I have a UIViewController and I am using the WEPopover controls to generate a drop-down on the view controller. The content for the WEPopover is held in a UITableViewController. The WEPopover is triggered when a UIImageView is pressed on the main UIViewController
WEPopover GitHub Link
I am aware that once a row in the table is selected the didSelectRowAtIndexPath triggers. Where I am facing a challenge is taking the result of the selected row, and then triggering a change on the main UIViewController.
What I am attempting to do is take the string in the row I have selected in the UITablewViewController, and then apply that string value (Hex String, using UIColor Extended from GitHub to convert to UIColor)as the new color overlay of the UIImageView which is located on the UIViewController
Simply you can define a delegate protocol for your UITableViewController, and a method, such as - (void) tableViewControllerDidChooseValue:(id)sender.
Make the main view controller conform to that protocol. Upon showing the UITableViewController, add the main view controller as the delegate for the UITableViewController.
Once didSelectRowAtIndexPath is called, call the delegate (main view controller)'s method with the updated value.
You may use this as a chance to dismiss the UITableViewController.
Related
My app header is currently a full width, 65pt height UIView which I then use as a generic header for all pages.
class AppHeader: UIView {
...
}
Then, in my Main.storyboard I have a UIViewController with a View from the object library which has its class specified as AppHeader.
My AppHeader (UIView) has multiple buttons which should, if clicked, take you to from the page/controller you're currently on to another.
From the AppHeader class I do not have access to use the present method to show another controller as its not within scope.
Here is my AppHeader.xib:
How can I resolve this?
This is very bad behaviour, you should not use a UIView as a header. You should add a Navigation View Controller as the first view controller of your app. Navigation view controller has the navigation bar where you can put the buttons you want there. From that ones, you will be able to push or present other view controllers.
Check the official documentation: https://developer.apple.com/library/content/documentation/WindowsViews/Conceptual/ViewControllerCatalog/Chapters/NavigationControllers.html
Make your AppHeader view a custom subclass of UIView if it isn't already. Wire the actions on the button to IBAction methods in the view.
Create a protocol AppHeaderDelegateProtocol. Give your AppHeader class a weak delegate property. Define methods in that protocol that let the AppHeader notify it's owning view controller about button presses.
Implement your AppHeaderDelegateProtocol in view controllers that will contain instances of AppHeader.
Connect the delegate property to each instance of AppHeader's owning view controller.
That should do it.
You can create a protocol - call it AppHeaderDelegate or something - and set up your other viewControllers to adopt that protocol. You could define functions to let your delegate know that a certain button was pressed, and your delegate viewController can react to that by presenting the correct view controller.
Apple's docs on protocols here.
Alternatively, you can use NotificationCenter to broadcast notifications to let subscribers know that a certain button was pressed, and have your viewControllers listening for these notifications and reacting to them accordingly. You have to manage when classes start/stop listening, though, as you may have several objects trying to react to a single notification.
I have TableViewController with a custom cells.
For table is responsible class:
#interface CustomTableViewController : UITableViewController
For cells is responsible class:
#interface CustomTableViewCell : UITableViewCell
The ImageView are located in cell of table.
How I can open new controller when I click(touch) at ImageView inside cells?
As it appears I must to use UIViewController near UITableViewCell that to open new viewController, is not?
Usually this kind of stuff is handled inside UITableViewDelegate method didSelectRowAtIndexPath. However the table view calls this method when the entire cell is tapped.
If you want to trigger the action only for the image, you might have to add UITapGesture to the image view. Do not forget that image views have userInteractionEnabled set to false by default. There are two ways to communicate the tap event to the view controller that i can think of right now. Either by delegation or closure. The latter one requires less code.
I'm writing an app that uses storyboarding and I want to update the labels in one view by clicking a button in a previous view.
_label.text = variable1;
is the line I would use to change the value of label, which is in the next view, when I click the button. Using this method I can easily change labels in the same view as the button but it does nothing when I go to the next view and see empty labels.
I've tried looking everywhere and found similar issues but couldn't find anything that worked for me so any solution would be very appreciated!
Unfortunately, it is not possible to connect IBOutlets between different scenes in storyboard.
It is difficult to suggest some precise solution because you have to provide more details about the setup which you have. Still, it is possible to outline some possible solutions:
Using prepareForSegue
If the view controller which you want to modify appears after the segue is performed you can customise its appearance in prepareForSegue function.
Using delegation
You can assign the view controller which wants to modify another view controller as its delegate. For example, if ViewController1 wants to modify ViewController2:
#interface ViewController1: UIViewController {}
#property (nonatomic,weak) ViewController2 *controllerThatIWantToModify;
with such setup you can call:
self.controllerThatIWantToModify.label.text = variable1;
You use storyboards, so there must be a segue from your first viewController (with the button) to your second (with labels in it).
If it is the case, you can set up the labels of the second view controller from the prepareForSegue method of your first view controller.
This method is called with a segue object which has a destinationViewController property which is your second view controller.
If you have several segue from this viewController, you should check if it is the right segue and then set it up.
To do that you need to set up outlets that gives you access to the labels from the viewController.
Then you can either write a setUpLabelsWith:(NSString)text1 ... method in your view controller, or directly access the outlets from the first view controller (supposing their are not private).
Yes this supposes your second view controller has a custom class.
I'm currently learning Objective-C by doing tutorials ("the iOS Apprecente")
Now I need to make a checklist
I added in viewController.h
#interface ViewController : UITableViewController
Normal there stands
#interface ViewController : UIViewController
The next is to go to Storyboard place there a TableViewController, give it the name: ChecklistsViewController (Identity inspector > Custom class > class.
I added a label into the first Table view cell. But when I run it there's nothing.
What to do?
Two separate issues here:
The choice of UIViewController with your own IBOutlet for the table view or a UITableViewController is simply a question of whether, in Interface Builder (IB), you added a standard view controller to which you added a table view, or whether you used a table view controller. You use the former if you have other controls on the view in addition to the table view. You'd generally use the latter if the table view is the only thing being presented in that view controller's view. Bottom line, your choice of UIViewController or UITableViewController is dictated by how you added the scene in IB. From your description, it sounds like you went down the UITableViewController approach, which is fine.
In terms of why you're not seeing anything, there are a bunch of possible reasons:
Did you specify the cell identifier for your table view cell prototype? Is it the same identifier you're using in cellForRowAtIndexPath method?
If you manually added a table view to a standard view controller's view, did you specify the view controller as the delegate and dataSource for the table view? Also, did you create an IBOutlet for the table view itself, hooking that up in IB? (If you used a table view controller in Interface Builder, you don't have to do these steps.)
You might want to double-check that the base class for the table view controller was correctly set in IB.
Did you implement all of the UITableViewDataSource methods, notably numberOfRowsInSection? If you don't do that, it will conclude that there are no rows, and no cells will be generated.
You say that you specified the base class for your view controller in IB to be ChecklistsViewController. But in your code snippets, it looks like you're using a custom class called ViewController. Make sure you're using the same UITableViewController subclass for both.
Very new to iOS coding. I'd like to be able to display a modal dialog from inside a UIButton subclass. I've used presentModalViewController from inside a UIViewController before. How would I grab a reference to a UIViewController from my subclassed UIButton?
Can I somehow discover it's parent? Implement a protocol in the parent UIViewController that I can set as a delegate on my UIButton subclass?
You should be able to use any subclassed UIButton just as a normal UIButton. Setup an action that is triggered on the button which will call a method on the view controller. The view controller will deal with pushing the modal view controller.
Although there are ways in which you can find out the view controller from the button when it is attached to a view, this is a better approach.