how to set UITableviewcell or UITableview as Empty?

Question

Hi, i am using rss feed.first time ,table view has no rows.if i press button, there will come values.if i press again ,the table view has previous values.after recieving data it disappears and new data will come there.but when i press button ,there cannot be previous value.i want to
remove it.How can i do it? any help?

Answer 1

When you need to update the contents of your UITableView call [tableView reloadData] method. So if by that time you've cleared your previous data from your data source then the table must get empty.

Answer 2

The UITableView works by a datasource. I'm going to assume that you have followed Apple's way of setting up a tableview which should look something like this:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath;
{   
    static NSString *identifier = @"identifier";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];

    if (cell == nil) {
     cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier] autorelease];
    }

    cell.textLabel.text = [_tableViewData objectAtIndex:[indexPath row]];

    return cell;
}

In this example the data for the UITableView is stored in the tableViewData array. Which is initialized like:

_tableViewData = [[NSArray arrayWithObjects:@"cell 1", @"cell 2", @"cell 3", @"cell 4", nil] retain];

So when you want to update the values of the tableview to something new you need to change the value of the tableViewData array and call reloadData on the table view.

_tableViewData = [[NSArray arrayWithObjects:@"new cell 1" , @"new cell 2", @"new cell 3", @"new cell 4", nil] retain];
[_tableView reloadData];