Unable to update UITableView

Question

I have UITableViewController as the RootViewController. I need to add rows to the table depending on data I get from another thread which I initiate from the RootViewController's thread. When I retun back from other thread to my RootViewController's thread I have the updated data, But I can't update the TableView. I called the [self.tableview reloadData]; method but that doesnt seem to work. I also tried the [self.tableview setNeedsDisplay] call but with no success. How do I update the TableView with new data?

In my RootViewController Class I have:

- (void) reload {

for(int i=0;i<[camDetails count];i++)
 {
    cCameraInformation *obj = [[cCameraInformation alloc] init];
    obj = [camDetails objectAtIndex:i];
    NSString *tString = [[NSString alloc] initWithFormat: @"        Remote     %s     %s",[obj->sCameraid UTF8String],[obj->sCameraid UTF8String]];
    [tableEntry addObject:tString];
 }
 [self.tableView reloadData];
}

Then there is a receive class thread which is continuously receiving data. Its base class is NSObject. So, I used the Application delegate class ( which has an instance of RootViewController class ) to call this reload data method of the RootViewController class in my receive thread.

I am unable to invoke the above method using performSelectorOnMainThread.

Answer 1

hey are you sure you are updating the table view display / reloading tableview on the main thread? i faced the same problem, the data was in there but until user scrolls, tableview was not updated

upon googling i came to know you need to call the reloadData method on the main ui thread

code example below:

- (void) getDataOnNewThread
{
    // code here to populate your data source
    // call refreshTableViewOnMainThread like below:
    [self performSelectorOnMainThread:@selector(refreshTableView) withObject:nil waitUntilDone:NO];
}

- (void) refreshTableView
{
    [tableView reloadData];
}

Answer 2

Make sure you have the correct values being returned from numberOfRowsForSection for starters.

Also make sure your cellForRowAtIndexPath method is using this data to get the cell contents.

Your reloadData method should be called on the main thread, not on any other thread.

Will be able to help you better if you can post the relevant code.