ViewModel+LiveData解决Fragment被销毁的问题

app/src/main/java/com/itant/shibei/ui/MainViewModel.java

@@ -7,8 +7,30 @@ import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.ViewModel;
 
 /**
- * 使用ViewModel保存Fragment的数据，阻止Fragment在配合BottomNavigationView切换时总被销毁的问题
+ * 使用ViewModel + LiveData保存Fragment的数据，阻止Fragment在配合BottomNavigationView切换时总被销毁的问题
+ *
  */
+/*public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    mainViewModel=new ViewModelProvider(getActivity()).get(MainViewModel.class);
+    root=mainViewModel.getHomeView().getValue();
+    if(root==null){
+    //正常初始化View
+    root = inflater.inflate(R.layout.fragment_home, container, false);
+    //...
+    }
+    //...
+    return root;
+}*/
+/*@Override
+public void onDestroyView() {
+    super.onDestroyView();
+    //其实以下代码不一定写在onDestroyView()，可以获取指定后root的地方都可以
+    ViewGroup parent = (ViewGroup) root.getParent();
+    if(parent!=null){
+        parent.removeView(root);
+    }
+    mainViewModel.setHomeView(root);
+}*/
 public class MainViewModel extends ViewModel {
     private MutableLiveData<View> mTemplateView;
     private MutableLiveData<View> mHomeView;