Question

I am running into a crazy problem when dealing with the UITableView, do you have any good sample projects (github) or tutorials that show how to do a multiple selections(checking) on a sectioned UITableView, i mean a long UITableView where the user can scroll up and down it and select/deselect the cells in different sections.
The problem i ran is concerning checking cells in different sections, and scrolling up and down the table view. The app crashes, and in a better case, i get random cells checked when i scroll down and up the screen (the table view). So i decided to make a simple project in which i try all that before integrating it into my app.

One of the suit of actions that give rise to the crash is: check cell1 in section1 and check cell2 in section2, then uncheck cell1 in section1.
The sample is here, please test it, it’s too lightweight, tracking the crash with breakpoint, i found that this method is causing the issue:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    NSDictionary *dict = [self.tableData objectAtIndex:[self tableIndexFromIndexPath:indexPath]];//this statement is the issue, i think the app is conflicting between sections when check/uncheck cells
    BOOL newState = ![[dict objectForKey:kCellStateKey] boolValue];
    NSDictionary *newDict = [NSDictionary dictionaryWithObjectsAndKeys:[dict objectForKey:kCellTextKey], kCellTextKey, [NSNumber numberWithBool:newState], kCellStateKey, nil];
    [self.tableData replaceObjectAtIndex:indexPath.row withObject:newDict];

    [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationNone];
}

I really need your expertise to improve my code. Thanx in advance.

Answer 1

The table does not like replacing the DICTs for some reason even when allocated correctly, This will work.

1) Change all Dicts to MutableDicts

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath 
{
    NSMutableDictionary *dict = [self.tableData objectAtIndex : [self tableIndexFromIndexPath : indexPath]];

    BOOL newState = ![[dict objectForKey:kCellStateKey] boolValue];

    [dict setValue :[NSNumber numberWithBool:newState] forKey : kCellStateKey];

    NSArray *test = [[NSArray alloc]initWithArray : [NSArray arrayWithObject:indexPath] ];

    [tableView reloadRowsAtIndexPaths : test withRowAnimation:UITableViewRowAnimationNone];
}