不通过底部的工具栏跳转到指定的tabBar上

    AppDelegate *appDelegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
    UIViewController *controller = app.window.rootViewController;
    JCTabBarController *rvc = (JCTabBarController *)controller;
    [rvc setSelectedIndex:1];//需要跳转的tabBar的索引，tabBar默认的索引是从0开始的。
    [self.navigationController popToRootViewControllerAnimated:YES];