MainTarBarController這個(gè)改為要返回的控制器
UIViewController * presentingViewController = self.presentingViewController;
do {
if ([presentingViewController isKindOfClass:[MainTarBarController class]]) {
break;
}
presentingViewController = presentingViewController.presentingViewController;
} while (presentingViewController.presentingViewController);
[presentingViewController dismissViewControllerAnimated:YES completion:nil];
