loading symbol not appearing on button click - iphone

Question

-(IBAction)addtocontacts:(id)sender
{
HUD = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
HUD.labelText = NSLocalizedString(#"Saving_data", #"");
//added my validation here
[self performSelectorInBackground:#selector(insertDetails) withObject:nil];
}
-(void) insertDetails
{
//save contact details in database
[HUD hide:YES];
UIAlertView *alertview=[[UIAlertView alloc]initWithTitle:#"" message:#"Contact account details added" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil, nil];
[alertview show];
}
I have added loading symbol on SaveButton click.I am not getting loading symbol.How do I make it appear until I get alert message.

Answer 1

Add HUD on top most layer. Example if you have tableview on top of view. Then add it on tableview. In my case I am adding HUD on tableviews and its working fine

Answer 2

it is because you are instantly hiding the HUD in insertDetails.
-(IBAction)addtocontacts:(id)sender
{
HUD = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
HUD.labelText = NSLocalizedString(#"Saving_data", #"");
//added my validation here
[self performSelectorInBackground:#selector(insertDetails) withObject:nil];
}
-(void) insertDetails
{
//save contact details in database
// [HUD hide:YES]; remove it
UIAlertView *alertview=[[UIAlertView alloc]initWithTitle:#"" message:#"Contact account details added" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil, nil];
[alertview show];
}
and instead download the newer version of MBProgressHUD and use the following Method
- (IBAction)addtocontacts:(id)sender {
// The hud will dispable all input on the view (use the higest view possible in the view hierarchy)
HUD = [[MBProgressHUD alloc] initWithView:self.navigationController.view];
[self.view addSubview:HUD];
// Regiser for HUD callbacks so we can remove it from the window at the right time
HUD.delegate = self;
// Show the HUD while the provided method executes in a new thread
[HUD showWhileExecuting:#selector(myTask) onTarget:self withObject:nil animated:YES];
}
and implement the delegate method.
MBProgressHUDDelegate methods
- (void)hudWasHidden:(MBProgressHUD *)hud {
// Remove HUD from screen when the HUD was hidded
[HUD removeFromSuperview];
[HUD release];
HUD = nil;
}