Default Checklist in UITableView - iphone

Question

I want to implement Checklist for a single selection in a UITableView. Also, I need a cell to be selected by default. Here's my implementation in cellForRowAtIndexPath:
NSUInteger row = [indexPath row];
NSUInteger oldRow = [lastIndexPath row];
cell.accessoryType = (row == oldRow && lastIndexPath != nil) ? UITableViewCellAccessoryCheckmark : UITableViewCellAccessoryNone;
if (indexPath.row == selectedRow ) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
didSelectRowAtIndexPath has this code:
if (!self.lastIndexPath) {
self.lastIndexPath = indexPath;
}
if ([self.lastIndexPath row] != [indexPath row])
{
UITableViewCell *newCell = [tableView cellForRowAtIndexPath: indexPath];
newCell.accessoryType = UITableViewCellAccessoryCheckmark;
UITableViewCell *oldCell = [tableView cellForRowAtIndexPath:self.lastIndexPath];
oldCell.accessoryType = UITableViewCellAccessoryNone;
self.lastIndexPath = indexPath;
}
else {
UITableViewCell *newCell = [tableView cellForRowAtIndexPath: indexPath];
newCell.accessoryType = UITableViewCellAccessoryCheckmark;
}
With this code I'm able to get a default checkmark, but whenever I select another row
the first one remains selected until I don't click that cell. So, If I want to select my desired result what should I do?
`

Answer 1

I think the code is a little too complicated. All you need is a single property:
NSInteger _selectedRow;
This, when initially defined, will provide a default selected row. And it will also maintain the previous selection (when looking for the cell to 'unselect'):
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CELL_IDENTIFIER];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CELL_IDENTIFIER];
}
if ([indexPath row] == _selectedRow) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
cell.textLabel.text = [NSString stringWithFormat:#"Row %d", indexPath.row];
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (_selectedRow >= 0) {
[tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:_selectedRow inSection:0]].accessoryType = UITableViewCellAccessoryNone;
}
_selectedRow = [indexPath row];
[tableView cellForRowAtIndexPath:indexPath].accessoryType = UITableViewCellAccessoryCheckmark;
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
When this view is created, if you assign:
_selectedRow = 1;
Then the second row will automatically be selected. A value of -1 indicates no default selection, and the two above methods will automatically add/remove the checkmarks from tapped rows.