UITableViewCell is being reused but I can't work out why? - iphone

Question

I've got a tableview loaded from an array and for some reason it's re-using the cell but loading the same information lower down the table, a second time.
http://screencast.com/t/Ig8bcqSpLzp
The video above should give you an idea of what I mean.
This is my code to load the cell:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
}
accessicon *current =[arryAccess objectAtIndex:indexPath.row] ;
cell.textLabel.text = current.text;
cell.imageView.image = [UIImage imageNamed: current.iconPath];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
mySwitch *switchView = [[mySwitch alloc] initWithFrame:CGRectZero];
cell.accessoryView = switchView;
switchView.myValue = current.iconValue;
if(totalIconValue & current.iconValue) {
[switchView setOn: YES animated:NO];
} else {
[switchView setOn: NO animated:NO];
}
[switchView addTarget:self action:#selector(switchChanged:) forControlEvents:UIControlEventValueChanged];
[switchView release];
return cell;
}
Any help will be appreciated
EDIT: I've updated my code above, however on the actual device it's still selecting items it shouldn't be - no longer reusing the names but if i scroll up and down it selects them on it's own?
see the video here: http://screencast.com/t/a9N1qbws
Tom

Answer 1

This code:
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
if (cell == nil) {
...
is fundamentally wrong. It should read:
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
...
And then, anything that is row-specific should be outside that if statement.
The pattern for this, generally, should be:
dequeue a reusable cell
if you didn't get one:
allocate a new cell
perform generic cell setup, i.e. setup that applies to all cells
setup the cell for the specific row, and return it.
Hope this helps.

Answer 2

You aren't reusing you cells. And you are filling the cells only when the init fails. Try this code:
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
}
accessicon *current =[arryAccess objectAtIndex:indexPath.row] ;
cell.textLabel.text = current.text;
cell.imageView.image = [UIImage imageNamed: current.iconPath];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
mySwitch *switchView = [[mySwitch alloc] initWithFrame:CGRectZero];
cell.accessoryView = switchView;
switchView.myValue = current.iconValue;
if(totalIconValue & current.iconValue) {
[switchView setOn: YES animated:YES];
} else {
[switchView setOn: NO animated:YES];
}
[switchView addTarget:self action:#selector(switchChanged:) forControlEvents:UIControlEventValueChanged];
[switchView release];
Or develop under ios5 and get rid of the alloc and init.

Answer 3

You are constantly creating new rows instead of reusing the old ones.
Move the line
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
inside the if block, end move everything else you have in the if block outside of it, except the lines
mySwitch *switchView = [[mySwitch alloc] initWithFrame:CGRectZero];
cell.accessoryView = switchView;
You need to create the switch only once for row, when it is initialized (that means, in the if statement). I suggest you to create it and assign it a tag, so you can access it later by its tag. Your code now is creating a new switch everytime the cell is used, this could be the reason why the switches are behaving this way.