Memory Management in iPhone?

Question

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view {

UILabel *retval = (id)view;

if (!retval) {
    retval= [[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)];
}

NSDictionary *destination = [appDelegate.destinations objectAtIndex:row];
retval.text = [destination objectForKey:@"name"];
retval.font = [UIFont systemFontOfSize:18];
return retval;
}

See the mothod, After doing Product > Analyze in XCode, I will get the following warning at line number

return retval;

Potential leak of an object allocated on line 213 and stored into 'retval'

Let me know, what is this, how would I do release,

Please edit this code, and explain me what have you changed in it, Thanks

Answer 1

retval is an UILabel that you allocate but never release. Usually, you would create it as

retval= [[[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)] autorelease];

and in the calling method, add it to a view or whatever.

Answer 2

Just when you allocate the label, keep it in autorelease mode, as you'll need to release RETVAL somewhere. You haven't released it, hence a leak is found.

retval= [[[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)]autorelease];