UITabBar 控制器给出以前选择的索引? [英] UITabBar controller gives previous selected index?

问题描述

我在应用程序中使用自定义 UITabBarController 来检查选定的索引.当我选择 selectedIndex 时，我有这个方法来触发:

I'm using Custom UITabBarController in the app to check selected index. I've this method to trigger when I select the selectedIndex:

override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {

 //   print(self.selectedIndex)

    switch self.selectedIndex {
    case 1:

        print("should load feed " + String(self.selectedIndex))
        (self.viewControllers![1] as?  PageViewController)?.downloadNews()
   case 2:
        print("should load saved" + String(self.selectedIndex))
        (self.viewControllers![2] as? SavedController)?.loadData()
    default:
        return
    }
}

但是，当我单击新的标签栏项目时，我会得到旧的选定索引.我知道这是很容易的任何想法.这种方法有没有办法取出正确的索引?

However I get old selected index when I click the new tab bar item. I know it's something easy any idea. Is there a way to takeout the right index in this method?

推荐答案

实际上 selectedIndex 在 didSelect 发生之前不会改变.商品索引应取自商品本身.

Actually selectedIndex is not changed until didSelect happens. Item index should be taken from the the item itself.

override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem)
{ 
   let indexOfTab = tabBar.items?.index(of: item)
   print("pressed tabBar: \(String(describing: indexOfTab))")
}

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