How to switch from one tab to another and back? - ios

Question

I've got a little problem on navigating through my views.
Here is my configuration :
Ive got 1 Tabbar Controller with 2 relationship segues to 2 simple views embedded inside a navigation controller.
Now i want to navigate from view controller 1 to view controller 3 and i also want to show the correct tab selected inside the tabbar. And if i come from view controller 1, i also want that the back button redirects me the the previous tab. I tried something with a segue connected between that views, but if i do so, it just pushes the view controller onto the navigation stack but not changes the tab. So my question now is, what is the best way of managing this Problem
Screenshot:

Answer 1

Here's a way to do it. But I'm posting this really to illustrate why you shouldn't do it.
I'm using VC2's and VC3's view tag property to pass navigation data around, which has the effect of tightly coupling all three objects.
I override back bar button for the VC1->VC3 context. You lose consistency.
VC3->VC2 provides back animation. VC3->VC1 has no animation as it flips from one tab to another. More inconsistency
VC1->VC3, tap Tab Item 2 transitions to VC2. UI confusion.
Anyway if you still want to do this...
.
ViewController1
Has a "jump to VC3" button, wire up to jumpToVC3:
//ViewController1.m
#import "ViewController1.h"
#implementation ViewController1
- (IBAction)jumpToVC3:(id)sender {
NSArray* viewArray = [[[self.tabBarController viewControllers] objectAtIndex:1] viewControllers];
[[[viewArray lastObject] view] setTag:1];
[self.tabBarController setSelectedIndex:1];
}
#end
"jumptToVC3" switches us to tab 2 and sets the frontmost view's view tag property to 1. IF the frontmost view is VC2, this triggers an immediate segue to VC3. If the frontmost view is VC3, this sets up the back button correctly. If other View Controllers get added to this stack, this navigation will break.
ViewController2
Has a "move to VC3" button, wired to a storyboard segue to VC3 "toVC3"
// ViewController2.m
#import "ViewController2.h"
#import "ViewController3.h"
#implementation ViewController2
//we use the view.tag property as a switch:
//0 = do nothing
//1 = segue to VC3
//2 = go to tab 0
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
if (self.view.tag ==1){
[self performSegueWithIdentifier:#"toVC3" sender:self];
} else if (self.view.tag == 2){
[self.tabBarController setSelectedIndex:0];
}
self.view.tag = 0;
}
- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if (self.view.tag ==1) {
[[segue.destinationViewController view] setTag:1];
} else {
[[segue.destinationViewController view] setTag:0];
}
self.view.tag = 0;
}
- (void) viewWillDisappear:(BOOL)animated
{
self.view.tag = 0;
}
#end
ViewController3
Overrides the back button if it's view.tag is set to 1. If you want both context's back buttons to be consistent, you will need to override for the default behaviour as well. You will not be able to get a standard back button look for this override behaviour.
// ViewController3.m
#import "ViewController3.h"
#implementation ViewController3
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
if (self.view.tag == 1) {
self.navigationItem.leftBarButtonItem =
[[UIBarButtonItem alloc] initWithTitle:#"0.0"
style:UIBarButtonItemStyleBordered
target:self
action:#selector(goBack:)];
}
self.view.tag = 0;
}
- (IBAction)goBack:(id)sender {
[[[[self.navigationController viewControllers]
objectAtIndex:0] view] setTag:2];
[self.navigationController popToRootViewControllerAnimated:YES];
}
#end