在React Native中使用nativeID /与RCTRootView子视图一起使用的正确方法是什么？

Question

I have an existing iOS app and I am using react native's RCTRootView to draw some components for my app.

// swift
private lazy var RNContent: RCTRootView = {
    let mockData:NSDictionary = ["someProps": self.someProps]
    let RNContent = RCTRootView(bridge: self.bridge, moduleName: "RNContent", initialProperties: mockData as [NSObject : AnyObject])!
    return RNContent
  }()

// JS
AppRegistry.registerComponent('RNContent', () => component);

---

Here is what my RN hierarchy looks like

<View>
  <View>
   <Text />
   <ScrollView /> <--
  <View>
</View>

I want to get a hold of this ScrollView on the native side. As per the docs nativeID should help. However, I can't see any subviews inside the RCTRootView that I define in JS side. In fact, root view only has a single subview called RCTRootContentView which does not have any further subviews available.

So my question is what is the correct way to get hold of the subviews of RCRootView on the native side?

I have tried a few things like, using the UIManager 's addUIBlock to get hold of the view register, but I think there is an obvious point I am missing related to the RCTRootView and how it works.

Interestingly, if I directly use a natively registered component (registered via RCT_EXTERN_MODULE ) in my RN hierarchy I can see that this component is detached from the RCTRootContentView and it also has a nativeID that I assigned to it on the JS side.

 RCTExecuteOnUIManagerQueue {
      self.bridge.uiManager.addUIBlock { (uiManager: RCTUIManager?, viewRegistry:[NSNumber : UIView]?) in

        uiManager?.view(forNativeID: "SelfAssignedID", withRootTag: self. RNContent.reactTag) // nil

        viewRegistry?.forEach({ (key: NSNumber, value: UIView) in
          print("Test1: ", key, value.nativeID) // only native components has nativeID, which does makes sense because RCTRootContentView doesn't have subviews... but why not? is there a way to get hold of them? If not, why not?
        })
      }
    }

---

Any help would be helpful, thanks!

Answer 1

In fact, root view only has a single subview called RCTRootContentView which does not have any further subviews available.

This seems like an issue to me. The <Text/> node in JS should be creating a UITextView child in the native content view. Maybe try actually adding some content to <Text/> and <ScrollView/> to get it to render?

I want to get a hold of this ScrollView on the native side.

Can you give some more context on what you're trying to do? I have a feeling nativeID API isn't what you want to use.