I am a new learner, I am doing an assignment, stuck on this point. My target is when user click on a cell inside collection view, I have to go on table view and pass data to it (Which means that table view will have only one cell with data for selected collection view item).
I know I will go to table view programatically not possible through storyboard(If possible let me know) by using delegate method didSelectItemAtIndexPath
Can you explain the way to open table view from collection view cell click and how I will wrap data to pass to other controller (I think Segue? But how if we cannot use storyBoard). I am not getting clear there is no much help on internet in objective c? If you provide some pathway it will be good and if you explain it would be excellent??? Any helping material will be a plus
I am using XCode11 with objective c and not using XIB files Just working by storyboards
I also think segues is the way to solve your problem.
Set up the segue in storyboard and then inside the didSelectItemAtIndexPath set some variable with the data you want to pass and use performSegueWithIdentifier:sender to kick off the segue. Then override prepareForSegue:sender to transfer this data to the destinationViewController. You could use the sender to transfer the data from perform... to prepare... as well but I suggest for now just use some instance variable.
Related
I want to find out what ViewController a custom Table View Cell is located on. I'm using the UI Hierarchy inspector and I don't see the name of the View Controller, it just says UITableView as the super view of the cell.
Is there a definitive way to inspect a cell and find out what View it appears on top of? If I can't do this in the UIHierachy Inspector, how can I do this?
You can achieve this using Associative References. They are not pretty, and not easy to use but effective on being able to associate an object with another.
Here is a link to a tutorial on how they work.
Associative References
After digesting this you can plan to associate the view controller / view to the tableview cell on iteration (cell for row at index path maybe)
and delegate method did select row at index path you would be able to obtain the associative reference and know what view controller needs to be manipulated.
Sometimes IB simply doesn't allow you to add a view as a subview to a UIViewController as illustrated here
If I drag a UIViewController from the object library and try to embed it within Mailbox View Controller.. it doesn't highlight, however it would work fine if I try to add it to the generic View Controller at the bottom (can the fact that Mailbox View Controller have a Customer Class MailboxViewController have anything to do with it?)
I'm pretty sure I can do this programmatically (which is what I'll try next) but I was wondering if there was a reason for this (and if there was a way around it).
update:
this is what i'm trying to accomplish: I was following the steps here to implement a segmented view controller below search bar like in the iphone mail app.. however I kept on getting an error saying that a view can only belong to one view controller at a time.. So what I'm trying to do is basically create a separate viewcontroller, reference it from MailboxViewController as an outlet, make the containing view of my search area the view of this new view controller (this is where i'm getting stuck) and finally make the searchContentsController property of UISearchDisplayController refer to the view of this new view controller. (if this sounds confusing, which I know it does, please refer to this answer)
From your screenshot, the view property of your mailbox view controller is a table view.
A table view in interface builder won't support the dropping of arbitrary views onto it as subviews - where would it put them at runtime? In IB the table has no content, it just has that visual representation of cells to let you know what it is.
You haven't said what you are trying to set up so I can't offer any additional help. Adding a subview programmatically to a table view probably won't give you the effect you're after either - a table view is a UIScrollView subclass, so your new view will either move off screen or get covered up by the table view adding cells.
This might be a very basic question, but I could not find the answer yet.
I have a UITableView that acts as a menu for my app. Each row on the table view, when selected, opens a different subclass of UIViewController.
At the moment my code works the same way used in the UICatlog example from Apple.
In the main view controller (the table view), each menu item is described in a dictionary in an array (menuList). Each dictionary contains an instance of the UIViewController subclass for that screen and other data about the menu item. When the user selects a row, the didSelectRow atIndexPath kicks in and calls the appropriate view controller, stored in the dictionary at that indexPath.row of the menuList array.
It seems to be very wasteful to alloc and init every single view controller when the table view first loads.
My question is: Is there a better way than the one demonstrated in UICatalog to alloc/init my view controller sublasses only when the associated row is tapped?
(I know I can use a complex if..else structure in the didSelectRow, but this results in an extremely long didSelectRow method and breaks encapsulation. I wonder if there is a cleaner way to do this, allocing and initing the appropriate view controller based on data from the dictionaries)
user1349768 try to use Storyboard, but this feature only works in iOs 4 and higher.
Just a suggestion ... put some reference to each view controller into NSArray and then initiate and segue to them when the row gets tapped on (and just get the reference from objectAtIndex:).
Although I could not find a better way to do this, the memory signature of each allocated View Controller is only 288 bytes. Since the solution suggested by apple is a lot more elegant and scalable then using a switch case statement, I left it as it is.
I've got a custom UITableViewCell that allows a user to input text when in edit mode. I've noticed that on stock UITableViewCells, when I swipe left, then hit the Delete button, it's table view receives the commitEditingStyle:forRowAtIndexPath message. I'm curious where this message is coming from. As far as I can tell, individual cells don't have a reference to the table view they belong to. If I want my custom cell to send this message, how would I go about doing that? I've thought about using the superview of the cell, but it seems like there's got to be an easier way.
This method gets called automatically (if you implement the data source protocol) before adding any row or column.
If you want to know to which table view a cell is belonging, use the superview method.
I've created a window that contains an NSSplitView in which case the right custom view has a view that I swap into at runtime. The custom view swapped in contains a NSTableView with data inside it. I have a search box in the main window of the application that I want to be able to constrain the rows of the table view with.
I have the code to do this and I know it works, but the code I have was tested with a search text box and table view that were on the same window scope. With the text search box now being in the main window and the table view being in a different custom view, I'm not sure how to get the text search box to call the relevant methods from the custom view's controller class, because I don't have direct access to these method anymore.
I'm sure this is a very beginner question, but any help would be appreciated. Thanks.
Have your main window controller pass the search query or filter predicate to a property of the content view controller.
You can give the main window controller a weak-referencing (assign) property that holds the current content view controller. Implement a custom setter that not only assigns to the backing instance variable, but also does the swap. That, any time it's time to do a swap, you simply say self.currentContentViewController = viewControllerToSwapIn, and when it's time to change the query/predicate, you pass it to self.currentContentViewController.searchQuery (having implemented the searchQuery property in the MainContentViewController class and made all your actual content-view controllers inherit from that class).