Activity Indicator within UINavigationBar

I've read a few answers about this particular topic, but for some reason, my code doesn't seem to work. It's within the UISearchBarDelegate delegate method -(void)searchBarSearchButtonClicked:(UISearchBar *)searchBar

UIActivityIndicatorVi开发者_JAVA百科ew *activityIndicator = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];
UIBarButtonItem *activity = [[UIBarButtonItem alloc] initWithCustomView:activityIndicator];
[[self navigationItem] setRightBarButtonItem:activity];
[activity release];
[activityIndicator startAnimating];

Any help or suggestions are much appreciated!

I believe the designated initializer for UIActivityIndicatorView is initWithActivityIndicatorStyle:. Try creating activityIndicator like this.

UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];

try this

UIView *view_actviti = [[UIView alloc] initWithFrame:CGRectMake(6,310,59,32)];
    UIActivityIndicatorView *act =[[UIActivityIndicatorView alloc] init];
    act.frame=CGRectMake(0, 0, 30, 30);
    UIBarButtonItem *actItem = [[[UIBarButtonItem alloc] initWithCustomView:view_actviti] autorelease];
    [view_actviti addSubview:act];
    self.navigationItem.rightBarButtonItem = actItem;
    [act startAnimating];

try this:

UIActivityIndicatorView *activityIndicator = 
    [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];
UIBarButtonItem * barButton = 
    [[UIBarButtonItem alloc] initWithCustomView:activityIndicator];

[[self navigationItem] setRightBarButtonItem:barButton];

[barButton release];
[activityIndicator startAnimating];

Also use this for stopping and removing activityIndicator:

[[self navigationItem] setLRightBarButtonItem:nil];
[activityIndicator stopAnimating];
[activityIndicator release];