iOS 第二次点击TabBar刷新界面操作

1.在UITabBarController中设置delegate
2.实现方法

- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController

3.最终代码

- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController{
    if ([tabBarController.viewControllers containsObject:tabBarController.selectedViewController]) {
        if ([viewController isEqual:tabBarController.selectedViewController]) {
            NSLog(@"这里执行操作");
            return NO;
        }
    }
    return YES;
}