When I start typing word for example if type "A" it is not taking that pass to modal class but I type "AA"than take only 1st word why?

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
  if(IndustryTextField == textField && textField.text.length!=0)
  {
      [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(Customer_search:) name:@"Customer_search" object:nil];
      [NSThread detachNewThreadSelector:@selector(showLoadingIndicator:) toTarget:appDelegate withObject:nil];
      Modalclass *CCSM = [[Modalclass alloc]init];
      [CCSM SendRequest_Search_Customer:textField.text];
  }
    return YES;
}

even not getting the same issue with this  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textDidChange:) name:UITextFieldTextDidChangeNotification object:nil];