I have a simple cell - designed in IB - and with the reuseIdentifier set. Below code works quite nicely. HOWever - the NSLog() reveals that the results are never cached.
Table view controller class:
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
switch/case for various cell types
{
Foo * item = [results objectAtIndex:indexPath.row];
return [MyCell tableView:tableView populatedCellWith:item];
}
}
MyCell class..
+(UITableViewCell *)tableView:(UITableView *)tableView populatedCellWith:(Foo *)item
{
static NSString * identifier = #"XXX";
MyCell *cell = (MyCell *) [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell == nil) {
NSArray * items = [[NSBundle mainBundle] loadNibNamed:#"MyCell"
owner:self options:nil];
cell = [items objectAtIndex:0];
assert( cell && [cell.reuseIdentifier isEqualToString:identifier]);
NSLog(#"That was a load - rather than a nice cache for %#", self.class);
}
fill out some stuff.
return cell;
}
Why is this - as it makes things a lot more efficient ?
Thanks,
Dw.
The way you create the table view cell can not make sure to put the cell into the reusable queue in table view. Only way to do that is to use
initWithStyle:reuseIdentifier:
Initializes a table cell with a style and a reuse identifier and returns it to the caller.
My another question
Are you sure the cells have been set with a cell identifier? UITableView will not cache those without.
Related
I was wondering if anyone knows how to solve this problem:
I have a UITableview, where the datasource can continue to grow. The issue is when I add elements to the data source, the table cells get messed up.
Each table cell has a text field where the user can enter data into it, but whenever I add data to the datasource the comments replicate to other cells.
- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *cellIdentifier = #"ImageTableCell";
ImageTableCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
Picture *aPicture = (Picture *) [self.imageData objectAtIndex:[indexPath row]];
if (cell == nil)
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"ImageTableCell" owner:self options:NULL];
cell = (ImageTableCell *)[nib objectAtIndex:0];
}
NSLog(#"comment %# index %d", aPicture.comment, [indexPath row]);
cell.cellImage.image = aPicture.picture;
cell.commentField.delegate = self;
cell.commentField.text = aPicture.comment;
cell.index = [indexPath row];
cell.tag = [indexPath row];
return cell;
}
self.imagedata is a NSMutabaleArray.
EDIT
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [self.imageData count];
}
-(void) reloadImages:(NSNotification *) aNotification {
self.imageData = ((AppDelegate *)[[UIApplication sharedApplication] delegate]).currentUserData.images;
[self.imageTableView reloadData];
}
a screenshot http://www.mikerizzello.com/pic.png
Thanks
EDIT:
I think you might have a bad MVC pattern. Here's what I would do:
Take your custom cell, ImageViewCell, and make that class your textField delegate. Add a property for your custom Picture object, and set that in cellForRow...
Then, in your textFieldDelegate methods inside the custom cell class, you can change set the contents of your PictureObject there. I have a feeling that you're handling text input in the viewController, and the index of the data object in your array is getting mixed up and you're applying the comment field text to the wrong item in the array.
EDIT
I think it has something to do with cell reuse. The contents of your cell are not getting wiped out upon reusing a cell.
Try this block before you return the cell:
if (!aPicture.comment) {
cell.commentField.text = #"";
} else {
cell.commentField.text = aPicture.comment;
}
Have you try with
if (cell == nil) {
cell = (ImageTableCell*)[[ImageTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
Anyway you can also set different reuseIdentifier for each of cells but it will be bad idea, I would like to help you but i think need to run this project.
Please let me know if code above give better solution.
I am getting too many Object sent - autorelease too many times, this memory leak for my iPhone app and dont know how to resolve it
http://screencast.com/t/fPzMNewvq
Above is screen shot for the same.
SAAdvertiseCell has lot of objects which are releasing, so how is it possible to find where the exact problem is?
Thanks
At first why don't you reuse cells?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
Cell* cell = [tableView dequeueReusableCellWithIdentifier:cell_id];
if(!cell)
{
cell = // create new cell;
}
// configure cell
return cell;
}
And for your problem: seems that initWithData: already returns an autoreleased object, then you send another autorelease. So check that method to find the problem.
For creation of Custom UITableViewCell, write your code in this manner:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"MyTableViewCellId";
MyTableViewCell *cell = (MyTableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:#"MyTableViewCell" owner:self options:nil];
cell = [topLevelObjects objectAtIndex:0];
}
// write your code to customize cell or providing data content
return cell;
}
Hope this will help you to solve your problem
I have configured a table view cell, whose tables cell is loaded from another xib, both the filename and the identities are called,BlogViewControllerTableCell
Most of them works properly, but some contents in the cells keep changing while scrolling.
No matter I use the array value, or simply put the [indexpath row].
The below is the code,
I would be appreciate for your help.
Thanks.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"BlogViewControllerTableCell"];
if (cell == nil) {
// Load the top-level objects from the custom cell XIB.
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:#"BlogViewControllerTableCell" owner:self options:nil];
// Grab a pointer to the first object (presumably the custom cell, as that's all the XIB should contain).
cell = [topLevelObjects objectAtIndex:0];
}
student_name.text = [NSString stringWithFormat:#"%#", [[student_list objectAtIndex:[indexPath row]] objectForKey:#"name"]];
return cell;
}
I am having trouble getting my CustomTableViewCell, a subclass of UITableViewCell to appear in my table view.
I am using a xib to represent that cell, but I am assuming that the code for the data source delegate doesn't change. I made sure to set an identical reuse identifier inside the table view cell XIB.
I isolated the problem to the fact that the datasource method that returns the table cell isn't working correctly, here it is:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
CustomTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
DataObject *foo = [self.dataArray objectAtIndex:indexPath.row];
if (cell == nil)
{
cell = [[CustomTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
[[cell overview] setText:foo.overview];
[[cell price] setText:foo.price];
NSLog(#"cell initialized, description text is %#",cell.overview.text);
return cell;
}
Not sure why this isn't working, but that last log statement always prints a (null) at the end, and yes I did verify that the overview property of the data object has a valid string in it. Same thing for price.
1) Make your Custom cell class separate
2) XIB : File Owner class change to NSObject
3) XIB : UITableViewCell change to MyTableViewCell
4) Where you want to add inside table view code as
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"MyCell";
MyTableViewCell *cell = (MyTableViewCell*) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
NSArray *arrayCellXib = [[NSBundle mainBundle] loadNibNamed:#"MyTableViewCell"
owner:self
options:nil];
if (indexPath.row == 0) {
// first table cell
cell = [arrayCellXib objectAtIndex:0]; // *
......
}else {
cell = [arrayCellXib objectAtIndex:1]; // *
}
...
}
return cell;
}
Object at index 0,1 ... are index for which order you make MyTableViewCell in xib, if you want to have more than one custom cell. means in a MyTableViewCell class u make unlimited custom cell and use according to requirement.
Normally, just make ONE custom cell in the XIB and do exactly this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
int thisRow = indexPath.row;
NSString *exampleText = [yourData objectAtIndex:thisRow];
static NSString *CellID = #"cu5";
FancyCell *cell =
(FancyCell *)[tableView dequeueReusableCellWithIdentifier:CellID];
if (cell == nil)
{
NSArray *cellTeam =
[[NSBundle mainBundle] loadNibNamed:#"FancyCell"
owner:self options:nil];
cell = [cellTeam objectAtIndex:0];
}
[cell someFunction:exampleText];
[cell.someLabel setText:exampleText];
return cell;
}
Hoping may help u :)
In .h file, you write it.
IBOulet CustomTableViewCell *tableCell;
and connect to File's Owner in CustomTableViewCell's .xib file.
You modify this in (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
if (cell == nil)
{
[[NSBundle mainBundle] loadNibNamed:#"CustomTableViewCell" owner:self options:nil];
cell = tableCell;
}
I think it will be helpful to you.
I feel like a real noob asking this, but here's my problem:
I want to show a tableView, with 7 custom cells. None of these cells is reused. That means the user will see 7 different cells, not more, not less.
I created the cells in the viewDidLoad method, and added all those cells in the listCells-array. After that, I used easy-mode to draw those cells:
UITableViewCell *cell = nil;
if (indexPath.row == 0)
{
static NSString *MyIdentifier = #"Cell";
cell = (DetAlertCell *)[localTableView dequeueReusableCellWithIdentifier:nil];
if (cell == nil) {
[[NSBundle mainBundle] loadNibNamed:#"DetAlertCell" owner:self options:nil];
cell = [listCells objectAtIndex:indexPath.row];
}
}
....
However, this won't work. It shows me a blank view. Every cell is created using a .xib-file and a .h and .m class. Is there anything that I'm missing and should do?
Just don't call the [localTableView dequeueReusableCellWithIdentifier:nil] and loa the correct cell for the index path.
Also you say that you load the cells in the viewDidLoad, then why do you load the nib:
[[NSBundle mainBundle] loadNibNamed:#"DetAlertCell" owner:self options:nil];
They should already be the array should they not.
And why to you check if the row is 0 then load the row, still will only load the first row.
Try this:
- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
return [listCells objectAtIndex:indexPath.row];
}