Forgive me if this has been asked/answered already but I couldn't find it anywhere (at least no in Monotouch - vaguely answer for ObjC. So completely new to Monotouch but I have everything completed in my application that I want with one exception. I'm trying to update a parent of a subview.
Here is the scenario:
I have a UINavigationController with a UIView (not a table) which has a few buttons on it that directs via a PushViewController to a Subview. I make some changes on the subview, which I would like reflected back on the parent. I can of course add a manual refresh button if I wanted but was looking for something a little better.
I did see some things that referred to using a viewWillAppear but couldn't find any good examples. My attempts failed pretty bad, so any suggestions would be great.
Thanks,
Richard
If you have a UINavigationController, it has a "back" button on top. Once this is hit by the user (or if you pop to a previous view controller), the currently view controller shown will trigger ViewWillDisappear and ViewDidDisappear and the view below (the one with your buttons) will fire ViewWillAppear and ViewDidAppear. Just overload those and update your UI state in there.
Related
I followed this link http://www.wintellect.com/devcenter/jprosise/handling-the-back-button-in-windows-10-uwp-apps and "successfully" make my button work. I mean I can make my backbutton work between pages. However, if I navigate to a control which is inside this page and will cover the whole screen, then it would not allow me to back to the page. I will stuck in that control.
I'm wondering how to solve this problem. Currently I can think two possible ways (0) Override OnBackRequested() inside the control's code behind or viewmodel? (1) Override OnHardwareButtonsBackPressed() inside the control's code behind or viewmodel?. I don't know if these are correct way to do it or there is some better way to do it. Another reason for me to override is that I need to make some changes to the page navigation behavior.
As you have guessed, you simply need to hide the control again when the back button is pressed or back is requested in some other way. I would listen for the BackRequested event (not the HardwareButtons.BackPressed event) in the page's code-behind, and in the handling method you can check to see if the control is currently shown. The reason I recommend the BackRequested event is because it is universal, while HardwareButtons.BackPressed only works on a phone. Anyway, if the control is visible, then hide it, and set the Handled property of the event arguments to true. If the control is already hidden, don't do anything special to handle the event (because in that case you will want the navigation system to handle it by navigating to the previous page, if there is one). There are many aspects to navigation in Windows 10 -- please see these pages on Navigation and the SystemNavigationManager.
I've currently got two view controllers A and B, A uses a segue to push B and this works back and forth nicely, however based on some button presses in view controller B i want to change the text within a UITextView in controller A.
I've had a look at previous posts but i'm a novice at present and was confused by the way in which i should go about doing this.
I'd love to be able to get my head around how interactions are best done between various parts of the app. Also i was wondering if there is a way i can tap into a segue returning to trigger some other code.
Thanks
Edit:
OK perhaps i was a little bit limited with my information, from what i can gather reading other posts they are manually creating a variable for the viewcontroller (A) in viewcontroller (B) then accessing it in the second view controller (B) and setting a variable (property and synthesize) to edit that way, however i have the viewcontrollers embedded in a navigation controller and using a push setup in the storyboard (GUI system). I'm not sure if i have to create a variable to do this or if because they exist in the storyboard there is another way, if someone could just point me in the direction of a post that helps to explain this (i am looking at the moment too) i'd be very grateful.
OK well here's how i got it to work but i imagine there are:
A: Better ways to do it.
B: Changes depending on your setup.
I had my two view controllers embedded in a navigation controller, and used a segue push to access the second view controller each had a different class (all setup in the storyboard thing).
To get it working for me i did the following:
I have a singleton (a class that stores all my data but is global to the app so the variables can be accessed from anywhere in the app) this allows me to have variables that i can access from any view controller. A great tutorial on this can be found here
I then created an NSString variable (passedNote) and updated the value of this variable from the ViewController B, when my button was pressed.
Next when viewController A is loaded (in the viewWillAppear: (BOOL)animated method) i append or replace the value of the textview (dependent on some logic) I have with the global variable (passedNote).
Hope this helps anyone who had the problem.
I have a problem that I've been sitting with all the day. I have a super view which contains UIPageControl and UIScrollView, in this super view. I have created a sub view which contains three images, three labels, and three buttons. Each button has a touch up event. When the button event is triggered the super view will be promoted by a new view. For doing that, I created a segue which connected with super view and new view. Here is the connection code in the super view.
`
<connections>
<outlet property="pageControl" destination="ivy-0Q-UQo" id="rGm-sh-mdE"/>
<outlet property="scrollView" destination="4Yu-Qb-kbF" id="aqY-ou-cv4"/>
<segue destination="zZo-CH-P2Y" kind="push" id="xBU-ZO-u7s"/>
</connections>
`
This piece of code will guarantee the connection between the super view and the new view is okay,
here is the touch up event code.
WelcomeFrameViewController *welcomeFrameVC = [WelcomeFrameViewController alloc]; //super view instance
NSLog(#"=======================");
[welcomeFrameVC performSegueWithIdentifier: #"ForwardToLogin" sender: self];
When I run the program, the compiler complains with
2012-08-20 10:17:02.325 TTRen[2440:f803] ============44===========
2012-08-20 10:17:02.352 TTRen[2440:f803] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Receiver WelcomeFrameViewController: 0x688e960 has no segue with identifier 'ForwardToLogin''
I am quite new in iOS, any suggestions will be deeply appreciated.
'Receiver WelcomeFrameViewController: 0x688e960 has no segue with
identifier 'ForwardToLogin''
In your storyboard, check that you actually have a segue named "ForwardToLogin"
There does seem to be a bug with xCode (still in 6) where storyboard changes you make aren't get copied to the simulator. You can reset the Simulator's Content & Settings to resolve this.
Other things to check:
Check the naming of your segue. Check it again. Check it some more :-)
Ensure that your segue is pointing in the right direction. It needs to point away from the UIViewController that calls performSegue….
Ensure you don't have two copies of your view controller on top of each other, with the segue attached to the one on top, and you instantiating the one underneath!
There's a similar question here and I encountered the same problem too. The reset fixed it for me.
This is what I want to do but not sure if it could be done.
my first view contains 3 buttons.
When this view is displayed, I need to present a ModalPopup for the login.
When the authenfication is done, the user can tap on one of the 3 buttons.
When the button is taped, I need to switch this view to a TabBarController and active the correct TabBarItem regarding the button.
Most of the TabBarItems can contain a SplitViewController.
I read several posts and tutorial about the SplitViewController but most of them show how to run a splitViewController from the appDelegate controller.
Then my first question would be.. is it possible :-)
The second one, would be, how?
Thanks...
Mortoc is correct about UISplitViewController needing to be the root controller.
You can use MGSplitViewController as a drop-in replacement for UISplitViewController - and it doesn't have this limitation.
It sounds as if your hierarchy might be something like
UINavigationController (root)
UIViewController (3 buttons)
UITabBarController
MGSplitViewController (1)
MGSplitViewController (n)
Sorry, you'll have to roll your own SplitViewController equivalent. Apple only supports UISplitViewController as the root view item: it has to be the first view loaded in your application and it's size is fixed.
http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/iPadControllers/iPadControllers.html
my question is about view controllers, delegates and all that in general. I feel perfectly comfortable with UIView, UIViewController, Delegates and Sources, like UITableView does for instance. It all makes sense.
Now I have implemented my first real custom view. No XIBs involved. It is an autocomplete address picker very much like in the Mail application. It creates those blue buttons whenever a recipient is added and has all the keyboard support like the original.
It subclasses UIView. There is no controller, no delegate, no source. I wonder if I should have either one of those? Or all, to make it a clean implementation.
I just cannot put my finger on the sense a view controller would make in my case. My custom view acts much like a control and a UIButton doesn't have a controller either.
What would it control in my view's case?
Some of my thoughts:
For the source: currently the view has a property "PossibleAutocompleteRecipients" which contains the addresses it autocompletes. I guess this would be a candidate for a "source" implementation. But is that really worth it? I would rather pass the controller to the view and put the property into the controller.
The selected recipients can be retrieved using a "SelectedRecipients" property. But views should not store values, I learned. Where would that go? Into the controller?
What about all the properties like "AllowSelectionFromAddressBook"? Again, if I compare with UIButton, these properties are similar to the button's "Secure" property. So they are allowed to be in the view.
The delegate could have methods like "WillAddRecipient", "WillRemoveRecipient" and so on and the user could return TRUE/FALSE to prevent the action from happening. Correct?
Should I maybe inherit from UIControl in the first place and not from UIView?
And last but not least: my custom view rotates perfectly if the device is rotated. Why don't all views? Why do some need a controller which implements ShouldAutoRotateToDeviceOrientation()?
Does it make sense what I wrote above? In the end I will provide the source on my website because it took me some time to implement it and I would like to share it as I have not found a similar implementaion of the Mail-App-like autocomplete control in MonoTouch.
I just want to learn and understand as much as possible and include it in the source.
René
I can answer part of your question.
I just cannot put my finger on the
sense a view controller would make in
my case
The ViewController is responsible for handling the View's state transitions (load, appear, rotate, etc) These transitions are used mainly when you use a navigation component (UINavigationViewController, UITabBarController). These components needs to received a ViewController that will handles the view's transitions.
For exemple, when you push a ViewController on a UINavigationViewController, it will cause the ViewDidLoad, ViewWillAppear, ViewDidAppear. It will also cause the ViewWillDisappear, ViewDidDisappear of the current ViewController.
So, if your application has only one portrait view, you don't need a ViewController. You can add your custom view as a subview of the main window.