButton = [[[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemOrganize
target:self action:#selector(altersection:)] autorelease];
self.navigationItem.leftBarButtonItem = saveButton;
Basically I want the inverse of (void)setEditing:(BOOL)editing animated:(BOOL)animated {, where I can do:
self.navigationItem.leftBarButtonItem = nil; //custom button hide
self.navigationItem.hidesBackButton = NO; //replace back button
Is there an inverse of (void)setEditing:(BOOL)editing ?
Not sure I completely understood the question :/
When you press the "Done" button, I believe setEditing get's called again, but with NO as the editing parameter.
So in setEditing you could check for:
if(editing) { .... }
To see if we are entering or leaving the editing state.
You just have to pu if condition in setEditing. Same method gets called on any action on edit button.
You can have code like
if(self.navigationItem.leftBarButtonItem)
{
self.navigationItem.leftBarButtonItem = nil;
self.navigationItem.hidesBackButton = NO;
}
You can also check for both conditions in if.