Activity Indicators when pushing next view - didSelectRowAtIndexPath

I can successfully push only next view in my iPhone app. However, cause the next view retrieves data to populate the UITableViews, sometimes waiting time could be a few seconds or slightly开发者_运维百科 longer depending on connection.

During this time, the user may think the app has frozen etc. So, to counter this problem, I think implementing UIActivityIndicators would be a good way to let the user know that the app is working.

Can someone tell me where I could implement this?

Thanks.

pushDetailView Method

- (void)pushDetailView {

[tableView deselectRowAtIndexPath:indexPath animated:YES];
//load the clicked cell.
DetailsImageCell *cell = (DetailsImageCell *)[tableView cellForRowAtIndexPath:indexPath];

//init the controller.
AlertsDetailsView *controller = nil;
if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad){
    controller = [[AlertsDetailsView alloc] initWithNibName:@"DetailsView_iPad" bundle:nil];
} else {
    controller = [[AlertsDetailsView alloc] initWithNibName:@"DetailsView" bundle:nil];
}

//set the ID and call JSON in the controller.
[controller setID:[cell getID]];

//show the view.
[self.navigationController pushViewController:controller animated:YES];

You can implement this in didSelectRowAtIndexPath: method itself.

UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle: UIActivityIndicatorViewStyleWhiteLarge];
cell.accessoryView = spinner;
[spinner startAnimating];
[spinner release];

This will show the activity indicator at the right side of the cell which will make the user feel that something is loading.

Edit: If you set the accessoryView and write the loading code in the same method, the UI will get updated only when all the operations over. A workaround for this is to just set the activityIndicator in the didSelectRowAtIndexPath: method and call the view controller pushing code with some delay.

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {  

    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle: UIActivityIndicatorViewStyleWhiteLarge];
    cell.accessoryView = spinner;
    [spinner startAnimating];
    [spinner release];

    [self performSelector:@selector(pushDetailView:) withObject:tableView afterDelay:0.1];
}

- (void)pushDetailView:(UITableView *)tableView {

    // Push the detail view here
}