當刪除數據時，FirebaseRecyclerAdapter不更新項目索引

我有一個項目列表，每個項目都有一個名稱和一個刪除按鈕。當刪除數據時，FirebaseRecyclerAdapter不更新項目索引

我populateViewHolder方法

@Override 
    protected void populateViewHolder(SubChannelViewHolder viewHolder, final SubChannel model, final int position) { 

    //passing a clickListener to viewHolder,viewHolder in turn decides to which view it should assign this clickListener. 
    viewHolder.bindToSubChannel(model, new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
     String key= getRef(position).getKey();//Getting the key of the subChannel item 

     Map<String,Object> childUpdates=new HashMap<>(); 

     //The positions where the subChannel was stored 
     childUpdates.put("/channels-subChannels/"+mChannelKey+"/" +key+"/subChannelName/",null); 
     childUpdates.put("/channels/" + mChannelKey+"/subChannels/"+key+"/subChannelName/", null); 
     childUpdates.put("/user-channels/" +getUid()+"/"+ mChannelKey+"/subChannels/"+key+"/subChannelName/", null); 

     //setting values at these location as null thereby doing batch deleting. 
     mDatabase.updateChildren(childUpdates); 
    } 
    }); 
}

我ViewHolder：我ViewHolder裏面我有一個bindToSubChannel方法，這需要通過&設置上刪除的ImageView的clickListener的FirebaseRecyclerAdapter檢索的對象。

public class SubChannelViewHolder extends RecyclerView.ViewHolder { 

    private TextView subChannelNameTextView; 
    private ImageView removeImageView; 

    public SubChannelViewHolder(View itemView) { 
    super(itemView); 
    subChannelNameTextView=(TextView)itemView.findViewById(R.id.subChannel_name_text_view); 
    removeImageView =(ImageView)itemView.findViewById(R.id.remove_image_view); 
    } 
    public void bindToSubChannel(SubChannel subChannel,View.OnClickListener RemoveImageClickListener){ 
    subChannelNameTextView.setText(subChannel.getSubChannelName()); 
    removeImageView.setOnClickListener(RemoveImageClickListener); 
    } 
}

我會在這條線以下IndexOutOfBoundsException異常：

String key= getRef(position).getKey();

時說，我曾在列表6項拋出異常（1,2,3,4,5,6 ）&我刪除了1,2。

後來，當我按下刪除6適配器檢索第6項指標是原來的6但卻適配器的大小發生了變化，以4

E/AndroidRuntime: FATAL EXCEPTION: main 
Process: in.arnavvohra.arry2, PID: 1493 
java.lang.IndexOutOfBoundsException: Invalid index 2, size is 2 
at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255) 
at java.util.ArrayList.get(ArrayList.java:308) 
at com.firebase.ui.database.FirebaseArray.getItem(FirebaseArray.java:52) 
at com.firebase.ui.database.FirebaseRecyclerAdapter.getRef(FirebaseRecyclerAdapter.java:150) 
at in.arnavvohra.arry2.EditSubChannelsActivity$2$1.onClick(EditSubChannelsActivity.java:67) 
at android.view.View.performClick(View.java:5076) 
at android.view.View$PerformClick.run(View.java:20279) 
at android.os.Handler.handleCallback(Handler.java:739) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5930) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)

如何（1,2刪除後）我應該着手解決這個問題嗎？

來源

2016-07-24 Arnav Vohra

你不應該叫'notifyItemRemoved（）'或適配器上的相似。只需從數據庫中刪除項目，剩下的就會自動發生。 –

最初我已經刪除它們，但搜索所以我發現它們應該被添加。無論如何，我的錯誤仍然存在，即使我刪除它們。 –

@FrankvanPuffelen你或你的團隊中的某人可以幫忙嗎？ –

而不是考慮position綁定ViewHolder時是最終的，而不是創建一個最終的參考項：

@Override 
    protected void populateViewHolder(SubChannelViewHolder viewHolder, final SubChannel model, int position) { 

    // Move this out here, mark it as final. Then reference it inside the block. 
    final String Key = getRef(position).getKey(); 

    //passing a clickListener to viewHolder,viewHolder in turn decides to which view it should assign this clickListener. 
    viewHolder.bindToSubChannel(model, new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
     Map<String,Object> childUpdates=new HashMap<>(); 

     //The positions where the subChannel was stored 
     childUpdates.put("/channels-subChannels/"+mChannelKey+"/" +key+"/subChannelName/",null); 
     childUpdates.put("/channels/" + mChannelKey+"/subChannels/"+key+"/subChannelName/", null); 
     childUpdates.put("/user-channels/" +getUid()+"/"+ mChannelKey+"/subChannels/"+key+"/subChannelName/", null); 

     //setting values at these location as null thereby doing batch deleting. 
     mDatabase.updateChildren(childUpdates); 
    } 
    }); 
}

來源

2016-07-25 23:29:04

當刪除數據時，FirebaseRecyclerAdapter不更新項目索引

回答

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