是否可以在Objective C中打开正在运行的后台应用程序

在特定时间从后台打开我的应用.

open my app from background running on a specific timing..

想做这样的事

 - (void)applicationDidEnterBackground:(UIApplication *)application
{
  timer = [NSTimer scheduledTimerWithTimeInterval:10
                                                      target:self
                                                    selector:@selector(timerFired:)
                                                    userInfo:nil
                                                     repeats:NO];
}

- (void)timerFired:(NSTimer*)timer
{

NSLog( @"yes it is running...");
PickUpCallViewController  *call=[[PickUpCallViewController alloc]initWithNibName:@"PickUpCallViewController" bundle:nil];

navi=[[UINavigationController alloc]initWithRootViewController:call];
[[navi navigationController] setNavigationBarHidden:YES animated:YES];
window.rootViewController = navi;

[window makeKeyAndVisible];
}