When i scroll UITableView it crashes the app. Here is code.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSDictionary *tempDict = [albums objectAtIndex:indexPath.row];
static NSString *CellIdentifier = #"ImageCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
} else {
AsyncImageView *oldImage = (AsyncImageView *)[cell.contentView viewWithTag:999];
[oldImage removeFromSuperview];
}
I set the breakpoints and it stops at line
NSDictionary *tempDict = [albums objectAtIndex:indexPath.row];
What am i doing wrong?
Thanks in advance.
I am not sure, first of all please check the total number of rows and your array count. They must be same. If still it crashes then put this line
NSDictionary *tempDict = [[albums objectAtIndex:indexPath.row] copy];
Check size of albums array. May be it is smaller then indexPath.row or it was released somewhere.
Make sure you are not reading out of bounds of your NSdictionary.
Check your return value in the tableView:numberOfRowsInSection: dataSource method.
The most likely reason for a crash on that line is that your table view has more rows than you have items in your albums array. Normally, in a setup like this, you'd have exactly the same number of rows in your table, and your implementation of –tableView:numberOfRowsInSection: would look like this
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// assuming that there is only one section
return [albums count];
}
I solved this problem. Actually in the $cellForRow ,I was trying to get information from server, I did not apply lazy loading there. Because of that while scrolling the tableView, app was crashing.
Thank you to all for your help.
Related
I am trying to make a ToDo list app and I can't for the life of me seem to figure out how to make the text box's typed text go into a box with a tick box for me to be able to change to completed.
Can anyone help me? I am just getting started in Xcode so please explain why/how it works that way I can learn for the future. Thanks guys!
App Rendering (What I am trying to make)
http://imgur.com/wcNXu0z
Currently in Xcode (What I have so far)
http://imgur.com/PLUVaVg
You need to create an IBAction for add button. So its get called when you click the button and store the entered text in UItextfield in an array and you will use that array to add rows in your table.
For example consider the code :
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [dataArray count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *MyIdentifier = #"MyIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:MyIdentifier] autorelease];
}
[cell.textLabel setText: [dataArray objectAtIndex:indexPath.row];
return cell;
}
-(IBAction)addCity:(id)sender
{
[tableView beginUpdates];
[dataArray addObject:#"City"];
NSArray *paths = [NSArray arrayWithObject:[NSIndexPath indexPathForRow:[dataArray count]-1 inSection:1]];
[[self tableView] insertRowsAtIndexPaths:paths withRowAnimation:UITableViewRowAnimationTop];
[tableView endUpdates];
}
I'd strongly recommend you check out the free Sensible TableView framework. The framework should help you automatically create your text fields and automatically fill/save their data.
i am having dynamically created UITableView. I want to add 3 dummy row when the table view have ben populated from array.
My scenario is that when there is sufficient data in the UITableView, then at the bottom of uitable dummy rows with blank text.
In this way even if there is 40 records, by scrolling up the last two rows will be visible.
suppose my array count is 14 (which is dynamic/not always 14) then how do i add three blank row in index path 14,15,16 and setting their text as:
cell.textlabel.text=#"";
You can do like this.
retune no of row like this below.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [array count]+2;
}
After that manage this in cellRowAtindexPath method like shown in below:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
[cell setSelectionStyle:UITableViewCellSelectionStyleNone];
[tableView setPagingEnabled:NO];
//[tableView setSeparatorColor:[UIColor colorWithPatternImage:[UIImage imageNamed:#"longDotedLine.png"]]];
if (indexPath.row < [array count]) {
cell.textLabel.text = #"Test Data";
} else {
cell.textLabel.text = #"";
}
return cell;
}
Try this may be this help you.
Thanks,
MinuMaster.
Add some variable which has count three more than arra count.Like if ur array has 12 elements,The variable say totalRow=[array Count]+3;
Comapare this in cellForRowAtIndexPAth delegate and do your operation
I am surprise why such question arised?? What is problem in detecting the Last Record of Dynamic Data?
If you are taking any number of dynamic data in Array then simply you can Keep RowCount +1 and check if last record is reached in cellForRowAtIndexPath. If yes, then simply add a Your Last statement i.e cell.textLabel.text = #""; for last record.
Did you try something like:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return ([array count] + 3);
}
I know this is going to be one of those head-smacker moments.
I have a UITableView from which I need to delete cells. Problem is, didSelectRowAtIndexPath is only called if I first tap the row and then swipe to show the delete button. If I swipe the row without explicitly tapping the row, then I get an EXC_BAD_ACCESS error. I put an NSLog into didSelectRowAtIndexPath and can see the indexPath array when I tap the cell, but nothing if I just swipe without clicking.
I've done my share of searching and I'm 99% sure my delegate is hooked up correctly (usually problem #1) and didn't type didDeselectRowAtIndexPath (usually problem #2). I also have in my .h file (problem #3).
Thanks in advance.
EDIT:
I should have said: If I swipe the row without explicitly tapping the row, then I get an EXC_BAD_ACCESS error when I tap the Delete button. If I tap the cell and then swipe, I can tap Delete and it deletes as expected.
EDIT:
(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];
}
NSSortDescriptor *aSortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:YES];
[bandList sortUsingDescriptors:[NSArray arrayWithObject:aSortDescriptor]];
NSDictionary *dict = [bandList objectAtIndex:indexPath.row];
cell.textLabel.text = [dict objectForKey:#"name"];
return cell;
}
- (void)tableView: (UITableView *)tableView didSelectRowAtIndexPath: (NSIndexPath *)indexPath
{
NSLog(#"IndexPath: %#", [indexPath description]);
}
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete)
{
NSDictionary *selectedBand = [bandList objectAtIndex:indexPath.row];
NSString *selectedBandId = [selectedBand objectForKey:#"id"];
[self deleteMyBand:selectedBandId];
bandList = [self getSavedBands];
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
}
These lines jump out at me:
NSDictionary *selectedBand = [bandList objectAtIndex:indexPath.row];
NSString *selectedBandId = [selectedBand objectForKey:#"id"];
I don't understand your reasoning for taking a value from an array, sticking it into a dictionary, then getting a string out of that dictionary. Shouldn't the value returned from
[bandList objectAtIndex:indexPath.row];
Be the same as what you get in selectedBandId?
Also, I can't analyze it any further when I don't know what "deleteMyBand" and "getSavedBands" do. Try commenting out those calls and seeing if the visible row itself can be deleted. That may tell you where the problem is.
Not exactly sure why, but the fact that I was using a sorted NSMutableArray for my source data seems to have been the problem. When I was deleting the row from the table and updating the MutableArray, I got the crash. However, if I created my source data as an NSArray, made a mutableCopy of the array into a temporary MutableArray, removed the row, resorted the array, and then wrote the MutableArray back out to an NSArray, everything is peachy.
I don't think this explanation makes sense, but it's the pattern I'm seeing. If anybody can think of why this might be working, please enlighten me. My gut tels me it was the sort, but my gut hasn't been correct much lately.
I may be using it incorrectly but i think i have it right. I load data into my UITableViewController like so.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
CoCoachAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell...
switch (indexPath.section) {
case 0:
[cell.textLabel setText:#"Click to add new rower"];
cell.textLabel.textAlignment = UITextAlignmentCenter;
break;
case 1:
[cell.textLabel setText:[[appDelegate teamRoster]objectAtIndex:indexPath.row]];
break;
}
return cell;
}
And everything works fine, i then push the user to a different viewController and allow them to enter their name into a text field. I take their name and add it into the same array that populated my UITableViewController, and from the UITableViewController i call:
[self.tableView reloadData];
But nothing happens. If i check my array i can see that it has the correct number of objects, and their name is the last entry, but the tableview remains unchanged...
I was thinking maybe i just dont know how to use reloadData, but from what i have been reading elsewhere this should be working.
Any thoughts?
Your crash is due to the fact that you are doing
NSLog(#"%#",[[appDelegate teamRoster] count]);
when you should be doing
NSLog(#"%d",[[appDelegate teamRoster] count]);
Using %# sends the objec the message description, which does not work for ints (or floats or BOOLs).
The NSLog crashes because you are using the wrong formatter type (#"%#"), it should be:
NSLog(#"%d",[[appDelegate teamRoster] count]);
Other than that, where is reloadData being called from? Make sure it's happening on the Main thread.
Looking for help on how to properly load the data for a Grouped Table View. I am using following code to load the data which I think should prepare an array "details" for "cellForRowAtIndexPath". However when I run the program I get the same data for all groups and it happens to be the last row in my data (which is in an NSArray called "Users"). Obviously I am doing something wrong but not sure what... please help.
// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
NSRange aRange;
aRange.length = 9; aRange.location = 16;
NSString *users = [self.Users objectAtIndex: section];
NSString *subtitle = [NSString stringWithString:[users substringWithRange:aRange]];
details = [[NSArray arrayWithObjects:subtitle, subtitle, subtitle, nil] retain];
return [details count];
}
The data loading routine is as follows:
- (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];
}
// Configure the cell.
UIImage *cellImage = [UIImage imageNamed:#"world.png"];
cell.imageView.image = cellImage;
cell.textLabel.text = [details objectAtIndex:indexPath.row];
return cell;
}
From what you've posted, details array is being reset every time the table views asks its data sources for the number of rows in a section. details is last set when -tableView:numberOfRowsInSection: is last called i.e. for the last section. Once set, the same array provides the data for cell.textLabel.text for all the sections. So you are getting incorrect data.
It would be appropriate to calculate and store all the details arrays in a different array, say detailsArray.
The data can then be accessed them like
[[detailsArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row]
Another problem with your code is that every time numberOfRowsInSection is called, data is being leaked as details is being reset without the earlier object being released.