Xcode从顶级对象获取对象

Question

In my iOS app setup, I have a universal object (lets call it UniversalObj ) declared in the top level object. ( SampleAppDelegate in my case)

Within this, I have a UITabBarController containing two UIViewController (which I want to have access to UniversalObj .

In SampleAppDelegate , I have tried the following to pass UniversalObj to it:

MyViewController *vc = (MyViewController *) [self.tabBarController.viewControllers.objectAtIndex:0];
[vc setMyObj:self.universalObject];

The problem with this is that when I do this, sometimes, the view hasn't loaded yet so MyViewController.myObj==null .

Now, I am trying to access SampleAppDelegate (of type NSObject ) from MyViewController . I can get to the UITabBarController using: ***self.parentViewController*** , but I don't know how to get to SampleAppDelegate .

How can I access UniversalObj in SampleAppDelegate from MyViewController ? How can I change the self.parentViewController line in MyViewController to get to SampleAppDelegate ? Or is there a better way to do this?

Thanks in advance for your help.

Guvvy

Answer 1

您将使用-[UINib instantiateWithOwner:options:] ：

NSArray * topLevelObjects = [nib instantiateWithOwner:pwner options:options];

Answer 2

我发现可以像这样从MyViewController访问对象：

[self setMyObj:[(SampleAppDelegate *)[UIApplication sharedApplication].delegate universalObj]];