在PresentModalView控制器之后等待

我需要在PresentModalView控制器之后等待(不要执行代码),直到模式视图被取消、可能或是概念错误?

-(NSDictionary *)authRequired
{
    //This view write the settings when dismissed (plist)
    [self presentModalViewController:loginRegView animated:YES]; 
    //Read from the setting file (plist) and send back (it's a delagate method)
    NSMutableDictionary *ret=[[NSMutableDictionary alloc] init];
    [ret setObject:[app.settings get:@"user"] forKey:@"user"];
    [ret setObject:[app.settings get:@"pass"] forKey:@"pass"];
    return ret;
}