多个Storyboard切换

- (void)showStoryboard
{
    // 实例化MainStoryboard
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];

    // 在主线程上更新Storyboard
    dispatch_async(dispatch_get_main_queue(), ^{

        self.window.rootViewController = storyboard.instantiateInitialViewController;
    });
}