I am working on a project where I need to populate the cells in a table and have them show on the screen. I've got the table to show but now data is being shown in the cells. I've tried using breakpoints and found that this method never gets called. The method just before it (numberOfRowsInSection) does get called. Any suggestions?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
Resident *aResident = (Resident *)[appDelegate.residents objectAtIndex:indexPath.row];
cell.textLabel.text = aResident.name;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
return cell;
}
Have you set the delegate and datasource for the TableView ?
Yeah, numberOfRowsInSection probably returns 0. Show it and where you populate your data source.
Related
I'm trying to use "reloadData" method on a uitableView, it seems like it works (both dataSource method are being called) and when I debug "cellForRowAtIndexPath" the cell that it returns is the correct cell) but I can't see the cell (numberOfRowsInSection is changing and adding blank space for each new cell - So it's not seems to be a threads problem). For example, if I have in the tableView 5 "names" (my data array called "namesArray") and I add 2 there will be 5 names and 2 nil cells presented on the tableView. The problem seems to be with cellForRowAtIndexPath.
cellForRowAtIndex:
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
//Creating "cellIdentifier"(NSString) with "Cell" as the value
NSString *cellIdentifier=#"Cell";
[tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:cellIdentifier];
//Creating a default cell using "cellIdentifier"(NSString)
UITableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath];
if (cell==nil) {
cell=[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
cell.textLabel.text=[namesArray objectAtIndex:indexPath.row];
//Returning cell
return cell;
}
numberOfRowsInSection:
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return self.namesArray.count;
}
-(void)addNameToNamesArray:(NSString*)name
{
[self.namesArray addObject:name];
NSLog(#"namesArray lastObject: %#",[self.namesArray lastObject]);
//NSLog print: The correct name (the one that was added)
[self.tableView reloadData];
}
screenshot for "5 names and 2 nil cells":
Do you have any idea what can it be?
You call
[tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:cellIdentifier];
inside cellForRowAtIndexPath!
Don't you think that's a bit late? And if it worked, you would be calling it a bit often?
And if dequeue... returns nil when a class is registered, something is badly wrong.
change to
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
//Creating "cellIdentifier"(NSString) with "Cell" as the value
static NSString *cellIdentifier=#"Cell";
//[tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:cellIdentifier];
//Creating a default cell using "cellIdentifier"(NSString)
UITableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell==nil) {
cell=[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
cell.textLabel.text=[namesArray objectAtIndex:indexPath.row];
//Returning cell
return cell;
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return self.namesArray.count;
}
set the outlet of tableview and then in addNameToNamesArray method after adding elements reload the tableview
This is likely because you have updated the data in your array, but the table view hasn't accessed that data yet, leading to the nil cells that you see. Since your cells load properly with the initial 5 element in your array, it's probable that you simply haven't refreshed the table view's data. Try using [tableView reloadData] after you have added the new elements to your array.
EDIT 1
What about changing your cellForRowAtIndexPath code to this:
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
//Creating "cellIdentifier"(NSString) with "Cell" as the value
NSString *cellIdentifier=#"Cell";
//Creating a default cell using "cellIdentifier"(NSString)
UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
cell.textLabel.text = [self.namesArray objectAtIndex:indexPath.row];
NSLog(#"name: %#", cell.textLabel.text);
//Returning cell
return cell;
}
Let us know the output of NSLog.
1.Make sure you have initialized self.namesArray in viewDidLoad
Try the following:
[tableView registerClass:[UITableViewCell class]forCellReuseIdentifier:cellIdentifier];
like below:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *cellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
cell.textLabel.text = [namesArray objectAtIndex:indexPath.row];
return cell;
}
Your code is perfectly alright. There can be some possibilities that its not working for you.
You are not initialising your datasource i.e NSMutableArray in your case.
It depends how you are calling addNameToNamesArray method.
If you can share your whole code for that class as how you are calling method and every delegates you are using.
I am trying to make a custom tableview cell for an iPad app, using the Parse framework. When i query without the custom cell, it works fine, but as soon as i am changing the cell identifier, i am just stuck at the loading icon.
The code goes as follows:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath object:(PFObject *)object {
static NSString *CellIdentifier = #"specielCelle";
sagerCelle *cell = (sagerCelle *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
if (cell == nil) {
cell = [[sagerCelle alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
// Configure the cell
cell.lblPolice.text = [object objectForKey:#"police"];
//cell.textLabel.text = [object objectForKey:self.textKey];
//cell.imageView.file = [object objectForKey:self.imageKey];
return cell;
}
Here my advices,(By the way the question is not clear)
Firstly change your identifier with an indexpath.Row
NSString *cellIdentifier=[NSString stringWithFormat:#"CELL_%d",(int)indexPath.row];
Second
if you are changing your existing cell then you are not be able to go inside of the block of
if(cell==nil)
because your cell is not nil. Write else condition.
Hope it helps.
I'm unable to display any accessories in my UITableView cells:
- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
cell.textLabel.text = #"Foo";
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
return cell;
}
Changing the cell styles shows no difference. What's going on here?
Deleting and then creating a new file fixed the problem.
This was a result of having started with an xib file, and then deleted it in favor of doing the whole thing programmatically. Somehow, after deleting the xib, some of the delegation settings stuck.
I'm having an issue in trying to display info in a cell, one on the left and one on the right. I'm aware using initWithStyle with UITableViewCellStyleSubtitle. I use this but it doesn't seem to work.
Here is some sample code:
- (UITableViewCell *)tableView:(UITableView *)ltableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Account Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:Cellidentifier];
}
Accounts *account = [self.fetchedResultsController objectAtIndexPath];
cell.textLabel.text = account.name;
cell.detailTextLabel.text = #"Price";
return cell;
}
I can display cell.textLabel.text just fine, however I cannot get the simple "Price" to be displayed. I've tried different things, such as setting the font size of cell.detailTextLabel.
I've also tried UITableViewCellStyleValue1 as some had suggested in older posts.
Threw NSLog after setting to "Price", shows cell.detailTextLabel as null.
Not sure what I'm doing wrong.
Edit: I found this: cell.detailTextLabel.text is NULL
If I remove if (cell == nil) it works...
That check should be in place, so how do you make it work when using the different styles?
When using storyboards and prototype cells, a cell is always returned from the dequeue method (assuming a prototype with that identifier exists). This means you never get into the (cell == nil) block.
In your case the prototype cell is not defined in the storyboard with the subtitle style, so a subtitled cell is never used, and the detail text label does not exist. Change the prototype in the storyboard to have the subtitle style.
Remove all your code just once you try these lines only and check this will work or not.
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:CellIdentifier]
autorelease];
}
cell.textLabel.text=[Array objectAtIndex:indexPath.row];
cell.detailTextLabel.text=#"Price";
return cell;
}
I see the problem: in your method name, the UITableView variable is named ltableView, not tableView. Change it to tableView.
cell.detailTextLable.text should be cell.detailTextLabel.text. It looks like a simple mis-spelling of label.
All the answers mentioned here are really a workaround i.e. using storyboard.
Here is a way to do it only in code.
Basically instead of registering the identifier for the cell in viewDidLoad do it only once in cellForRowAtIndexPath: method. Also reset cell registered in viewDidLoad __sCellRegistered = 0;
static int _sCellRegistered = 0;
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = nil;
if (__sCellRegistered == 0) {
__sCellRegistered = 1;
NSLog(#"register cell");
cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:#"CellIdentifier"];
[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:#"CellIdentifier"];
};
if (!cell) {
NSLog(#"dequeue");
cell = [tableView dequeueReusableCellWithIdentifier:#"CellIdentifier" forIndexPath:indexPath];
}
myaI have this code:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
if (tableView == firstTableView){
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell == nil){
cell = [[[UITableViewCell alloc]initWithStyle:UITableViewStylePlain reuseIdentifier:CellIdentifier] autorelease] ;
}
cell.textLabel.text = [myArray objectAtIndex:indexPath.row];
return cell;
}
}
I check if tableview is firsttableview, but it give me a warning because the method haven't a "return" cell, how can I solve?
You only return a cell if the table is firstTableView. Make sure you return a cell for other tables by adding a return statement outside of your conditional.
Your code needs to return a value for all paths through that method. So, if your check for firstTableView fails, you still need to return a valid UITableViewCell from the method. You should probably read the UITableView programming guide - it walks you through proper usage of a tableview.