Where should i be using removeFromSuperview in relation to adding views to a table?

Question

Hi guys,

I have a little table that works pretty well. But I was told to remove my subviews at some stage incase the call to drawn the table happens again for whatever reason. I was told it can be handled using removeFromSuperview.

Where and how should i handle this? I need to use tags to identify the cells or views?

Here is my code to create my views.

- (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 setFont:[UIFont systemFontOfSize:10.0]];

if (indexPath.row == 0) 
{
    [cell setText:@"Show only Airports"];
    showAirportsOnlySegment = [ [ UISegmentedControl alloc ] initWithFrame: 
CGRectMake(100, 4, 80, 28) ];
    [ showAirportsOnlySegment insertSegmentWithTitle: @"Yes" atIndex: 0 
animated: NO ];
    [ showAirportsOnlySegment insertSegmentWithTitle: @"No" atIndex: 1 animated: 
NO ];
    showAirportsOnlySegment.selectedSegmentIndex = 0;
    showAirportsOnlySegment.segmentedControlStyle = UISegmentedControlStyleBar;
    showAirportsOnlySegment.tag = 1;
    showAirportsOnlySegment.enabled = YES;
    [showAirportsOnlySegment addTarget:self action:@selector(airConOnOffAction:) 
forControlEvents:UIControlEventValueChanged];
    [ cell addSubview: showAirportsOnlySegment ];
    [self.view bringSubviewToFront:showAirportsOnlySegment];        
    [showAirportsOnlySegment release];
} 
else if (indexPath.row == 1) 
{
    [cell setText:@"Air Con?"];     
    airConSegment = [ [ UISegmentedControl alloc ] initWithFrame: 
CGRectMake(100, 4, 80, 28) ];
    [ airConSegment insertSegmentWithTitle: @"Yes" atIndex: 0 animated: NO ];
    [ airConSegment insertSegmentWithTitle: @"No" atIndex: 1 animated: NO ];
    airConSegment.selectedSegmentIndex = 0;
    airConSegment.segmentedControlStyle = UISegmentedControlStyleBar;
    airConSegment.tag = 2;
    [airConSegment addTarget:self action:@selector(airConOnOffAction:) 
forControlEvents:UIControlEventValueChanged];
    airConSegment.enabled = YES;
    [ cell addSubview: airConSegment ];
    [self.view bringSubviewToFront:airConSegment];
    [airConSegment release];
}   
return cell;
}

Can anybody advise how to handle the remove the subviews?

Many THanks -Code

Answer 1

I guess that you want to customize your first and second row. However, the cell might got reused because you are using dequeueReusableCellWithIdentifier, so your custom subviews might reappear again in other row if you don't clean up your cell properly after dequeuing. In this case I would suggest that you keep your subviews in instance variables, says view1 and view2, and after dequeuing you just do:

if (view1.superview == cell) {
    [view1 removeFromSuperview];
    [view1 release];
}
else if (view2.superview == cell) {
    [view2 removeFromSuperview];
    [view2 release];
}

then your subview will not appear in the reused cell.