I have several ViewController chained together with segue in a simple hierarchy.
In each of them :
[self performSegueWithIdentifier:#"myController" sender:myVar];
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if([segue.identifier isEqualToString:#"myController"]){
MyController *controller = (MyController *)segue.destinationViewController;
controller.myVar = sender;
}
}
I'm looking for the simplest way to integrate a top navigation bar with a back button. I know I can use something like this in viewWillAppear :
UINavigationBar *myNav = [[UINavigationBar alloc]initWithFrame:CGRectMake(0, 0, x, y)];
[self.view addSubview:myNav];
But in this case the navigation bar hides a part of the view (like a "position:absolute" would in css).
I can add a Navigation Controller which solves the problem above but from what I understand this will make my segue useless, which I don't want.
This is exactly what UINavigationController is for. Your first view controller (called the root) is embedded in a navigation controller. Additional view controllers are then pushed onto the navigation controller.
UINavigationController automatically manages the navigation bar on the top and creates the back button for you.
Once you have embedded your view controller in a navigation controller, you can use push segues.
Related
I have the following in Interface Builder:
The top left is my main view controller where I have 2 buttons that have segue to two UIViewControllers. These two UIViewControllers are linked with the Tab Bar Controller. However, how could I make those 2 buttons to link to specifically to one/other views? Right now it's connected specifically, but it (or something else) causes the bar tab not show up.
Is it the problem that I don't have the Tab Bar Controller connected to the main view?
Yes, you're right that the problem occurs because the tab bar controller needs to be the destination of the segues. Fix it like this:
In IB, erase the segues from the two buttons and create two new ones, one from each button to the tab bar controller. Give each one an identifier, like buttonA from one button and buttonB from the other.
In the view controller, implement prepareForSegue for each segue understanding that the destination is a tab bar controller and that each segue requires a different tab selection...
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"buttonA"]) {
UITabBarController *tabBarController = (UITabBarController *)segue.destinationViewController;
tabBarController.selectedIndex = 0;
}
if ([segue.identifier isEqualToString:#"buttonB"]) {
UITabBarController *tabBarController = (UITabBarController *)segue.destinationViewController;
tabBarController.selectedIndex = 1;
}
}
That's not quite how the tabBarController works.
I can see your initial view controller is the one on the top left, and it pushes either of the other two on the right on to the navigation stack if you push a button. But in your current setup, at no point does the tab controller itself get pushed on to the stack.
Instead, you would want to have your initial view controller push the tab bar controller on to the stack, through a button or otherwise, and the tab bar controller will display your other two view controllers as its setup to do.
I am having a strange problem that I can't seem to find the cause for.
When attempting to present a modal view controller on a navigation controller the navigation controller is popping all of my view controllers underneath when the modal is dismissed.
So after pushing a few view controllers and presenting a modal on the topViewController, I end up back at the rootViewController when the modal is dismissed.
Anyone had this happen to them lately, I can't seem to find the reasoning for why this is happening?
This answer is for #rshev:
It was actually a user error. Here's what was happening: I had a view controller with a manually added navigationController on top of it (as a subview/child VC). The nav controller then had 3 VCs in its stack. The third (and visible) VC was presenting an image picker controller. When the image picker was dismissed, I momentarily saw my third VC , then it quickly popped back to the 1st, discarding the other two VC's from memory.
So what went wrong? What I didn't realize is that viewDidAppear (and viewWillAppear) was being called on my content view controller (the one with nav controller for its subview). This content VC was actually setting its navigation controller (and adding it as a subview) on viewDidAppear, thus covering up the original nav controller.
To solve it, I just added a static boolean to determine when the first VC FIRST appears, like so:
- (void) viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
static BOOL firstAppearance = YES;
if (firstAppearance)
{
firstAppearance = NO;
UINavigationController *navController = [self.storyboard instantiateViewControllerWithIdentifier:#"NavigationController"];
[navController.view setFrame:self.view.bounds];
[self.view addSubview:navController.view];
[self addChildViewController:navController];
[navController didMoveToParentViewController:self];
}
}
Hope that helps.
I have a tab bar controller with 4 tabs and each tab is their own UINavigationController, which is how you're supposed to nest tab bar and navigation controller's together. The initial tab is a TableViewController and works/appears the way that it should. From the tableVC I can push standard view controller's onto the navigation controller with:
[self.navigationController pushViewController:VC animated:YES];
and it works properly.
If I attempt to push another TableViewController onto the navigation with the same method it works the same way, but the initial tab bar does not get pushed off screen like it should, it just stays in place.
Why would the tab bar stay on screen even though I am pushing a new VC onto the navigation?
I have tested with multiple instances of different TableVC's and it only happens with a table view controller.
Here is the code I'm using:
- (void)pushTableVC
{
TestTableVC *tableVC = [[TestTableVC alloc] init];
[self.navigationController pushViewController:tableVC animated:YES];
}
This will push the new table view onto the stack, but the tab bar from the parent VC stays in place and does not get pushed off screen like it should.
You should call the method setHidesBottomBarWhenPushed: on the view controller you are pushing to correctly hide the tab bar.
UIViewController *viewController = [[UIViewController alloc] init];
[viewController setHidesBottomBarWhenPushed:YES];
[[self navigationController] pushViewController:viewController animated:YES];
When you use a UITabBarController, the tab bar always stays on screen, even as you push additional view controllers onto an embedded UINavigationController. You will see this in any app that has a UITabBarController implemented, unless they implement custom behavior to change this.
The UINavigationController contains everything above the UITabBar, but does not contain the UITabBar itself, so it would not be able to push it offscreen.
I simply want to add a navigation bar (with some nav bar button) on a presented modal controller with storyboard.
Programmatically with XIBs, it looks like that :
SDMapController *mapController = [[SDMapController alloc] initWithNibName:#"SDMapController" bundle:nil];
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:mapController];
[self presentModalViewController:navigationController animated:YES];
But I have no idea how to handle it with Storyboard. I guess i have to implement some code on the -(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender method but since the destinationController property of segue object is readonly, i don't really know how to do this.
Any idea ?
You have to implement the prepare for segue, only if you want to pass on some data to your presented view controller. Otherwise you can leave it empty. The presenting of the View Controller is from the Interface Builder. You add a navigation controller with it's root view controller and make a segue (ctrl + drag) to the navigation controller. Set the segue type to modal, and give it an ID. You can trigger this segue from code by calling [self perforSegueWithIdentiefier:#"MySegueID"];. If you dragged the segue from a button or a table view cell, it will be triggered automatically when you tap on it, without calling this method. As I said, in the prepareForSegue method, the segue.destinationViewController will bee the presented navigation controller. You can access it's topViewController if you need and pass some data to it.
I have an application with several view controllers controlled from a tab bar controller. From one of these view controllers I want to (on clicking a button) segue to another view controller and retain the tab bar at the bottom of the segued to view.
I've used
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if ([segue.identifier isEqualToString:#"newView"]){
UIViewController *controller =segue.destinationViewController;
controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:controller animated:YES];
}
}
This works fine except the tab bar is missing from the segued to view (a placeholder shows for it in the storyboard, but it doesn't show up when the app is run)
I've also tried replacing
[self presentModalViewController:controller animated:YES];
with
[self presentViewController:controller animated:YES completion:nil];
but that doesn't work either.
A bit of debugging shows that for the segued-to view controller, the tabBarController property is set to nil.
Is there anyway to retain the tab bar in the segued-to view controller?
From your explanation, I don't think you want a modal controller. Modal is used to overlay, rendering your tab bar useless. From your storyboard, select your segue and select push, not modal.
Push vs Modal (Note the tab bar):