行删除不会刷新iOS应用程序中的表格视图

Question

I have spent hours searching for the solution with out any luck. I am trying to delete a row (also deselect same row) programmatically. After row deletion call below, UITableViewDelgate methods get called expectedly and data source is updated but UITableView is not refreshed. deselectRowAtIndexPath call also does not work. I tried all kinds of scenarios as shown by commented lines.

Here is my code: checkoutPerson is called as a result of observer listening for NSNotificationCenter messages.

- (void) checkoutPerson: (NSNumber*) personId {
Person *person = [_people objectForKey:personId];
if( person )
{
    // Remove person from data source
    int rowIndex = person.rowIndex;
    S2Log(@"Deleting row number=%d", rowIndex);
    [_allKeys removeObjectAtIndex:rowIndex];
    [_people removeObjectForKey: personId];
    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:rowIndex inSection:0];

    //[[self tableView] beginUpdates];
    [self.tableView deselectRowAtIndexPath:indexPath animated:YES];
    S2Log(@"Deleting indexPath row=%d", [indexPath row]);
    [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
                    withRowAnimation:UITableViewRowAnimationFade];
    //[[self tableView] endUpdates];
    S2Log(@"Reloading data");
    //[[self tableView] reloadData];
    //[self performSelector:@selector(refreshView) withObject:nil afterDelay:1.5];
    //[self.tableView performSelectorOnMainThread:@selector(reloadData) withObject:nil waitUntilDone:YES];
}

}

I will appreciate for help. Thanks -Virendra

I believe deleted cell is not being recycled. If I delete row in the middle, last row is always erased (since there is one less item) but the deleted row remains.

Answer 1

Use the above code between two function for table view

[tableView beginUpdates];

// the deletion code from data source and UITableView

[tableView endUpdates];

By calling this functions you are telling UITableView that you are about to make updates for deleting your cell.

Edit

The other problem I see with your code is you first delete the data from the data source.

Now you are asking for the UITableViewCell (which actually reloads the UITableView ) and then you are deleting the row from UITableView

I guess you should fetch the UITableViewCell before deleting values from your data source.

Answer 2

I found the problem. It has nothing to do with the code I posted above. It is syncing problem between visual display and the contents of data source. I have an embedded UITableView as part of a composite view. In composite view's controller, I was wiring up UITableView's delegate and data source to an instance of UITableViewController. Instead of this, I should have set UITableViewController's tableView property to the embedded UITableView. It seems that UITableView has to be contained within UITableViewController in order to correctly sync up table view visual display to the contents of data source. This also fixes row deselection and scrolling. I also needed to delay reloadData call in which case deleteRowsAtIndexPaths:withRowAnimation is not required. All you need is to modify the contents of your data source and call reloadData with a delay of 1.5 Seconds.

Thanks to all for great help.