Where to addObserver to NSNotificationcenter in a custom UITableViewCell?

Question

In my UITableViewCell I have a method initNotification which is called by the TableViewController in cellForRowAtIndexPath where the TableCells are created.

My Problem is that, every time this view is reloaded, the initNotification method is called again, so when the Notification appears, the NotificationHandle is called x-times!

I have tried to remove the Observer before adding it again with:

-(void) initNotification{
    [[NSNotificationCenter defaultCenter] removeObserver:self];

    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(handleNotificationOnOff:)
     name:[[NSString alloc] initWithFormat:@"%@",[self.light beckhoffOnOff]]
     object:nil];
}

but this do not work either. The Problem is, I cannot use a bool-flag or anything like that, because the Cells are always reinitialized by the ViewController.

Is there a proper way to remove the NotificationHandle form the NotificationCenter?

edit: This is how I create my custom TableViewCells

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell;
    Light* l = [[staticModel.model getRoomAtIndex:[indexPath section]]getLightAtIndex:[indexPath item]];
    if([l typ]==ONOFF){
        TableCellLight *conof = [tableView dequeueReusableCellWithIdentifier:@"ReuseIDOnOff" forIndexPath:indexPath];
        LightOnOff *lonof = (LightOnOff*) l;
        [[conof label] setText: [lonof bezeichnung]];
        conof.light=lonof;

        [conof initNotification];
        cell = conof;
    }
   if([l typ]==DIMMER){
        TableCellLightDim *cdim = [tableView dequeueReusableCellWithIdentifier:@"ReuseIDDim" forIndexPath:indexPath];

        LightDim *ldim= (LightDim*) l;
        [[cdim label] setText: [ldim bezeichnung]];
        [[cdim slider]setValue:[ldim dimVal]];
        cdim.light=ldim;
        [cdim initNotification];
        cell = cdim;
    }
    if([l typ]==RGB){
        TableCellLightRGB *crgb = [tableView dequeueReusableCellWithIdentifier:@"ReuseIDRGB" forIndexPath:indexPath];
        LightRGB *lrgb= (LightRGB*) l;
        [[crgb label] setText: [lrgb bezeichnung]];
        crgb.light=lrgb;
        crgb.owner=self;
        [crgb initNotification];
        cell = crgb;
    }

    return cell;
}

Thanks

Answer 1

Generally speaking the cell shouldn't be observing anything. The controller should be observing changes and pushing the updated information onto the cells.

Calling removeObserver: before adding the observer should work. If you were going to do anything in prepareForReuse or tableView:didEndDisplayingCell:forRowAtIndexPath: to reset the cell, that would be the code you use. You need to look at how you tested that it wasn't working and how you're reusing cells.