iOS TableView loads data very slowly

Question

I'm working on a project that parse data from web service and shows in a table view. Everything is ok, but I'm not satisfied with the performance of tableview. After parsing data form web I called reload data to show the data, But it is not showing cells immediately. It shows the data after 10/15 seconds later. I've checked all data's are loaded before I called reload data. And the strange thing is that it shows the cells immediately if I try to drag the table.

Any idea?

Update

-(void)receivedCategories:(NSMutableArray *)categoryItems{
  [self.spinner stopAnimating];
  self.categories=categoryItems;
  if (self.tableView!=nil) {
    [self.tableView reloadData];
  }
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
  return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
  return [self.categories count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
  static NSString *CellIdentifier = @"CategoryCell";
  CategoryCell    *cell           = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
  cell.category                   = [self.categories objectAtIndex:indexPath.row];
  return cell;
}

CategoryCell.m

@implementation CategoryCell

- (void)setCategory:(Category *)category
{
  [self.categoryTitle setText:category.title ];
  [self.categorySubTitle setText:category.description];
}

@end

Answer 1

It seems you're not calling [self.tableView reloadData]; from the main thread and that could be the cause of your problem.

You could try:

[self.tableView performSelectorOnMainThread:@selector(reloadData) withObject:nil waitUntilDone:YES];

Also check the accepted answer here for more info.