In my xib, I set the reuse identifier of the cell to A
but then in -registerNib:forCellReuseIdentifier: I declare "B"
[self.tableView registerNib:[UINib nibWithNibName:#"A" bundle:nil]
forCellReuseIdentifier:#"B"];
what are the effects of such behaviour? all looks running ok, why there are 2 places to enter the reuse identifier?
You can safely ignore the reuseIdentifier field in the xib.
Because that option is actually pretty useless when you are dealing with xibs. It's probably there just because Xcode uses the exact same User Interface as it uses when editing storyboards.
Compared to storyboard, in xibs there is no connection between the cell and the tableView. The cell is even stored in a different file. So the cell won't, and can't be dequeued/created with its reuseIdentifier.
If you have a cell in a xib you have to register it in code. This process creates the connection between the tableView and the cell (or its xib).
Related
Im using the Storyboard to create my UI.
I have a SplitViewController. The MasterViewController holds a TableViewController where I created a CustomCell with Custom Design.
The Cells are shown pretty good with my data.
The point is: The Custom Cell also holds an Info-Button, with should Popup a little 300x88 TableViewController with some data.
If the Cells in my MasterViewController->TableViewController where a Static one, I just would drag & drop a Segue from the Info-Button to my Popup-TableViewController.
But sadly I cant do this with a dynamic Prototype Cell... I just get the error:
Couldn't compile connections ... >> anchor >> UIButton...
So how can I implement this?
Kind Regards.
Define a manual segue dragging the whole master view onto the detail view, then add a manual target/action to your custom info button and perform the manual segue there. Of course you must set a segue identifier in the storyboard to later reference it in the code, IB will tell you if you forget to.
Instead of connecting and creating segue from individual cells, you can connect all those segues from the View Controller button, lying below your view in your storyboard. In this case, you will have multiple segues and none of them will be individually connected to cells. And when segues are ready, you can use this method for moving on to the next View Controller depending on which cell is tapped from the tableView.
[self performSegueWithIdentifier:#"yourSegue" sender:nil];
You just have to check which cell is tapped and then perform the appropriate Segue on tap using the above code and the respective segue identifier. The prepareForSegue method will be called immediately after this method is called.
Look out for the yellow button as shown below your View Screen in your storyboard.
Drag and drop a segue from that button onto the View Controller that you want to connect.
Hope this helps.
So I have this UITableViewCell subclass that has some really complicated logics in it - it triggers some actions in UIViewController it's actually attached to. Of course the cell is not aware of its UIViewController but I still navigate to it like this:
UITabBarController *tabVC = (UITabBarController *)appDelegate.rootVC.centerPanel;
SGFirstTabViewController *firstTab1 = [tabVC.viewControllers firstObject];
[firstTab1 reloadCell:self];
The thing is now that I want to use the same subclass of UITableViewCell around about 5 different UIViewControllers.
What's the best way to do this? I will almost never know what is the UITableViewCell's VC is and I simply can't create 5 different cell subclasses with the same code over and over. What's the best way around it?
I think there is perhaps some misunderstanding in the role of the cell in the model-view-controller programming pattern.
The cell should not reload itself but it should be told to reload by the view controller that controls it. The reload code in the cell can stay the same.
So, rather than the cell having to find out which one its view controller is, have the view controller listen to the cell action (e.g. via delegate methods) and fill it with the appropriate reload data as directed.
Have couple of questions
When I place a UITableViewController on the storyboard, and wish to work with static cells must I create a class deriving from UITableViewController or can I only create a class deriving from UITableViewCell for the custom cell?
I created a custom UITableViewCell placed number of controls on it and tried dragging with control pressed to create an outlet but couldn't, any ideas why?
If I wish each cell to have different controls and behavior can I set each cell a different custom UITableViewCell and if so how does the UITableViewController initialize it? do I need to load it programmatically?
1) The cell must be a subclass of UITableViewCell.
2) No, I don't know why that didn't work, it should. Where were you trying to make the connection to? The cell or the table view controller?
3) Yes, I think this is the best way to do it. Have a different custom cell class for each different kind of cell, and make IBOutlets from the custom cell to its controls. Then just make one IBOutlet from the table view controller to the cell itself (you can then refer to the controls with something like self.cellType1.label1 ...). You don't need to do anything to initialize the cells if they're made in the storyboard.
Struggling to find where fault is with my code. On first view load, everything works and loads fine as it should, but when i revisit that view, it seems that the first two cells are empty. I logged the dictionary (dict) in viewWillAppear: and it logs the data fine, so error has to be in cellForRow method. Take a look at my method, and see where i'm going wrong, the third cell populate third piece of data, so i'm totally stumped, but the first two cells are completely blank, no data.
http://pastebin.com/Va84MG5g
First of all, why are you doing all of that insane UITableViewCell customization inside of your tableView:cellForRowAtIndexPath: method? Create a custom UITableViewCell subclass and do the set up there.
In the class's initWithStyle: method, add all of your subviews with a frame of CGRectZero, because at initialization, the table view cell doesn't know how big it is. You can set text alignments, colors, etc. here as well. Then, in layoutSubviews, go ahead and set all the frames. Override prepareForReuse and set things like your UIImageViews to nil. This will help with performance for reused cells.
As for why you're not seeing your data in your first two cells, my initial thought is that it has something to do with the way you're setting up your cells for reuse. You're asking your tableView to dequeue a regular UITableViewCell and only creating all of these subviews if the returned cell is nil. So what happens when it returns a UITableViewCell? You skip the part where you alloc/init all these subviews, and so you're basically adding nothing to the cell. I feel if you create a custom subclass and ask your UITableView to dequeue that instead, you'll get the result you're looking for.
NOTE: If you're targeting at least iOS 5, you can create your UITableViewCell's layout in a nib and register the nib with the table view. Doing so will guarantee that you always get a dequeued cell, and you never have to do your if (cell == nil) check. If you're targeting iOS 6, you can register a UITableViewCell subclass.
I'm trying to do something very simple: set up a segue so that when you click on a cell in a table it will take you to another View Controller. The problem, I believe, originates from the fact that the TableView these cells are in is embedded in a regular ViewController (as opposed to a TableViewController), and is one of two subviews in this ViewController.
As far as I can tell, I've set everything up correctly: I embedded the ViewController with the two subviews in a Navigation Contoller, set it to be the dataSource and delegate for the TableView, and created a push segue from a TableViewCell to my second View Controller in the storyboard. However, when the app is run and a user clicks a row in the table, it merely selects the row and the segue doesn't fire at all (I've debugged it and the prepareForSegue function isn't even being called).
Is there something I'm missing here? Or is this for some reason not possible if the TableView is not the only view in its view controller?
I find that if I had recently wired the segue from the cell's accessory view, and later delete the segue and try to wire a new segue to the cell directly it does not work (using Xcode 4.6.2) -- Xcode keeps connecting the segue to the accessory view (even if there isn't one)! The way I fixed it is by selecting the cell in IB and using the connection inspector to (1) delete the original "accessory action" segue and (2) directly wire the "selection" segue by dragging from the filled circle in the image below to the appropriate destination view controller.
This may or may not help you, but I ran into this issue because I had defined two different cell types, and had provided didSelectRowAtIndexPath implementation. I had to add [self performSegueWithIdentifier:#"Whatever" sender:self] as part of didSelectRowAtIndexPath and the issue got resolved.
If you are able to at least detect row selections, you may be able to take advantage of this method.
If you have customized the cell rendering, e.g.:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
then ensure you are using the same cell identifier as specified for the prototype cell in ste story.
So in this case the 'Identifier' of the cell which hooked up the segue should be set to 'Cell'.
If you are creating the StoryBoard in Xcode then do the following:
Create a UITableViewController
Add a prototype UITableViewCell
Create the UIViewController that will be your segue target.
Control-Click on the prototype UITableViewCell and drag to the segue target.
That's it. You'll probably want to edit the characteristics of the UITableViewCell to be, for example, your subclass of UITableViewCell.
I had the similar issue.
Fix is
1. Write SegueIdentifier for the segue in Storyboard
2. Add the following line [self performSegueWithIdentifier:#"SegueIdentifier" sender:nil]; in didSelectRowAtIndexPath.
I hope this would help.
Had the same problem. Segue from a prototype table view cell inside a regular View Controller would make the app crash. In case someone have the same problem.
My solution:
If you are using a push segue make sure your first View Controller with the table view is embedded in a Navigation Controller otherwise "push segues" wont work. Also point the segue at the destination View Controller, not its Navigation Controller!
And as mentioned earlier, make sure your "segue identifiers" are correct.
at "didSelectRowAtIndexPath" I call "[self performSegueWithIdentifier:#"Your_destination_View_Controller" sender:self];