UITableView indexPath null issue - objective-c

I have this issue with my UITableView. When i drag the table so that the bottom row is half way up, i get a crash. When I basically drag the bottom row all the way as up as i can get it. The code snippet is below:
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [table dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
NSString *section = [[browseCategoriesDictionary allKeys] objectAtIndex:indexPath.section];
NSArray *objectsForSection = [browseCategoriesDictionary objectForKey:section];
NSString *cellValue = [objectsForSection objectAtIndex:indexPath.row];
cell.textLabel.text = cellValue;
cell.backgroundColor = [UIColor colorWithRed:0x7C/255.0 green:0x7E/255.0 blue:0xBB/255.0 alpha:1];
cell.detailTextLabel.numberOfLines = 3;
cell.detailTextLabel.textColor = [UIColor whiteColor];
cell.detailTextLabel.text = [cellDescriptions objectAtIndex:indexPath.row];
cell.imageView.image = [UIImage imageNamed:[cellIcons objectAtIndex:indexPath.row]];
return cell;
}
Thanks guys

Please check the different data sources that you are using are not returning nil values, it may result in a crash.

Related

UILabel showing wrong Values in UITableView

I am using Coredata and NSFetchedResultsController to store and retrieve Values and show them in a table view.I am creating a custom label in cellForRowAtIndexPath and displaying the value of an attribute 'lastname'. But I am getting wrong values.
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
UILabel *label = nil;
if(cell == nil){
cell = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier]autorelease];
label = [[[UILabel alloc]initWithFrame:CGRectMake(160,10,120,21)]autorelease];
label.backgroundColor = [UIColor clearColor];
[cell.contentView addSubview:label];
//Configure the cell
List *list = [self.fetchedResultsController objectAtIndexPath:indexPath];
label.text = list.lastname;
}
[self configureCell:cell atIndexPath:indexPath];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
cell.selectionStyle = UITableViewCellSelectionStyleGray;
return cell;
}
the wierd part is that it is working fine if i remove the UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; line and the if condition.
You need to move
label.text = list.lastname;
outside of the
if(cell == nil)
The reason is, that the content inside of the if(cell == nil) will get called only x times, where x is the number of visible cells on the screen. As you scroll, the new cells are being reused and that's why they contain some incorrect value.
EDIT:
You will also need to move your
List *list = [self.fetchedResultsController objectAtIndexPath:indexPath];
outside of the if.
EDIT 2:
This is how it should look like:
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
UILabel *label = nil;
if(cell == nil){
cell = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier]autorelease];
label = [[[UILabel alloc]initWithFrame:CGRectMake(160,10,120,21)]autorelease];
label.backgroundColor = [UIColor clearColor];
label.tag=1;
[cell.contentView addSubview:label];
}
[self configureCell:cell atIndexPath:indexPath];
//Configure the cell
List *list = [self.fetchedResultsController objectAtIndexPath:indexPath];
label = (UILabel*)[cell.contentView viewWithTag:1];
label.text = list.lastname;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
cell.selectionStyle = UITableViewCellSelectionStyleGray;
return cell;
}
this should work for you

How to make SDWebImage maintain size in UITableViewCell

cell.imageView is displayed correctly on first loading.
After the UITableViewCell move off screen and back on again, suddenly cell.imageView size has changed to fill the height of the cell.
Same thing when the cell set to highlighted state.
cell.imageView is created in interface builder.
(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"CustomCell";
CustomCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[CustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
NSDictionary *dataType = [self.dataTypes objectAtIndex:indexPath.row];
[cell.imageView setImageWithURL:[NSURL URLWithString:[dataType valueForKey:#"imageURL"]]
placeholderImage:nil];
cell.titleLabel.text = [data valueForKey:#"name"];
cell.descriptionLabel.text = [data valueForKey:#"info"];
return cell;
}
try below answer and do needful changes in it
https://stackoverflow.com/a/15331306/1713478
in this answer add
cell.titleLabel.text = [data valueForKey:#"name"];
cell.descriptionLabel.text = [data valueForKey:#"info"];
and just change SimpleTableCell with CustomCell and in imageURL put your image URL
and do other needful changes.
may be your problem will solve.
Well inspired by Pratik's answer I decided to remove the UIImageView from interface builder and create it on the fly. This works as expected but I'm not sure why it's any different. Possibly something to do with the IB constraints.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"CustomCell";
CustomCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[CustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
NSDictionary *data = [self.dataTypes objectAtIndex:indexPath.row];
UIImageView *thumb = [[UIImageView alloc]initWithFrame:CGRectMake(11, 10, 52, 74)];
[thumb setImageWithURL:[NSURL URLWithString:[data valueForKey:#"imageURL"]]
placeholderImage:nil];
[cell addSubview:thumb];
[thumb release];
cell.titleLabel.text = [data valueForKey:#"name"];
cell.descriptionLabel.text = [data valueForKey:#"info"];
return cell;
}

Table cell subtitles not displaying

I setup the cell style to subtile in the inspector but still no subtitles, just blank but the title is displayed
here is the section in the view controller:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath;
{
UITableViewCell *cell = nil;
cell = [tableView dequeueReusableCellWithIdentifier:#"homeworkcell"];
if(cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"homeworkcell"];
}
cell.textLabel.text = [tabledata objectAtIndex:indexPath.row];
cell.detailTextLabel.text = [tablesubtitles objectAtIndex:indexPath.row];
cell.textLabel.font = [UIFont systemFontOfSize:14.0];
//static NSString *CellIdentifier = #"Cell";
/* if (cell == nil) {
cell = [[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:CellIdentifier];
}*/
// Configure the cell.
//-----------------------------------------START----------------------------Set image of cell----
cellImage = [UIImage imageNamed:#"checkboxblank.png"];
cell.imageView.image = cellImage;
//--------------------------------------------END---------------------------end set image of cell--
return cell;
}
You need to use the UITableViewCellStyleSubtitle when you create a new UITableViewCell, not UITableViewCellStyleDefault. UITableViewCellStyleDefault only shows the textLabel in the cell, not the detailTextLabel.
See the "Cell Styles" section of the UITableViewCell reference and the "Standard Styles for Table View Cells" of the Table View Programming Guide.

Changing specific cells in uitableview

I have a uitableview but I want to disable some cells and leave others enabled.
I used the following code to disable all cells except for the first in the cellForRowAtIndexPath:
if ([indexPath row] > 0 ) {
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.userInteractionEnabled = NO;
cell.textLabel.textColor = [UIColor lightGrayColor];
}
But instead of disabling all cells and enabling the first, it disabled all cells and enables the last. Why does this happen? And what can I do to get it to work?
BTW Here's my code for all cellForRowAtIndexPath:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
sectionContents = [[self listOfItems] objectAtIndex:[indexPath section]];
contentsForThisRow = [sectionContents objectAtIndex:[indexPath row]];
if ([indexPath row] > 0 ) {
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.userInteractionEnabled = NO;
cell.textLabel.textColor = [UIColor lightGrayColor];
}
static NSString *CellIdentifier = #"Cell";
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
}
cell.textLabel.text = contentsForThisRow;
return cell;
}
Replace your code of cellForRowAtIndexPath: with this one
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
sectionContents = [[self listOfItems] objectAtIndex:[indexPath section]];
contentsForThisRow = [sectionContents objectAtIndex:[indexPath row]];
static NSString *CellIdentifier = #"Cell";
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
}
cell.textLabel.text = contentsForThisRow;
if ([indexPath row] > 0 ) {
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.userInteractionEnabled = NO;
cell.textLabel.textColor = [UIColor lightGrayColor];
}
return cell;
}
You don't show where you declare cell, but what you are doing is setting the userinteractionEnabled before getting the actual cell!
You have to put this customization code at the end of the method.
Also, try to declare the cell variable in the method, it has not to be used elsewhere.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
sectionContents = [[self listOfItems] objectAtIndex:[indexPath section]];
contentsForThisRow = [sectionContents objectAtIndex:[indexPath row]];
static NSString *CellIdentifier = #"Cell";
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
}
if ([indexPath row] > 0 ) {
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.userInteractionEnabled = NO;
cell.textLabel.textColor = [UIColor lightGrayColor];
}
cell.textLabel.text = contentsForThisRow;
return cell;
}

adding different UILabel to each cell in UITableView

I'm adding different text to each cell in UITableView. However when I do that, test is displayed in every cell except for the first one..So if theres an array with 9 numbers between 1 to 9, 1 is displayed in the second cell, 2 is displayed in the third cell and respectively. There's nothing shown in the first cell fromHeres the codes
// Customize the appearance of table view cells.
- (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] autorelease];
cell = [self getCellContentView:CellIdentifier];
}
if (indexPath.row == 0) {
NSLog(#"hi");
}
//add another textfield
NSString *path = [[NSBundle mainBundle] pathForResource:#"Rankvalue" ofType:#"plist"];
NSMutableArray* rank = [[NSMutableArray alloc] initWithContentsOfFile:path];
NSString *rankValue = [rank objectAtIndex:indexPath.row];
UILabel *rankLabel = (UILabel *)[cell viewWithTag:1];
rankLabel.text = rankValue;
[rankLabel setFont:[UIFont fontWithName:#"austin power" size:[#"40" intValue]]];
CGRect labelFrame = CGRectMake(220,70,50,40.0);
[rankLabel setFrame:labelFrame];
// Configure the cell(thumbnail).
cell.textLabel.text = [self.stars objectAtIndex:indexPath.row];
NSString *path2 = [[NSBundle mainBundle] pathForResource:#"Filename" ofType:#"plist"];
self.filename = [[NSMutableArray alloc] initWithContentsOfFile:path2];
cell.imageView.image = [UIImage imageNamed:[self.filename objectAtIndex:indexPath.row]];
//transparent cell
cell.backgroundColor = [UIColor clearColor];
[rankLabel release];
[rankValue release];
return cell;
}
And this is the code for the subview of the cell
- (UITableViewCell *) getCellContentView:(NSString *)cellIdentifier {
CGRect CellFrame = CGRectMake(0, 0, 320, 65);
CGRect Label1Frame = CGRectMake(17,5,250,18);
UILabel *lblTemp;
UITableViewCell *cell = [[[UITableViewCell alloc] initWithFrame:CellFrame reuseIdentifier:cellIdentifier] autorelease];
lblTemp = [[UILabel alloc] initWithFrame:Label1Frame];
[lblTemp setFont:[UIFont fontWithName:#"Arial-Bold" size:15]];
lblTemp.tag = 1;
lblTemp.backgroundColor=[UIColor clearColor];
lblTemp.numberOfLines=0;
[cell.contentView addSubview:lblTemp];
return cell;
}
initWithFrame:reuseIdentifier: has been deprecated for initWithStyle:reuseIdentifier:
You should create one of the standard styles.
Set the values you want (font, etc.) on cell creation, not on refresh. Frame of text field is the same. And background color.
You really don't want to reload that plist (oh, there's two of them!) every time you refresh a cell! Load it once in another method and cache it as an ivar.
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
// create and set up all the layout attributes of the cell
// it should be auto released
// which should include a call like the following, or loading a cell from a nib
// cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
// reuseIdentifier:CellIdentifier];
// [cell autorelease];
}
// the only thing that should happen here is setting the data values
// into the cell!!!!!! All these values should be loaded once and
// kept as "model state" by the controller. Do not create an image
// each time through, do not load an entire plist to access one item
// each time through
rankLabel.text = rankValue;
cell.textLabel.text = [self.stars objectAtIndex:indexPath.row];
cell.imageView.image = [self imageAtRow:indexPath.row];
}
If the image your displaying is different for each cell, using imageNamed: is not appropriate. If there's 2 or 3 images that indicate type of cell that will each be used a lot, imageNamed: is likely preferable. imageWithContentsOfFile: is your other option, you'll need to build the full path
Try switching this:
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
//cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
cell = [self getCellContentView:CellIdentifier];
}
for this:
UITableViewCell *cell=[self getCellContentView:CellIdentifier];
Not saying it will work, but just give it a shot. Also, do this inside your getCellContentView:
[lblTemp release]
Or you will have a leak.