Scrolling UITableview Application going to be crash? - iphone

Question

In my application I am using UITableview. In that TableView I am displaying an array that contains dictionaries. The last row of the TableView contains one button which indicates user load more events. If the user clicks on the button we need to get data from a service and load the data in the UITableview.
For that purpose I am trying to implement it like the code below:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section**
{
if (ifMore)
{
return [totalArray count];
}
else
{
return [tableArray count];
}
return 0;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
int count =[tableArray count];
if (ifMore)
{
count= [totalArray count];
}
if (indexPath.row==count-1)
{
return 96;
}
return 56;
}
The cell for row index method is:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
TableCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell = [[TableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
NSMutableDictionary *dict=[[NSMutableDictionary alloc]init];
if (ifMore)
{
dict=[totalArray objectAtIndex:indexPath.row];
}
else
{
dict =[tableArray objectAtIndex:indexPath.row];
}
cell.hostLabel.text=[dict objectForKey:#"Event_Name"];
cell.startTime.text=[dict objectForKey:#"Event_Startdate"];
cell.endTime.text= [dict objectForKey:#"Event_Enddate"];
cell.accessoryType=UITableViewCellAccessoryDisclosureIndicator;
int count=[tableArray count];
if(ifMore)
{
count=[totalArray count];
}
if (indexPath.row==count-1)
{
[cell.contentView addSubview:moreBtn];
}
return cell;
}
I am using the code like this. Now my main problem is when I am loading data normally it is good does not make any issue while loading scrolling. Its works perfectly. But when I am clicking on the button in the TableView cell and get data from service and reload data. It works fine. But when I am scrolling it crashes. I am stuck with this.
The crash message is:
2012-12-20 12:22:49.312 IAGDapp[3215:15e03] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 4 beyond bounds [0 .. 3]'
*** First throw call stack:
(0x4b5052 0x21c7d0a 0x4a1db8 0x2b9e6 0x2b7d2 0xc80a57 0xc80b92 0xc8669e 0x7402db 0x7401af 0x489966 0x489407 0x3ec7c0 0x3ebdb4 0x3ebccb 0x1f6b879 0x1f6b93e 0xc2ba9b 0x28e0 0x2105 0x1)
terminate called throwing an exceptionsharedlibrary apply-load-rules all
kill
Can you help me find the error(s)?

Answer 1

Here when you click on UIButton of cell after here you get another data from services and after you want to load this data in same table so here follow this step..
first when you get data then add this data in your tableArray and totalArray also.
after that reload table.
Its crash because here numberOfRows and other methods are not found this new updated array.

Answer 2

I agree with Paras on this one. I can't see the part where you fetch the data into arrays but if you omit properly reloading data/ getting the data from the wrong array/ setting ifMore variable, your app will crash. First you should check them. If you think nothing is wrong, set a breakpoint inside numberOfRowsInSection and see why it returns 4 where you want to have 4+ cells.
But actually, I dont think you need two different arrays and ifMore variable for that purpose. Have a single array, update it after you fetch the data, reload the table and remove totalArray and all the if statements with ifMore variable. Simplicity may help with stability.

Answer 3

The problem is your loop.
if (indexPath.row==count-1)
{
return 96;
}
Count of your array is 4 and you are trying to load 96 rows in your tableview. Hence, your application is getting crash.
Problem is not scrolling UITableView. Problem is with loading the array in table.

Answer 4

Seems like ifMore variable is not working as you were expecting. Since the error log was index 4 beyond bounds [0 .. 3], it is clear that, the tableview's datasource contains 3 elements only, but the count you returned in numberOfRowsInSection were 4.
As an alternate solution, if you want your More button always as last row in your datasource, why cant you do it using single array. Just return the tableArray.count + 1(for more button) in numberOfRowsInSection method. In cellForRowAtIndexPath, check whether if the index was above tableArray.count, then create button. Same as in heightForRowAtIndex method too.