I have two view controllers on the same storyboard. What I want to do is send an array of string values to the table view control on another view controller.
ViewController2 *second=[self.storyboard instantiateViewControllerWithIdentifier:#"View2"];
second.arrayFromVC1=areaArray;
[self presentViewController:second animated:YES completion:nil];
The second view controller has a toolbar control at the top by default. (See below.)
Passing data to another view controller wasn't easy for me, who has been using Xcode for two weeks. I somehow managed it. So an array of strings is sent to the 2nd view controller through an array variable (arrayFromVC1) set on the 2nd implementation file. I suppose experienced Xcode users know what I'm talking about. Anyway, the 2nd view controller does receive a list of values as shown below.
Well, the problems are that the toolbar control on the 2nd view controller will disappear when the user gets to see the list and that the table view control (UITableView) occupies the entire window. I understand that you can control the size of the table view control by specifying values under the viewDidAppear method. But my question is... Is that how things work with iOS and Xcode? So if I want to display that toolbar control at the top, I have to do it programmatically by writing code under the viewDidAppear method as well?
Thank you for your advice.
Tom
Tom, are you using interface builder and storyboards? If so, select the ViewController in IB, go to Editor (in the top menu) --> Embed In --> Navigation Controller.
This will embed the chosen VC and any VC it segues to (and so on) into a Nav Controller.
Related
Playing around with some Objective-C (well, iOS) and have done the following... loaded some UIButtons programmatically into a UIScrollView. That works well. Though I've always just connected UIViewControllers together using control-click and drag. Now I've created buttons programmatically, I have no idea how to go from one view controller to another in a Storyboard because there is nothing to drag from!
I'm not really sure what code to post as such, because I haven't done anything that /nearly/ works or doesn't work as such. I get how to do it with XIBs. But I suppose the question is : 3 UIButtons have been created programmatically and I have 3 UIViewControllers. How do I access those ViewControllers using my UIButtons?
Thanks
In the Interface builder view control click and drag from the viewcontroller icon under the first view controller, to the middle of the second view controller. A segue will be created, selected the appropriate type.
Now select the segue and in the inspector give it a unique identifier (say 'myNewSegue').
Now in your first viewcontroller you can create a method that has the following code:
-(void)myButtonAction:(id)sender {
[self performSegueWithIdentifier:#"myNewSegue" sender:self];
}
And add this method as a target action to your button:
[myButton addTarget:self
action:#selector(myButtonAction:)
forControlEvents:UIControlEventTouchUpInside];]
A segue doesn't have to have a button at the leading end of it; you can instead draw it from an entire view controller to another. You can also give a segue an identifier, a string that's used as a name for that segue. Once you've done that, you can programmatically trigger that segue by calling -performSegueWithIdentifier:sender:.
To actually call -performSegueWithIdentifier:sender:, though, you'll need to connect the button to a target and action. If you've never done that, read the Event Handling Guide for iOS in your documentation.
I've set up a really simple project using storyboards including two views as shown here: http://i.stack.imgur.com/iRx21.png. The navigation can be done by either selecting a cell in the custom table view or hitting the back button labelled with "<<". Everything works fine except the following:
when I switch between the views, every time an instantiation happens. The profiling shows an increasing number of view objects. I would like to keep only one of each view and instantiation should be happen only once. What am I doing wrong? (I'm using ARC.)
Thanks in advance!
You should not link your back button to the parent view controller. This is what causes the new instantiation.
The way to go is to embed the table view into UINavigationController (in IB, choose Editor -> Imbed In -> Navigation Controller. Then change your segue to a Push segue. You can of course hide the navigation bar etc. to make things look exactly as you like. Then, link the back button to the controller with an IBAction and in the handler do a simple
[self.navigationController popViewControllerAnimated:YES];
This would be the appropriate logic of what you are doing. Of course, you can also push the web view modally and then handle the button click with
[self dismissModalViewControllerAnimated:YES];
Hi there and thank you in advice for your help. I have a really strange problem while working with ViewControllers in Xcode4. First of all I have to say that I'm not using storyboards and I prefer to create any UI element programmatically. So I've set a UIButton and I want that, when pressed, it brings me to a new view controller. This is the code I'm using for a button:
-(void)settingsAndExportHandle:(UIButton *)buttonSender {
SettingsViewController* settingView = [[SettingsViewController alloc] initWithNibName:#"SettingsViewController" bundle:nil];
settingView.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:settingView animated:YES];
}
This buttons is initialized and allocated in the viewDidLoad method of the RootViewController. I want to switch to the other view controller (in this case SettingsViewController) when I press the button.
The strange thing is that when I press the button, the animation that flips the controllers goes well, but when it finishes I obtain the EXACT same things that I had on the RootViewControllers (same custom views, same buttons, same all!). The question is: what I'm missing?? I have to say that I use ARC (automatic reference counting) so I can't release or dealloc the views and buttons I've created on my RootViewController.
Any help will be appreciated. Thank you all!
Pushing and and modally presenting view controllers does not deallocate the view controller that presented them. It simply adds the additional view controller to the stack. You'll need to implement a callback method so that when the user hits the button to flip back to root view controller, your settings view controller lets the root view controller know what's about to happen so you can call a method you've written to reset the interface back to whatever state you need it at. You may also be able to use viewWillAppear: but that's a little messy.
However, according to the Apple Human Interface Guidelines, the user expects that when they push a view controller or modally present it, the view controller they were on will save state and be exactly the way they left it when they came back. It's disconcerting and annoying when state is not preserved while in a navigation controller context. It is especially annoying when it's modally presented.
Think about this - A user is in a hypothetical Mail app. They start typing out an email and set a font size and a color. They tap on the add attachment button, which brings up a modal view controller that allows them to select a picture. They select the picture and the modal view is dismissed, and in your implementation, the mail composing interface would have reset and the email content would be gone or at the very least the selected font size and color would be back to the default. That's not a good experience.
I am new to iOS and confused about the right way to implement UIPickerView.
I have a UITableView (the list of which is populated by XML File). Now I want to implement an option to trim down that list (say, show only type X or type Y). Now the confusion is, should I implement the PickerView in TableView itself, or make a new segue to show PickerView.
I tried implementing the first one but couldn't get it working.
A picker view wouldn't really fit inside a table view. You should have a button on the navigation bar or toolbar on your table view controller which presents a modal view controller holding your picker view.
This would then feed the selected value back to the table view controller (via a custom delegate protocol method, or similar) and the table view can filter its rows.
I have a simple iOS 5 storyboard that contains a tableview controller scene. However, the table UI takes up 100% of the real estate and I am unable to add any additional objects such as a title bar. Any object that I drag to the scene will try to size correctly and what-not but as soon as I let go it will not add the object. What am I doing wrong?
If all you want is a title bar, then it looks like you want to embed your table view controller in a navigation controller. You can do this by selecting your table view controller and using the Editor: Embed In: Navigation Controller menu command. Once you do this, you should have a navigation bar, and you can double click it to edit the title.
If you need arbitrary UI elements along with your table view, then I think you need to use a plain UIViewController scene instead of a UITableViewController, and manually drag a UITableView into the scene. Your view controller would not subclass UITableViewController, instead it would subclass UIViewController and implement the UITableViewControllerDelegate and UITableViewControllerDataSource protocols. Also, you would need to manually wire up the delegate and dataSource outlets by ctrl-dragging from the table view to your view controller in interface builder, and your view controller would need a custom tableView outlet that points to the UITableView and is correctly wired up in IB. Perhaps there is a simpler approach than this though, if someone has a better suggestion that would be great to hear.