反应本地异常：指定的孩子已经有父母。

Question

我收到由React Native触发的以下错误。我很确定它与我正在使用的自定义视图相关联。

该视图由一些C++代码（通过OpenGL）生成，该代码被添加到ViewGroup，然后合并到React Native视图中。应用程序第一次加载时，一切都很好。但是，当某些数据发生变化时，似乎React想要重新加载视图，并创建视图的新实例。我正在检查视图是否有父视图，如果是，请在返回视图之前将其删除。但是，在用户选择新数据后，就像视图即将更新一样，发生崩溃。

的ViewManager代码如下：

public class ReactJuceViewManager extends SimpleViewManager<JuceViewHolder> { 

    public static final String REACT_CLASS = "ReactJuceView"; 
    private ReactApplicationContext reactContext; 

    public ReactJuceViewManager(ReactApplicationContext reactContext) 
    { 
     super(); 
     this.reactContext = reactContext; 
    } 

    @Override 
    public String getName() 
    { 
     return REACT_CLASS; 
    } 

    @Override 
    protected JuceViewHolder createViewInstance(ThemedReactContext themedReactContext) { 

     JuceBridge juceBridge = JuceBridge.getInstance(); 
     //JuceBridge manages the a HashMap of `JuceViewHolder`s, never deleting them once created 

     Log.d("ReactJuceViewManager", "createViewInstance"); 
     JuceViewHolder v = juceBridge.getViewForComponent("Tuner", themedReactContext); 

     Log.d("JuceViewHolder", v.getTag().toString()); 
     ViewGroup parent = (ViewGroup) v.getParent(); 
     if (parent != null) 
     { 
      Log.d("ReactJuceViewManager", "JuceViewHolder parent: " + v.getParent().toString()); 
      // Remove from parent 
      Log.i("ReactJuceViewManager", "Removing JuceViewHolder instance from previous parent"); 
      parent.removeView(v); 
     } 
     else 
     { 
      Log.d("ReactJuceViewManager", "JuceViewHolder parent: null"); 
     } 

     return v; 
    } 

} 

..这里是堆栈跟踪：

E/unknown:React: Exception in native call from JS 
                     java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first. 
                      at android.view.ViewGroup.addViewInner(ViewGroup.java:4309) 
                      at android.view.ViewGroup.addView(ViewGroup.java:4145) 
                      at android.view.ViewGroup.addView(ViewGroup.java:4086) 
                      at com.facebook.react.views.view.ReactViewManager.addView(ReactViewManager.java:196) 
                      at com.facebook.react.views.view.ReactViewManager.addView(ReactViewManager.java:39) 
                      at com.facebook.react.uimanager.NativeViewHierarchyManager.manageChildren(NativeViewHierarchyManager.java:384) 
                      at com.facebook.react.uimanager.UIViewOperationQueue$ManageChildrenOperation.execute(UIViewOperationQueue.java:175) 
                      at com.facebook.react.uimanager.UIViewOperationQueue$2.run(UIViewOperationQueue.java:782) 
                      at com.facebook.react.uimanager.UIViewOperationQueue.flushPendingBatches(UIViewOperationQueue.java:829) 
                      at com.facebook.react.uimanager.UIViewOperationQueue.access$1500(UIViewOperationQueue.java:44) 
                      at com.facebook.react.uimanager.UIViewOperationQueue$DispatchUIFrameCallback.doFrameGuarded(UIViewOperationQueue.java:868) 
                      at com.facebook.react.uimanager.GuardedChoreographerFrameCallback.doFrame(GuardedChoreographerFrameCallback.java:32) 
                      at com.facebook.react.uimanager.ReactChoreographer$ReactChoreographerDispatcher.doFrame(ReactChoreographer.java:131) 
                      at android.view.Choreographer$CallbackRecord.run(Choreographer.java:856) 
                      at android.view.Choreographer.doCallbacks(Choreographer.java:670) 
                      at android.view.Choreographer.doFrame(Choreographer.java:603) 
                      at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844) 
                      at android.os.Handler.handleCallback(Handler.java:739) 
                      at android.os.Handler.dispatchMessage(Handler.java:95) 
                      at android.os.Looper.loop(Looper.java:148) 
                      at android.app.ActivityThread.main(ActivityThread.java:5417) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 

Answer 1

我改怎么组件的JuceBridge商店引用 - 存储ComponentPeerView！而非将View即JuceViewHolder。

（见我fork of JUCE）

然后我访问的ComponentPeerView的父母这解决了我的问题：

protected ReactJuceView createViewInstance(ThemedReactContext themedReactContext) { 
    JuceBridge juceBridge = JuceBridge.getInstance(); 
    juceBridge.setActivityContext(themedReactContext); 

    ReactJuceView v = new ReactJuceView(themedReactContext); 

    JuceBridge.ComponentPeerView componentPeerView = juceBridge.getPeerViewForComponent("MainComponent"); 
    if (componentPeerView != null) { 

     Log.d ("ReactJuceViewManager", "Got componentPeerView"); 
     ViewGroup parent = (ViewGroup) componentPeerView.getParent(); 
     if (parent != null) { 

      parent.removeView(componentPeerView); 
     } 
     v.addView(componentPeerView); 
     Log.d("ReactJuceViewManager", "About to attachOpenGlContext"); 
     MainActivity.attachOpenGLContext("MainComponent"); 
    } 
    else 
     Log.d("ReactJuceViewManager", "componentPeerView is null"); 

    return v; 
}