Error on collectionView dequeueReusableCellWithIdentifier - iphone

I am having trouble in converting a uitable into collectionview.
I have the following code but it has error on "collectionView dequeueReusableCellWithIdentifier"May I know what;s the problem?
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
return 1;
}
// Return the number of rows in the section (the amount of items in our array)
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return [pictureListData count];
}
// Create / reuse a table cell and configure it for display
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
cellForItemAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"Cell";
UICollectionViewController *cell = [collectionView dequeueReusableCellWithIdentifier:CellIdentifier];
// Get the core data object we need to use to populate this table cell
Pictures *currentCell = [pictureListData objectAtIndex:indexPath.row];

You have the wrong method name. For UICollectionViews the method is:
- (id)dequeueReusableCellWithReuseIdentifier:(NSString *)identifier forIndexPath:(NSIndexPath*)indexPath
So you need to change
UICollectionViewController *cell = [collectionView dequeueReusableCellWithIdentifier:CellIdentifier];
to
UICollectionViewController *cell = [collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];

Related

Collectionview doesn't show anything during runtime

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return getName.count;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
static NSString *identifier = #"Cell";
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:identifier forIndexPath:indexPath];
UIImageView *recipeImageView = (UIImageView *)[cell viewWithTag:100];
recipeImageView.image = [UIImage imageNamed:[getName objectAtIndex:indexPath.row]];
return cell;
}
When I run the app then it doesn't show anything.what are the reasons behinds that
Mostly its tag issue cause as per your crash log
[UICollectionViewCell setImage:] means image is directly set to UICollectionViewCell not recipeImageView. so you have to check proper tag value..
so ones check tag value of image view..
otherwise check that you have register your collection view cell.

UITableView Content "Static cell" not working in iOS7

I have a problem in my storyboard.It is working fine but when i try to change the content property of UITableView it caused following error
Assertion failure in -[UITableView dequeueReusableCellWithIdentifier:forIndexPath:], /SourceCache/UIKit/UIKit-2903.23/UITableView.m
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'
I want to design a grouped tableview with static cell.Thanks in advance
Code
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 2;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 3;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
return cell;
}
if you use static cell, just comment all the UITableViewDatasourceDelegate method. so comment the following code:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 2;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 3;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
return cell;
}
Wish this will help you!
Instead of using:
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
//-> This is used when using prototype cells (e.g) Dynamic TableView
Use:
UITableViewCell *cell = [super tableView:tableView
cellForRowAtIndexPath:indexPath];
//-> Since you chose Static TableCells you don't need to reuse instead use the cells you created in nib
I have encountered same issue, and I think I found the way to work this out.
Create a Controller extends from UITableViewController to wrap its controller, it will have default UITableViewDelegate and UITableViewDataSource methods.
Remove UITableView delegate and datasource
Delete default UITableViewDelegate and UITableViewDataSource methods from your controller file, coz it's static cells, so if these exist, will not appear
Hope it helps.
When using storyboard the tableview cell must be registered in the storyboard.That means cell must be added to the table and its identifier must be set.This identifier should be used in the code in cellForRowAtIndexpath
EDIT
In case of static cells the each purticular cells needed to be created in the nib and filled content via code or nib
Read this
Loading Table View Cells from a Storyboard
Excellent starter
You are not allowed to use static cells in a normal UITableView.
Instead you need to use UITableViewController to go with the static cells.
this and this may or might help.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [YourArr count];
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 44;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *CellIdentifier = [NSString stringWithFormat:#"cell %d",indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell = nil;
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
return cell;
}
Add this code in cellForRowAtIndexPath
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil];
}
else
{
UIView *subview;
while ((subview= [[[cell contentView]subviews]lastObject])!=nil)
[subview removeFromSuperview];
}

Error returning cell from tableView

I am relatively new to using table view in ios. I am trying to edit data using different view and update the values from original view. I set cell identifier and wrote following code.
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return self.items.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath: (NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"NameIdentifier";
Item *currentItem=[self.items objectAtIndex:indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
// Configure the cell...
cell.textLabel.text=currentItem.itemName;
return cell;
}
But I get the following error:
NSInternalInconsistencyException',
reason: 'UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:'
You need to check and make sure dequeueReusableCellWithIdentifier was able to dequeue a cell. It's crashing because it doesn't return a cell every time. If you were unable to dequeue a reusable cell you need to create a new one. Your code should look like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath: (NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"NameIdentifier";
Item *currentItem=[self.items objectAtIndex:indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
cell = [[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier];
// Configure the cell...
cell.textLabel.text=currentItem.itemName;
return cell;
}

cellForRowAtIndexPath always return nil

I have created sample application that insert 12 rows in tableview.And inserted fine.When after inserted my rows i dont want any changes in text during scrolling of tableview.So i checked with indexpath row has value of UITableViewCell , if it has values means return that cell otherwise we created new UITableViewCell.
My sample code is below
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
NSLog(#"GlobalCount = %d",GlobalCount);
return GlobalCount;
}
- (UITableViewCell *)tableView:(UITableView *)tv cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *obj = (UITableViewCell*)[tableView cellForRowAtIndexPath:indexPath];
if(obj!=nil)
{
NSLog(#"cell indexpath row = %d",indexPath.row);
NSLog(#"cell text = %d",obj.textLabel.text);
return obj;
}
else {
NSLog(#"obj==nil");
}
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tv dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
if([DataTable count]>0)
cell.textLabel.text = [DataTable objectAtIndex:0];
// Configure the cell.
return cell;
}
What my objective is , i dont want update any text (or UITableViewCell)for already created indexpath rows(of cell).So i can check this in cellForRowAtIndexPath , but it always return nil.If i am missing anything ?
I checked using this line
UITableViewCell *obj = (UITableViewCell*)[tableView cellForRowAtIndexPath:indexPath];
if(obj!=nil)
Plz help me?
Thanks in advance......
Let the table view decide id it need to update the cell or not. Just remove all the firsdt part of your code and everything will run smoothly.
Don't hesitate to read the UITableView doc.

Cell customization in iPhone Application

I want to make a table view in my iPhone Application.. In that table each shall contains 1 image, some text of line, some symbols, etc.. I don't now how to customize our cell of table. Please provide some help if you have..
I think you can use a default UITableViewCell to do what you described by initializing the Cell (in - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath ) with the proper UITableViewCellStyle
e.g.:
-(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];
}
// Set up the cell...
return cell;
}
which gives you:
"A style for a cell with a left-aligned label across the top and a left-aligned label below it in smaller gray text. The iPod application uses cells in this style."
Also every kind of UITableViewCell has an image-property by default.
but here are some tutorials for building custom cells:
Custom UITableViewCells with Interface Builder
http://iphone.zcentric.com/2008/08/05/custom-uitableviewcell/
You can create a cell in Interface Builder. Start with a UITableViewCell which acts like a view, and then add a UIImage, one or more labels, whatever containers to hold your symbols, etc.
Then in your cellForRowAtIndexPath, load the nib and fill in the picture and labels, etc.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
MyTableCell *cell = (MyTableCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = myTableCell; // get the object from the outlet
myTableCell = nil; // make sure this can't be re-used accidentally
}
// Set up the cell...
cell.myViewController = self;
// set up image and labels here
return cell;
}