just created an UITableView,
trying to display some custom data from an array, but what ever I do, i get no text displayed.
NSLog tell me the right text and right amout but no text in table cell.
here is the code:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier];
}
cell.textLabel.text = #"test";
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
Things to check:
Is cellForRowAtIndexPath getting called? Put a breakpoint in
Make an array in ViewDidLoad (property, alloc'd) and addObjects #"One", #"Two", #"Three", nil and then cell.textLabel.text = [theArray objectAtIndex:indexPath.row];
IfcellForRow is being called, this will show in the cells.
What doesConfigureCell do? Include the code please.
Also check your tableView delegate methods are being called (NumberofRowsInSection etc)
Always set cell properties (text, images, accessory views, etc) in the
tableView:willDisplayCell:forRowAtIndexPath
delegate method.
UITableView sometimes send a prepareForReuse to the cell after it is returned from
tableView:cellForRowAtIndexPath
which causes the cell to reset it's labels and images.
Related
I can't seem to get dequeueReusableCellWithIdentifier working.
I need to build a project for IOS 4 so I can't use storyboards, but I'm using ARC.
Let's say I have 2 sections, each with 1 row.
Looking at the code below, I'm using the strong property to pass ownership, since ARC would insert the "autorelease" code.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = #"TableCellIdentifier";
MainTableCell *cell = (MainTableCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil)
{
self.retainedCell = [[MainTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
However, for each row, cell is always nil (and hence a new MainTableCell is alloc'd) each time the function is called. The cell is never re-used.
This wouldn't be so much a problem except I programmatically call tableView:cellForRowAtIndexPath:, meaning I get a newly alloc'd cell each time, rather than the existing cell.
The only method I can see is to add the cells to an NSMutableArray.
Is there something I'm missing with dequeueReusableCellWithIdentifier now?
Thanks!
EDIT
I'm using the code below to get the cell. As mentioned it's creating a new cell not re-using the one that should have been already made + retained.
I don't need to invoke reloadData for all the rows, just change a specific one.
MainTableCell *cell = (MainTableCell *)[self tableView:self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]];
[self configureCell:cell atIndexPath:indexPath];
You happen to be de-queuing MainTableCell, and then you proceed to check if it is nil, at which point you use a completely different var to alloc a table cell. What the heck? Try this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = #"TableCellIdentifier";
MainTableCell *cell = (MainTableCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil)
{
cell = [[MainTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
I am using ios5 storyboards with a UITableViewController with a UITableViewCell subclass. I do not want to design the visual elements of the cell in the storyboard designer for the view, because I want to use a reusable subclass of UITableViewCell (specifically TDBadgedCell).
I have set my cell identifier in the storyboard designer, and all of the rows load correctly in the UITableView as long as I'm not setting any of the properties unique to TDBadgedCell. If I set the badgeString property though which is unique to TDBadgedCell, I get an exception. I narrowed down that dequeueReusableCellWithIdentifier: is not returning a cell of type TDBadgedCell.
I'm only running into this with a UITableViewController. I have a UIViewController with an embedded UITableView set up in the same fashion and it's not an issue. Any ideas?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath
{
static NSString *CellIdentifier = #"PhoneNumberCell";
TDBadgedCell *cell = (TDBadgedCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[TDBadgedCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
if ([cell isKindOfClass:[TDBadgedCell class]])
{
NSLog(#"It is TDBadgedCell");
}
else
NSLog(#"It is NOT TDBadgedCell");
I had a similar issue in that I am subclassing UITableViewCell but not using storyboard. Here is my solution to using different cell classes dependent on if the user had purchase the unlock feature of the app. Hope it helps someone.
In a nutshell, I had the cell with several objects including a UITextView object. I wanted to lock down the copy and paste feature of the UITextView object in the lite version but then release the feature once the user had purchased in in-app product.
I had two UITableViewCell classes, one with UITextView as it is and another with UITextView subclassed with canBecomeFirstresponder returning NO. That way the user could still scroll up and down the UITextview data but not copy and paste the data.
Here is the code and all I had to do was rename the reuse identifiers.
WHY? Because [self.tableview reloadData] would not rebuild the cells with the new class as the cell was still in existence. New cells off the screen would get the new class but existing ones would not. This solution rebuilds all cells once off after the purchase unlocking the added feature.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if (your test if in-app was purchased is yes)
{
static NSString *MyIdentifier = #"MyCell";
FrontCell *cell = (FrontCell *)[tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil)
{
cell = [[FrontCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MyIdentifier];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.shouldIndentWhileEditing = NO;
}
//....///
cell.trackDetails.text = [yourObject objectAtIndex:indexPath.row];
cell.trackDetails.delegate = self;
cell.trackDetails.tag = indexPath.row;
return cell;
}
else // inapp not purchased
{
static NSString *MyLockedIdentifier = #"MyLockedCell";
FrontCellLocked *cell = (FrontCellLocked *)[tableView dequeueReusableCellWithIdentifier:MyLockedIdentifier];
if (cell == nil)
{
cell = [[FrontCellLocked alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MyLockedIdentifier];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.shouldIndentWhileEditing = NO;
}
//....///
cell.trackDetails.text = [yourObject objectAtIndex:indexPath.row];
cell.trackDetails.delegate = self;
cell.trackDetails.tag = indexPath.row;
return cell; }
}
In storyboard,you can set the Custom Class property for a subclass of UITablviewCell.
Then dequeueReusableCellWithIdentifier method will return cell with the type of your subclass.
I think you are using wrong method for dequeuing the cells.
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [self.tblProfileInfo dequeueReusableCellWithIdentifier:#"PostCell" forIndexPath:indexPath];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
return cell;
}
You forgot for indexPath at the end.
I have a UITableView, and I am showng data based on indexPath.section, however, when I scroll my table view very quickly, its data keep overlapping. How to fix this?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
}
switch(indexPath.section)
{
// case 0 to 10;
//values change if I scroll my table
}
}
I think you are allocating some labels inside the cellForRowAtIndex delegate method. Thats why you got this problem. You can solve this in 2 ways:
Alloc the labels outside the delegate
method. set tags for your labels and
use it inside the cellForRowAtIndex
by refering the tags.
use custom cell view controller.
i fixed the issues
here is the solution if any one need
NSString *CellIdentifier=nil ;
NSMutableArray *Array= [[[NSMutableArray alloc] initWithObjects: #"One",#"Two", #"Three",#"Ad",#"Ae",#"Ah",#"Aj" ,nil]autorelease];
CellIdentifier = [Array objectAtIndex:indexPath.section];
///302-1021-9244-4658-1994-3384
UITableViewCell * cell = [tabelView dequeueReusableCellWithIdentifier:CellIdentifier];
Thanks
i have a tableview that contains a uiwebview in its first row. i would like to change this tables' webview object with new one when user clicks a button. i am using the code given below but it does not work fine. older object is there and the newer one is over it although i recreate the webview. how can i remove the older one from cell?
thanks...
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
NSLog(#"NİL.......");
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
} else {
NSLog(#"NOT NİL.......");
}
[cell addSubview:webView];
return cell;
}
Since you are using "dequeueReusableCellWithIdentifier", your should reconfigure the cell each time when the cell is displayed.
Please remember that the cells with same identity will be reused. It's better to set the same identity to one particular type of cells, typically cells with same subviews and layout.
This is sample for how to load data and reconfigure a cell: http://code.google.com/p/tweetero/source/browse/trunk/Classes/MessageListController.m
Here is a tutorial to get familiar with UITableView:
http://developer.apple.com/library/ios/#documentation/userexperience/conceptual/TableView_iPhone/CreateConfigureTableView/CreateConfigureTableView.html
I just have a basic (noob) question about cellForRowAtIndexPath get called?
I'm working through example code and I don't see it explicitly called anywhere?
Does any component of type UITableViewComponent automatically call this function when it is created?
Thanks
When a UITableView is displaying this method gets called per row. In it you will customize each cell with particular data for display.
Here's the class reference.
Here's a sample:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"FriendCellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
NSUInteger row = [indexPath row];
cell.accessoryType = UITableViewCellAccessoryDetailDisclosureButton;
Item *i = [itemArray objectAtIndex:row];
cell.textLabel.text = [i name];
cell.detailTextLabel.text = [i brewery];
[i release];
return cell;
}
This is called for each cell when the corresponding UITableView gets drawn. An index path is passed in, and based on the section and cell numbers, your code should generate a UITableViewCell to be displayed in the UI.
You can look here for a quick tutorial into how UITableViews work.