IOS: ActivityIndicator over UITableView... How to?

Question

i want display an activity indicator over a uitableview while it's loading data (in another thread). So in the ViewDidLoad method of the UITableViewController:

-(void)viewDidLoad
 {
    [super viewDidLoad];

    //I create the activity indicator
    UIActivityIndicatorView *ac = [[UIActivityIndicatorView alloc]  
                      initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    [ac startAnimating];

    //Create the queue to download data from internet
    dispatch_queue_t downloadQueue = dispatch_queue_create("PhotoDownload",NULL); 
    dispatch_async(downloadQueue, ^{
      //Download photo
      .......
      .......
      dispatch_async(dispatch_get_main_queue(), ^{
         ......
         ......
         [ac stopAnimating];
      });
    });
   .......

Why the activity indicator don't display over the table view? How can i achieve it?

Answer 1

You need to add the UIActivityIndicatorView to something. You can add it to a UITableView header view. To do this you will need to provide your own custom view.

...
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 50)];
[view addSubview:ac]; // <-- Your UIActivityIndicatorView
self.tableView.tableHeaderView = view;
...