I am making a custom ui table view cell. I know i can use loadNibNamed method to use .xib
of the cell but that causes scrolling to be slow when my I have too much data in it .
I want to use UI nib because its lot faster than loadNibNamed method for loading custom cell .xib file .
static NSString *cellIdentifier = #"PostStreamCell";
PostStreamCell *cell= [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil)
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"PostStreamCell" owner:self options:nil];
cell = [nib objectAtIndex:0];
UINib *cellNib = [UINib nibWithNibName:#"MemberCell" bundle:nil];
[cell.collectionView registerNib:cellNib forCellWithReuseIdentifier:#"MemberCell"];
}
cell.textlabel.text =#"xyzabc123";
I tried using code below in above "if "block but failed to use it. Any help would be appreciated.
UINib *cellNib = [UINib nibWithNibName:#"PostStreamCell" bundle:nil];
[cell registerNib:cellNib forCellWithReuseIdentifier:#"PostStreamCell"];
Create your xib file with a UITableViewCell as the top-level object. This is called Cell.xib
Create a UINib object based on this file
Register the UINib with the table view (typically in viewDidLoad of your table view controller subclass).
use the following line in viewDidLoad:
[self.tableView registerNib:[UINib nibWithNibName:#"Cell" bundle:nil] forCellReuseIdentifier:#"Cell"];
Then, in cellForRowAtIndexPath, if you want one of the cells from the nib, you dequeue it:
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell"];
This either creates a new instance from the nib, or dequeues an existing cell.
You only need to register the Xib once, so this regiserNib code should go within the viewDidLoad method of your class file
UINib *cellNib = [UINib nibWithNibName:#"PostStreamCell" bundle:nil];
[self.tablview registerNib:cellNib forCellWithReuseIdentifier:#"PostStreamCell"];
Then within your cellForRowAtIndexPath method of your tableview
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *cellIdentifier = #"PostStreamCell";
PostStreamCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath];
cell.textlabel.text =#"xyzabc123";
}
This will work for you as you need it.
Cheers
Edit in response to PostStreamCell error*
Please make sure your custom UITableViewCell xib has the 'PostStreamCell' identifier, which you can set in this part of the IB
Please note the xib is a UITableViewCell object.
Update - pic showing where to check custom class files associated with xib
Within the Utilities of the IB, please make sure your custom UITableViewCell uses your custom class files PostStreamCell. Please check they're shown in this part of the IB.
Also within your UIViewController class files, (where you have the UITableView methods etc) make sure to
#import "PostStreamCell.h"
I've read all the relevant other questions on this topic and tried the fixes, none of which have worked. My app crashes/hangs to the extent that I have to force quit Xcode in order to restart working, when dequeueReusableCellWithIdentifier: is called.
It makes no difference if I use dequeueReusableCellWithIdentifier:, or dequeueReusableCellWithIdentifier:forIndexPath: , and I HAVE set the class with registerClass:forCellReuseIdentifier: , as you can see in the code below.
Registering the class in my ViewController:
#implementation LWSFlavourMatchesViewController
-(void)viewDidLoad
{
[super viewDidLoad];
_flavourMatchesView = [LWSFlavourMatchesView flavourMatchesViewWithDataSource:self.flavourMatchesDataSource andDelegate:self.flavourMatchesDelegate];
self.tableView = _flavourMatchesView;
[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:#"flavourCell"];
}
And trying to dequeue cell in tableView:cellForRowAtIndexPath in my dataSource:
#implementation LWSFlavourMatchesDataSource
// other methods...
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *flavourCellIdentifier = #"flavourCell";
NSString *currentSelectedFlavour = [self.flavourWheel selectedFlavour];
UITableViewCell *tableViewCell = [tableView dequeueReusableCellWithIdentifier:flavourCellIdentifier forIndexPath:indexPath];
if(tableViewCell == nil)
{
tableViewCell = [[UITableViewCell alloc ]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:flavourCellIdentifier];
}
[tableViewCell.textLabel setText: currentSelectedFlavour];
return tableViewCell;
// return [UITableViewCell new];
}
If I remove all other code but un-comment out return [UITableViewCell new]; then the app does not crash. What is it about my dequeuing that is causing this problem?!
I refactored your tableview delegate. You do not need to check if the cell is nil because you registered the class with [self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:#"flavourCell"];.
I made your cellIdentifier static. But to remove the duplication on the registerClass function may you make a #define REUSE_IDENTIFIER #"flavourCell".
If this is still slow, than is the [self.flavourWheel selectedFlavour]; the cause. Check out the instruments tutorial for performance improvements: http://www.raywenderlich.com/23037/how-to-use-instruments-in-xcode
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *flavourCellIdentifier = #"flavourCell";
NSString *currentSelectedFlavour = [self.flavourWheel selectedFlavour];
UITableViewCell *tableViewCell = [tableView dequeueReusableCellWithIdentifier:flavourCellIdentifier forIndexPath:indexPath];
[tableViewCell.textLabel setText: currentSelectedFlavour];
return tableViewCell;
}
try removing the class registration:
[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:#"flavourCell"];
You shouldn't need to register the class if you are instantiating a generic UITableViewCell class cell from a storyboard
Another cause for this error can be-
invalid nib registered for identifier (Cell) - nib must contain exactly one top level object which must be a UICollectionReusableView instance
I had a UIView in my xib instead of a collectionViewCell. Of course, if you have multiple top level objects in the .xib, the same crash will show. Hope this helps.
Take care that if your cell is an object in a XIB, and you are using something like :
[self.tableView registerNib:[UINib nibWithNibName:#"cell_class_name" bundle:nil] forCellReuseIdentifier:#"cell_reuse_name"];
to register the cell, be sure the identifier in the attributes inspector in Interface Builder is correct, in this case #"cell_reuse_name".
If the identifier isn't the same, you may be stuck with an odd situation where creating new cells from the nib each time, i.e.
NSArray *objects = [bundle loadNibNamed:#"cell_nib_name"
owner:nil
options:nil];
cell = (UITableViewCell *)[objects safeObjectAtIndex:0];
seems to work fine, but trying to use
[tableView dequeueReusableCellWithIdentifier:#"cell_reuse_name"];
crashes.
In practice it's often easiest to use the same name for the XIB, custom class, and reuse identifier. Then if there are issues, you can just make sure they are all the same.
I had completely different issue. Mismatch between String/XIB based localization. It did help to enable/disable+remove unneeded localizations.
Try this:
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"NIB_NAME" owner:self options:nil];
If it hangs, there's something wrong with your XIB (like in my case).
Try this:
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:nil];
if (cell == nil) { cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"flavourCellIdentifier"]; }
In my UITableViewController subclass, I register my cell class as follows:
[[self fieldListTableView] registerClass:[MyCellClass class] forCellReuseIdentifier:#"MyCellIdentifier"];
I then dequeue the cell using the method introduced in iOS 6:
MyCellClass* cell = (MyCellClass *)[tableView dequeueReusableCellWithIdentifier:#"MyCellIdentifier" forIndexPath:indexPath];
However the cell's xib file seems to be missing. When I run po cell in lldb, I get a valid looking cell object. Then when I try po [cell myLabelOutlet], I get a nil in response.
Do I need to register the XIB file too?
To load cells from a xib file, you have to register it with registerNib:, not with
registerClass:. Example:
[self.fieldListTableView registerNib:[UINib nibWithNibName:#"MyCellClass" bundle:nil]
forCellReuseIdentifier:#"MyCellIdentifier"];
So I was making an rss reader for my school and finished the code. I ran the test and it gave me that error. Here is the code it's referring to:
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell =
[tableView dequeueReusableCellWithIdentifier:CellIdentifier
forIndexPath:indexPath];
if (cell == nil) {
cell =
[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:CellIdentifier];
}
here's the error in the output:
2012-10-04 20:13:05.356 Reader[4390:c07] * Assertion failure in
-[UITableView dequeueReusableCellWithIdentifier:forIndexPath:], /SourceCache/UIKit_Sim/UIKit-2372/UITableView.m:4460 2012-10-04
20:13:05.357 Reader[4390:c07] * Terminating app due to uncaught
exception 'NSInternalInconsistencyException', reason: 'unable to
dequeue a cell with identifier Cell - must register a nib or a class
for the identifier or connect a prototype cell in a storyboard'
* First throw call stack: (0x1c91012 0x10cee7e 0x1c90e78 0xb64f35 0xc7d14 0x39ff 0xd0f4b 0xd101f 0xb980b 0xca19b 0x6692d 0x10e26b0
0x228dfc0 0x228233c 0x228deaf 0x1058cd 0x4e1a6 0x4ccbf 0x4cbd9 0x4be34
0x4bc6e 0x4ca29 0x4f922 0xf9fec 0x46bc4 0x47311 0x2cf3 0x137b7 0x13da7
0x14fab 0x26315 0x2724b 0x18cf8 0x1becdf9 0x1becad0 0x1c06bf5
0x1c06962 0x1c37bb6 0x1c36f44 0x1c36e1b 0x147da 0x1665c 0x2a02 0x2935)
libc++abi.dylib: terminate called throwing an exception
and here's the code it shows in the error screen:
int main(int argc, char *argv[])
{
#autoreleasepool {
return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
}
}
please help!
You're using the dequeueReusableCellWithIdentifier:forIndexPath: method. The documentation for that method says this:
Important: You must register a class or nib file using the registerNib:forCellReuseIdentifier: or registerClass:forCellReuseIdentifier: method before calling this method.
You didn't register a nib or a class for the reuse identifier "Cell".
Looking at your code, you seem to expect the dequeue method to return nil if it doesn't have a cell to give you. You need to use the dequeueReusableCellWithIdentifier: for that behavior:
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
Notice that dequeueReusableCellWithIdentifier: and dequeueReusableCellWithIdentifier:forIndexPath: are different methods. See doc for the former and the latter.
If you want to understand why you'd want to ever use dequeueReusableCellWithIdentifier:forIndexPath:, check out this Q&A.
I think this error is about registering your nib or class for the identifier.
So that you may keep what you are doing in your tableView:cellForRowAtIndexPath function and just add code below into your viewDidLoad:
[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:#"Cell"];
It's worked for me. Hope it may help.
Although this question is fairly old, there is another possibility:
If you are using Storyboards, you simply have to set the CellIdentifier in the Storyboard.
So if your CellIdentifier is "Cell", just set the "Identifier" property:
Make sure to clean your build after doing so. XCode sometimes has some issues with Storyboard updates
i had the same problem replacing with
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell==nil) {
cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
solved
The problem is most likely because you config custom UITableViewCell in storyboard but you do not use storyboard to instantiate your UITableViewController which uses this UITableViewCell. For example, in MainStoryboard, you have a UITableViewController subclass called MyTableViewController and have a custom dynamic UITableViewCell called MyTableViewCell with identifier id "MyCell".
If you create your custom UITableViewController like this:
MyTableViewController *myTableViewController = [[MyTableViewController alloc] init];
It will not automatically register your custom tableviewcell for you. You have to manually register it.
But if you use storyboard to instantiate MyTableViewController, like this:
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
MyTableViewController *myTableViewController = [storyboard instantiateViewControllerWithIdentifier:#"MyTableViewController"];
Nice thing happens! UITableViewController will automatically register your custom tableview cell that you define in storyboard for you.
In your delegate method "cellForRowAtIndexPath", you can create you table view cell like this :
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"MyCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
//Configure your cell here ...
return cell;
}
dequeueReusableCellWithIdentifier will automatically create new cell for you if there is not reusable cell available in the recycling queue.
Then you are done!
I'll just add that Xcode 4.5 includes the new dequeueReusableCellWithIdentifier:forIndexPath:
in its default template code - a potential gotcha for developers expecting the older dequeueReusableCellWithIdentifier: method.
Swift 2.0 solution:
You need to go into your Attribute Inspector and add a name for your cells Identifier:
Then you need to make your identifier match with your dequeue like this:
let cell2 = tableView.dequeueReusableCellWithIdentifier("ButtonCell", forIndexPath: indexPath) as! ButtonCell
Alternatively
If you're working with a nib you may need to register your class in your cellForRowAtIndexPath:
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "SwitchCell")
// included for context
let cell = tableView.dequeueReusableCellWithIdentifier("SwitchCell", forIndexPath:indexPath) as! SwitchCell
//... continue
}
Apples's UITableView Class Reference says:
Prior to dequeueing any cells, call this method or the
registerNib:forCellReuseIdentifier: method to tell the table view how
to create new cells. If a cell of the specified type is not currently
in a reuse queue, the table view uses the provided information to
create a new cell object automatically.
If you previously registered a class or nib file with the same reuse
identifier, the class you specify in the cellClass parameter replaces
the old entry. You may specify nil for cellClass if you want to
unregister the class from the specified reuse identifier.
Here's the code from Apples Swift 2.0 framework:
// Beginning in iOS 6, clients can register a nib or class for each cell.
// If all reuse identifiers are registered, use the newer -dequeueReusableCellWithIdentifier:forIndexPath: to guarantee that a cell instance is returned.
// Instances returned from the new dequeue method will also be properly sized when they are returned.
#available(iOS 5.0, *)
func registerNib(nib: UINib?, forCellReuseIdentifier identifier: String)
#available(iOS 6.0, *)
func registerClass(cellClass: AnyClass?, forCellReuseIdentifier identifier: String)
In your storyboard you should set the 'Identifier' of your prototype cell to be the same as your CellReuseIdentifier "Cell". Then you won't get that message or need to call that registerClass: function.
If you are going with Custom Static Cells just comment this method:
//- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
// static NSString *CellIdentifier = #"notificationCell";
// UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
// return cell;
//}
and give the cells an identifier at "Attributes Inspector" in storyboard.
I give you the answer in both Objective C and Swift.Before that I want to say
If we use the dequeueReusableCellWithIdentifier:forIndexPath:,we must register a class or nib file using the registerNib:forCellReuseIdentifier: or registerClass:forCellReuseIdentifier: method before calling this method as
Apple Documnetation Says
So we add registerNib:forCellReuseIdentifier: or registerClass:forCellReuseIdentifier:
Once we registered a class for the specified identifier and a new cell must be created, this method initializes the cell by calling its initWithStyle:reuseIdentifier: method. For nib-based cells, this method loads the cell object from the provided nib file. If an existing cell was available for reuse, this method calls the cell’s prepareForReuse method instead.
in viewDidLoad method we should register the cell
Objective C
OPTION 1:
[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:#"cell"];
OPTION 2:
[self.tableView registerNib:[UINib nibWithNibName:#"CustomCell" bundle:nil] forCellReuseIdentifier:#"cell"];
in above code nibWithNibName:#"CustomCell" give your nib name instead of my nib name CustomCell
SWIFT
OPTION 1:
tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "cell")
OPTION 2:
tableView.registerNib(UINib(nibName: "NameInput", bundle: nil), forCellReuseIdentifier: "Cell")
in above code nibName:"NameInput" give your nib name
Working with Swift 3.0:
override func viewDidLoad() {
super.viewDidLoad()
self.myList.register(UINib(nibName: "MyTableViewCell", bundle: nil), forCellReuseIdentifier: "Cell")
}
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = myList.dequeueReusableCell(withIdentifier: "Cell", for: indexPath as IndexPath) as! MyTableViewCell
return cell
}
I spent hours last night working out why my programmatically generated table crashed on [myTable setDataSource:self]; It was OK commenting out and popping up an empty table, but crashed every time I tried to reach the datasource;
I had the delegation set up in the h file: #interface myViewController : UIViewController
I had the data source code in my implementation and still BOOM!, crash every time! THANK YOU to "xxd" (nr 9): adding that line of code solved it for me! In fact I am launching a table from a IBAction button, so here is my full code:
- (IBAction)tapButton:(id)sender {
UIViewController* popoverContent = [[UIViewController alloc]init];
UIView* popoverView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 300)];
popoverView.backgroundColor = [UIColor greenColor];
popoverContent.view = popoverView;
//Add the table
UITableView *table = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, 200, 300) style:UITableViewStylePlain];
// NEXT THE LINE THAT SAVED MY SANITY Without it the program built OK, but crashed when tapping the button!
[table registerClass:[UITableViewCell class] forCellReuseIdentifier:#"Cell"];
table.delegate=self;
[table setDataSource:self];
[popoverView addSubview:table];
popoverContent.contentSizeForViewInPopover =
CGSizeMake(200, 300);
//create a popover controller
popoverController3 = [[UIPopoverController alloc]
initWithContentViewController:popoverContent];
CGRect popRect = CGRectMake(self.tapButton.frame.origin.x,
self.tapButton.frame.origin.y,
self.tapButton.frame.size.width,
self.tapButton.frame.size.height);
[popoverController3 presentPopoverFromRect:popRect inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
}
#Table view data source in same m file
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
NSLog(#"Sections in table");
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSLog(#"Rows in table");
// Return the number of rows in the section.
return myArray.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
NSString *myValue;
//This is just some test array I created:
myValue=[myArray objectAtIndex:indexPath.row];
cell.textLabel.text=myValue;
UIFont *myFont = [ UIFont fontWithName: #"Arial" size: 12.0 ];
cell.textLabel.font = myFont;
return cell;
}
By the way: the button must be linked up with as an IBAction and as a IBOutlet if you want to anchor the popover to it.
UIPopoverController *popoverController3 is declared in the H file directly after #interface between {}
FWIW, I got this same error when I forgot to set the cell identifier in the storyboard. If this is your issue then in the storyboard click the table view cell and set the cell identifier in the attributes editor. Make sure the cell identifier you set here is the same as
static NSString *CellIdentifier = #"YourCellIdenifier";
I had the same issue, was having the same error and for me it worked like this:
[self.tableView registerNib:[UINib nibWithNibName:CELL_NIB_HERE bundle: nil] forCellReuseIdentifier:CELL_IDENTIFIER_HERE];
Maybe it will be usefull for someone else.
I setup everything correctly in the Storyboard and did a clean build but kept getting the error " must register a nib or a class for the identifier or connect a prototype cell in a storyboard"
[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:#"Cell"];
Corrected the error but i'm still at a loss. I'm not using a 'custom cell', just a view with a tableview embeded. I have declared the viewcontroller as delegate and datasource and made sure the cell identifier matches in file. whats going on here?
This might seem stupid to some people but it got me. I was getting this error and the problem for me was that I was trying to use static cells but then dynamically add more stuff. If you are calling this method your cells need to be dynamic prototypes. Select the cell in storyboard and under the Attributes inspector, the very first thing says 'Content' and you should select dynamic prototypes not static.
Just a supplement of the answers:
There may be a time you set all things right, but you may accidentally add some other UIs in you .xib, like a UIButton:
Just delete the extra UI, it works.
Make sure that the CellIdentifier == identifier of the cell in a storyboard, both names are same. Hope this works for u
In my case, the crash happened when I calleddeselectRowAtIndexPath:
The line was [tableView deselectRowAtIndexPath:indexPath animated:YES];
Changing it to [self.tableView deselectRowAtIndexPath:indexPath animated:YES]; FIXED MY PROBLEM!
Hope this helps anyone
In Swift this problem can be solved by adding the following code in your
viewDidLoad
method.
tableView.registerClass(UITableViewCell.classForKeyedArchiver(), forCellReuseIdentifier: "your_reuse_identifier")
you have to be aware that when using interface builder and creating a Xib (nib) containing one cell that there is also a placeholder created that points to the class that will be used. Meaning, when you place two UITableViewCell in one Xib file you possibly run into the exact same trouble causing an *** Assertion failure .... The placeholder mechanism doesn't work adn will be confused then. Instead placing different placeholders in one Xib read on..
The most easy solution (even if that seems a bit to simple) is to place one Cell at a time in one Xib. IB will create a placeholder for you and all works as expected then. But this then leads directly to one extra line of code, because then you need to load the correct nib/xib asking for the reuseIdentified Cell where it resides in.
So the following example code focuses the use of multiple Cell Indentifiers in one tableview where an Assertion Failure is very common.
// possibly above class implementation
static NSString *firstCellIdentifier = #"firstCellIdentifier";
static NSString *secondCellIdentifier = #"secondCellIdentifier";
// possibly in -(instancetype)init
UINib *firstNib = [UINib nibWithNibName:#"FirstCell" bundle:nil];
[self.tableView registerNib:firstNib forCellReuseIdentifier:firstCellIdentifier];
UINib *secondNib = [UINib nibWithNibName:#"SecondCell" bundle:nil];
[self.tableView registerNib:secondNib forCellReuseIdentifier:secondCellIdentifier];
Another trouble with the use of two CellIdentifier's in one UITableView is that row height and/or section height have to be taken care of. Two cells can have different heights of course.
When registering classes for reuse the code should look different.
The "simple solution" looks also much different when your cells reside inside a Storyboard instead of Xib's. Watch out for the placeholders.
Keep also in mind that interface builder files have version wise variations and need to be set to a version that your targeted OS version supports. Even if you may be lucky that the particular feature you placed in your Xib is not changed since the last IB version and does not throw errors yet. So a Xib made with IB set to be compatible to iOS 13+ but used in a target that is compiled on an earlier version iOS 12.4 will cause also trouble and can end up with Assertion failure.
Ran into this error bc cell re-use identifier was wrong-- a rookie mistake but it happens:
1. Makes SURE cell re-use idenifier has no misspellings or missing letters.
2. Along same line, don't forget capitalization counts.
3. Zeroes are not "O"s (Ohs)
I'd like to create custom UITableViewCell using an XIB, but I'm not sure how to recycle it using UITableViewController's queueing mechanism. How can I accomplish this?
Folks, this question was intended to be self answered as per the FAQ, although I love the awesome responses. Have some upvotes, treat yourself to a beer. I asked this because a friend asked me and I wanted to put it up on StackOverflow. If you have anything to contribute, by all means!
If you're using iOS 5 you can use
[self.tableView registerNib:[UINib nibWithNibName:#"nibname"
bundle:nil]
forCellReuseIdentifier:#"cellIdentifier"];
Then whenever you call:
cell = [tableView dequeueReusableCellWithIdentifier:#"cellIdentifier"];
the tableview will either load the nib and give you a cell, or dequeue a cell for you!
The nib need only be a nib with a single tableviewcell defined inside of it!
Create an empty nib and add the table cell as the first item. In the inspector, you can add the reuseIdentifier string in Interface Builder.
To use the cell in your code, do this:
- (UITableViewCell *)tableView:(UITableView *)_tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *reuseIdentifier = #"blah"; //should match what you've set in Interface Builder
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifier];
if (cell == nil)
{
cell = [[[NSBundle mainBundle] loadNibNamed:#"YourTableCellNib" owner:nil options:nil] objectAtIndex:0];
}
//set up cell
return cell;
}
There is another method where you create an outlet for your cell and load the cell nib using the controller as the file's owner, but honestly this is much easier.
If you want to be able to access the subviews you've added to the cell in the nib, give them unique tags and access them with [cell viewWithTag:x];
If you want to be able to set custom properties on the cell, you'll need to create a custom UITableViewCell subclass, then just set that as the class of your nib in InterfaceBuilder and cast the UITableViewCell to your custom subclass when you dequeue it in the code above.
To set up a custom UITableViewCell using a XIB, you have to do several things:
Set up an IBOutlet in your header
Configure the table view cell in Interface Builder
Load the XIB inside of tableView:cellForRowAtIndexPath:
Configure it like any other cell
So... Let's set up an IBOutlet in the header file.
#property (nonatomic, retain) IBOutlet UITableViewCell *dvarTorahCell;
Don't forget to synthesize it inside the implementation file.
#synthesize dvarTorahCell;
Now, let's create and configure the cell. You want to pay attention to the Cell Identifier and the IBOutlet as shown below:
Now in code, you load up the XIB into your cell as shown here:
Notice that the Cell Identifier in Interface Builder matches the one shown in the code below.
Then you go ahead and configure your cell like any other.
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil) {
[[NSBundle mainBundle] loadNibNamed:#"YUOnlineCell" owner:self options:nil];
cell = dvarTorahCell;
dvarTorahCell = nil;
}
//configure your cell here.
Just note that when accessing subviews, such as labels, you now need to refer to them by tag, instead of by property names, such as textLabel and detailTextLabel.
Here how you can do:
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
YourCustomeCell *cell = (YourCustomeCell *)[tableView dequeueReusableCellWithIdentifier:CellClassName];
if (!cell)
{
NSArray *topLevelItems = [cellLoader instantiateWithOwner:self options:nil];
cell = [topLevelItems objectAtIndex:0];
}
return cell;
}
Where cellLoader in .h is defined as follow:
UINib *cellLoader;
and in .m is istantiated as follows (for example during initialization):
cellLoader = [[UINib nibWithNibName:CellClassName bundle:[NSBundle mainBundle]] retain];
and CellClassName is the defined in .m as follows (is also the name for your xib).
static NSString *CellClassName = #"YourCustomeCell";
Do not forget to use the string CellClassName also in your xib created cell.
For further info I suggest you to read this fantastic tutorial creating-a-custom-uitableviewcell-in-ios-4.
Hope it helps.
P.S. I suggest you to use UINib because is an optimized method to load xib files.