Adding Activity indicator programatically as sub view

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
     [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
   
    self.view.userInteractionEnabled=NO;
     UIActivityIndicatorView* indicator = [[UIActivityIndicatorView alloc] init];
    indicator.activityIndicatorViewStyle=UIActivityIndicatorViewStyleWhiteLarge;
    //indicator.color=  [UIColor  colorWithRed:0.655 green:0.729 blue:0.812 alpha:1.0];
    indicator.color=  [UIColor whiteColor];
    [indicator setFrame:CGRectMake(150, 170, 20, 20)];
    [self.view addSubview:indicator];
    [indicator startAnimating];
   
}

//Where the indicator needs to stop

[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[indicator stopAnimating];