點擊按鈕使用線程執行UIActivityIndicatorView

@interface ViewController : UIViewController 
{
UIActivityIndicatorView *ActivityView;
}
-(void)ActivityLoad;
-(IBAction)ClickSubmit:(id)sender;
@end



-(void)ActivityLoad
{
    ActivityView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    [ActivityView setCenter:CGPointMake(320/2.0, 480/2.0)]; // I do this because I'm in landscape mode 
    // spinner is not visible until started
    [self.view addSubview:ActivityView];
    [ActivityView release];
    [ActivityView startAnimating];
}



-(IBAction)ClickSubmit:(id)sender
{ 
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    [NSThread detachNewThreadSelector:@selector(ActivityLoad) toTarget:self withObject:nil];
	//.…
    [pool release];[ActivityView stopAnimating];
}