Question

Something weird is going on with my tableview when changing data. I have something like this:

// fadeout existing data
... // change data (new values for the cells are blank)
for{ // loop all rows
[TableView reloadRowsAtIndexPaths: withRowAnimation:]; // smooth fade out
}

// add one new row to the table
... // change data (just add one new row but leave the cells empty)
[TableView reloadData] // reload all of the data (new row should be added)

... // change data (just add values to the existing cells)
for{ // loop all rows
[TableView reloadRowsAtIndexPaths: withRowAnimation:]; // smooth fade in
}

In theory, at least what I think, this should work. But I had some glitches so I added NSLogs in the for loops and in the: - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath so I noticed that my [tableView reloadData] executes after the first row of fade in loop!@#

I was thinking about making some kind of a delay between reloadData and fade in loop, but I don’t want to force it to work, I want it to work properly.

• Is there a better way to accomplish what I’m trying to do?
• Can I dynamically add one row at the bottom of the table without calling the ‘reloadData’ method?

Thanks.

Answer 1

Yes, just use the tableView insertRowsAtIndexPaths method, which will then call your dataSource to load those new rows.

To load a single row at the end of your table, you’d first update your data source to include the new row, then generate the indexpath using:

NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[yourdata count]-1 inSection:0];
NSArray *indexPaths = [NSArray arrayWithObject:indexPath];
[tableView insertRowsAtIndexpaths:indexPaths withRowAnimation:whateveryouwant];

Remember, that will immediately call your tableView:cellForRowAtIndexPath method, so update your dataSource to include the extra row before inserting the new row into your table, and be careful that the row index in the indexPath you specify matches the newly added item in your data source.