UIswitch in a table cell reused - ios

Question

I have a problem with uiswitch in my UITableViewCell that whenever i change a switch value in a specific cell that belongs to a specific section. All other sections cells that have same inexPath.row change . Please help ?
Here is my code of cellForRowAtIndexPath method:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
//UISwitch *switchview = nil ;
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifier];
}
UISwitch *switchController = [[UISwitch alloc] initWithFrame:CGRectZero];
CGRect switchFrame = switchController.frame;
NSString *str = [[self.SwitchArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
NSLog(#"string in cell%#", str);
//set its x and y value, this you will have to determine how to space it on the left side
switchFrame.origin.x = 50.0f;
switchFrame.origin.y = 10.0f;
switchController.frame = switchFrame;
[switchController addTarget:self action:#selector(switchChanged:) forControlEvents:UIControlEventValueChanged];
[cell addSubview:switchController ];
[addSubview:switchController];
if ([[[self.SwitchArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row ]isEqualToString:#"ON"])
{
switchController.on=YES;
}
else
{
switchController.on=NO;
}
return cell;
}
And here is SwitchChangedEvent:
-(void)switchChanged:(UISwitch *)sender
{
UITableViewCell *cell = (UITableViewCell *)[sender superview];
NSIndexPath *index=[mainTableView indexPathForCell:cell];
if (sender.on)
{
[[self.SwitchArray objectAtIndex:index.section] replaceObjectAtIndex:index.row withObject:#"ON"];
NSString *word= [[self.mainArray objectAtIndex:index.section ] objectAtIndex:index.row];
}
else
{
//call the first array by section
[[self.SwitchArray objectAtIndex:index.section] replaceObjectAtIndex:index.row withObject:#"OFF"];
NSString *word= [[self.mainArray objectAtIndex:index.section ] objectAtIndex:index.row];
}
[padFactoids setObject:[NSKeyedArchiver archivedDataWithRootObject:SwitchArray] forKey:#"savedArray"];
[padFactoids synchronize];
}

Answer 1

You have two main problems:
This code is wrong:
[cell addSubview:switchController ];
Never add a subview to the cell; add it only to the cell's contentView.
You are adding the switch every time through cellForRowAtIndexPath:. But these cells are being reused. So some cells already have the switch. Thus you are adding many switches to some cells.

Answer 2

As already pointed out by others, you're adding multiple switches to each cell. FTFY:
UISwitch *switchController = nil;
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifier];
switchController = [[UISwitch alloc] initWithFrame:CGRectZero];
switchController.tag = 'swch';
CGRect switchFrame = switchController.frame;
//set its x and y value, this you will have to determine how to space it on the left side
switchFrame.origin.x = 50.0f;
switchFrame.origin.y = 10.0f;
switchController.frame = switchFrame;
[switchController addTarget:self action:#selector(switchChanged:) forControlEvents:UIControlEventValueChanged];
[cell.contentView addSubview:switchController];
}
else
{
switchController = (UISwitch*)[cell.contentView viewWithTag: 'swch'];
NSAssert(switchController != nil, #"how?");
}
NSString *str = [[self.SwitchArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
NSLog(#"string in cell%#", str);
switchController.on = [str isEqualToString:#"ON"];
return cell;

Answer 3

If you look, I think you will find that you are building up multiple switches and on each cell.
As cells get reused, you add a new switch but do not remove the old one. I think this my be at least part of the cause of your problem.
UPDATE
I think I would handle this a bit differently than others. I think it will be easier for #AlanoudAldrees to remove the old switch.
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifier];
}
else
{
for (UIView *view in cell.subviews)
if ([view isKindOfClass:[UISwitch class]])
[view removeFromSuperview];
}