重新加载tabbar的主控制器

              //先dismiss或者pop出来,
              //[self dismissViewControllerAnimated:YES completion:nil];

                UIWindow *aWindow = [UIApplication sharedApplication].delegate.window;
                UITabBarController *rootVC = (UITabBarController *)aWindow.rootViewController;
                for (UINavigationController *nav in rootVC.viewControllers) {
                    if (nav && [nav isKindOfClass:[UINavigationController class]]) {
                        for (XXXViewController *xxxVC in nav.viewControllers) {
                            if (xxxVC && [xxxVC isKindOfClass:[XXXViewController class]]) {
                                
                                [xxxVC removeFromParentViewController];
                                /**
                                 加载一个新的tabbar主页控制器
                                 */
                                XXXViewController *vc = [[XXXViewController alloc] init];
                                vc.albumImgStr = imageFolderPath;
                                vc.tabBarItem.imageInsets = UIEdgeInsetsMake(6, 0, -6, 0);
                                UIImage *selectImgH = [UIImage imageNamed:@""];
                                [vc.tabBarItem setImage:[selectImgH imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
                                [vc.tabBarItem setSelectedImage:[[UIImage imageNamed:@""] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
                                [nav setViewControllers:@[vc] animated:NO];
                                break;
                            }
                        }
                    }
                }

                 //返回指定的tabbar主界面去
                rootVC.selectedIndex = 2;