在聊天應用程序的回收站內切換佈局

-1

嗨，我正在開發一個聊天應用程序。我有兩個類別運營商和訪問者。取決於此類別，並像在典型的聊天應用程序中一樣在左側或右側顯示消息。在聊天應用程序的回收站內切換佈局

有人能幫助我實現這一點。

我試過了，但得到一個錯誤。

FATAL EXCEPTION: main 
Process: zupportdesk.desk.zupport.chatsystem, PID: 31103 
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference 
at zupportdesk.desk.zupport.chatsystem.Data.ChattingAdapter.onBindViewHolder(ChattingAdapter.java:66) 
at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:5822) 
at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:5855) 
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5091) 
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4967) 
at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2029) 
at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1414) 
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1377) 
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:578) 
at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3315) 
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3124) 
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3568) 
at android.view.View.layout(View.java:16636) 
at android.view.ViewGroup.layout(ViewGroup.java:5437) 
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1079) 
at android.view.View.layout(View.java:16636) 
at android.view.ViewGroup.layout(ViewGroup.java:5437) 
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336) 
at android.widget.FrameLayout.onLayout(FrameLayout.java:273) 
at android.view.View.layout(View.java:16636) 
at android.view.ViewGroup.layout(ViewGroup.java:5437) 
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1735) 
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1579) 
at android.widget.LinearLayout.onLayout(LinearLayout.java:1488) 
at android.view.View.layout(View.java:16636) 
at android.view.ViewGroup.layout(ViewGroup.java:5437) 
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336) 
at android.widget.FrameLayout.onLayout(FrameLayout.java:273) 
at android.view.View.layout(View.java:16636) 
at android.view.ViewGroup.layout(ViewGroup.java:5437) 
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1735) 
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1579) 
at android.widget.LinearLayout.onLayout(LinearLayout.java:1488) 
at android.view.View.layout(View.java:16636) 
at android.view.ViewGroup.layout(ViewGroup.java:5437) 
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336) 
at android.widget.FrameLayout.onLayout(FrameLayout.java:273) 
at com.android.internal.policy.PhoneWindow$DecorView.onLayout(PhoneWindow.java:2678) 
at android.view.View.layout(View.java:16636) 
at android.view.ViewGroup.layout(ViewGroup.java:5437) 
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2179) 
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1939) 
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1115) 
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6023) 
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858) 
at android.view.Choreographer.doCallbacks(Choreographer.java:670) 
at android.view.Choreographer.doFrame(Choreographer.java:606) 
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844) 
at android.os.Handler.handleCallback(Handler.java:739) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5422) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

電流誤差是這裏

if(message_type.equals("Operator")) { 
      ((ViewHolder) holder).visitorMessage.setText(message.getMessage()); 
      ((ViewHolder) holder).visitortime.setText(message.getDateTime()); 
     } else { 
      ((ViewHolder) holder).operatorMessage.setText(message.getDateTime()); 
      ((ViewHolder) holder).operatorTime.setText(message.getDateTime()); 
     }

適配器

public class ChattingAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{ 

    public List<ChattingItomObject> ChattingItem; 
    private Context context; 

    public ChattingAdapter(Context context, List<ChattingItomObject> items){ 
     this.ChattingItem = items; 
     this.context = context; 
    } 

    public class ViewHolder extends RecyclerView.ViewHolder { 
     public TextView operatorMessage; 
     public TextView operatorTime; 
     public TextView visitorMessage; 
     public TextView visitortime; 

     public ViewHolder(View view) { 
      super(view); 
      operatorMessage = (TextView) view.findViewById(R.id.CCO_message); 
      operatorTime = (TextView) view.findViewById(R.id.CCo_time); 

      visitorMessage = (TextView) view.findViewById(R.id.CCV_message); 
      visitortime = (TextView) view.findViewById(R.id.CCV_time); 
     } 
    } 

    @Override 
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
     View itemView; 

     if (viewType == 5001) { 
      // self message 
      itemView = LayoutInflater.from(parent.getContext()) 
        .inflate(R.layout.custom_chat_operator, parent, false); 
     } else if(viewType == 5002) { 
      // others message 
      itemView = LayoutInflater.from(parent.getContext()) 
        .inflate(R.layout.custom_chat_visitor, parent, false); 
     }else { 
      itemView = LayoutInflater.from(parent.getContext()) 
        .inflate(R.layout.custom_chat_other, parent, false); 
     } 
     return new ViewHolder(itemView); 
    } 

    @Override 
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { 
     ChattingItomObject message = ChattingItem.get(position); 
     String message_type = message.getMessageType().toString(); 

     if(message_type.equals("Operator")) { 
      ((ViewHolder) holder).visitorMessage.setText(message.getMessage()); 
      ((ViewHolder) holder).visitortime.setText(message.getDateTime()); 
     } else { 
      ((ViewHolder) holder).operatorMessage.setText(message.getDateTime()); 
      ((ViewHolder) holder).operatorTime.setText(message.getDateTime()); 
     } 
    } 

    @Override 
    public int getItemViewType(int position) { 
     String message = ChattingItem.get(position).getMessageType(); 
     if (message.equals("Operator")) { 
      return 5001; 
     } else if(message.equals("Visitor")){ 
      return 5002; 
     } 

     return position; 
    } 

    @Override 
    public int getItemCount() { return ChattingItem.size(); } 
}

聊天活動

public class Chatting extends AppCompatActivity { 

    private String uniqueID; 
    public ChattingAdapter mAdapter; 
    public List<ChattingItomObject> messageItems; 
    private RecyclerView recyclerView; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_chatting); 


     uniqueID = UUID.randomUUID().toString(); 
     Log.d("GUIID", uniqueID); 

     messageItems = new ArrayList<ChattingItomObject>(); 
     // add some items to list to test 
     messageItems.add(new ChattingItomObject("VisitorID", "Message", "10:30 pm", "OperatorType", "UserName", "Operator", uniqueID)); 
     messageItems.add(new ChattingItomObject("VisitorID", "Message", "10:30 pm", "OperatorType", "UserName", "Visitor", uniqueID)); 
     messageItems.add(new ChattingItomObject("VisitorID", "Message", "10:30 pm", "OperatorType", "UserName", "Operator", uniqueID)); 
     messageItems.add(new ChattingItomObject("VisitorID", "Message", "10:30 pm", "OperatorType", "UserName", "Visitor", uniqueID)); 
     messageItems.add(new ChattingItomObject("VisitorID", "Message", "10:30 pm", "OperatorType", "UserName", "Operator", uniqueID)); 
     messageItems.add(new ChattingItomObject("VisitorID", "Message", "10:30 pm", "OperatorType", "UserName", "Operator", uniqueID)); 
     messageItems.add(new ChattingItomObject("VisitorID", "Message", "10:30 pm", "OperatorType", "UserName", "Visitor", uniqueID)); 



     recyclerView = (RecyclerView) findViewById(R.id.recycler_chat); 
     mAdapter = new ChattingAdapter(this, messageItems); 

     LinearLayoutManager layoutManager = new LinearLayoutManager(this); 
     recyclerView.setLayoutManager(layoutManager); 
     recyclerView.setItemAnimator(new DefaultItemAnimator()); 
     recyclerView.setAdapter(mAdapter); 

    } 

}

activity_chatting.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    tools:context="zupportdesk.desk.zupport.chatsystem.Chatting"> 

    <android.support.v7.widget.RecyclerView 
     android:id="@+id/recycler_chat" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:layout_alignParentTop="true" 
     android:layout_centerHorizontal="true" 
     android:scrollbars="none" /> 


    <EditText 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_weight="1" 
     android:textColorHint="#CFD8DC" 
     android:textColor="#CFD8DC" 
     android:hint="Write a message" 
     android:id="@+id/editText" 
     android:layout_alignParentBottom="true" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentStart="true" 
     android:layout_toLeftOf="@+id/imageView5" 
     android:layout_toStartOf="@+id/imageView5" /> 

    <ImageView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_weight="5" 
     android:padding="4dp" 
     android:src="@android:drawable/ic_menu_send" 
     android:id="@+id/imageView5" 
     android:layout_alignBottom="@+id/editText" 
     android:layout_alignParentRight="true" 
     android:layout_alignParentEnd="true" /> 
</RelativeLayout>

custom_chat_visitor.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" android:layout_width="match_parent" 
    android:layout_height="match_parent"> 


    <ImageView 
     android:id="@+id/imageView4" 
     android:layout_width="30dp" 
     android:layout_height="30dp" 
     android:layout_weight="1" 
     android:src="@drawable/arrow_bg2" 
     android:layout_above="@+id/CCV_time" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentStart="true" /> 

    <TextView 
     android:id="@+id/CCV_message" 
     android:layout_width="300dp" 
     android:layout_height="wrap_content" 
     android:layout_weight="6" 
     android:background="@drawable/chat_visitor" 
     android:padding="16dp" 
     android:text="Android charting application xml ui design. " 
     android:textColor="#000" 
     android:layout_alignParentTop="true" 
     android:layout_toRightOf="@+id/imageView4" 
     android:layout_toEndOf="@+id/imageView4" 
     android:layout_marginTop="5dp" /> 

    <TextView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="New Text" 
     android:id="@+id/CCV_time" 
     android:textSize="8dp" 
     android:layout_alignBottom="@+id/CCV_message" 
     android:layout_toRightOf="@+id/imageView4" 
     android:layout_toEndOf="@+id/imageView4" 
     android:layout_marginLeft="16dp" 
     android:layout_marginStart="16dp" 
     android:layout_marginBottom="2dp" /> 

</RelativeLayout>

custom_chat_operator.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" android:layout_width="match_parent" 
    android:layout_height="match_parent"> 


    <TextView 
     android:id="@+id/CCO_message" 
     android:layout_width="300dp" 
     android:layout_height="wrap_content" 
     android:layout_weight="6" 
     android:background="@drawable/chat_operator" 
     android:padding="16dp" 
     android:text=" AndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAndAnd" 
     android:textColor="#000" 
     android:layout_alignParentTop="true" 
     android:layout_alignRight="@+id/imageView3" 
     android:layout_alignEnd="@+id/imageView3" 
     android:layout_marginRight="20dp" 
     android:layout_marginEnd="15dp" 
     android:layout_marginTop="5dp" /> 

    <ImageView 
     android:id="@+id/imageView3" 
     android:layout_width="30dp" 
     android:layout_height="30dp" 
     android:layout_weight="1" 
     android:src="@drawable/arrow_bg1" 
     android:layout_alignBottom="@+id/CCO_message" 
     android:layout_alignParentRight="true" 
     android:layout_alignParentEnd="true" 
     android:layout_marginBottom="15dp" /> 

    <TextView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="10:30 PM" 
     android:id="@+id/CCo_time" 
     android:textSize="8dp" 
     android:layout_alignBottom="@+id/CCO_message" 
     android:layout_toLeftOf="@+id/imageView3" 
     android:layout_toStartOf="@+id/imageView3" 
     android:layout_marginBottom="2dp" /> 

</RelativeLayout>

來源

2016-09-08 Sathya Baman

根據作爲操作員或訪問者的消息類型，您一次只分配一個佈局，但之後您將訪問這兩個佈局的textview，因此出現問題，您只需檢查一個佈局，它的屬性 – Vickyexpert

您是否嘗試過'equalsIgnoreCase （「」）'意思就像'if（message_type.equalsIgnoreCase（「Operator」））'？如果沒有，那麼嘗試一次。 –

您需要創建兩個不同由於視圖回收viewholder爲每個佈局

private final int Operator = 0, Visitor = 1; 
    @Override 
     public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) { 
      switch (viewHolder.getItemViewType()) { 
       case Operator: 
        ViewHolder1 vh1 = (ViewHolder1) viewHolder; 
        configureViewHolder1(vh1, position); 
        break; 
       case Visitor: 
        ViewHolder2 vh2 = (ViewHolder2) viewHolder; 
        configureViewHolder2(vh2, position); 
        break; 

      } 
     } 



    private void configureViewHolder1(ViewHolder1 vh1, int position) { 
      vh1.visitorMessage.setText(message.getMessage()); 
      vh1.visitortime.setText(message.getDateTime()); 
     } 

     private void configureViewHolder2(ViewHolder2 vh2,int position) { 
      vh2.operatorMessage.setText(message.getDateTime()); 
      vh2.operatorTime.setText(message.getDateTime()); 
     } 

    @Override 
     public int getItemViewType(int position) { 
String message_type = message.getMessageType().toString(); 

     if(message_type.equals("Operator")) 
      { 
       return Operator; 
      } else { 
       return Visitor; 
      } 
      return -1; 
     }

來源

2016-09-08 05:29:49 Krutik

可以確認此方法有效。我在這個週末才使用它。 – Zach

他得到一個空指針異常... – Chisko

你得到空指針，你必須區分使用getItemViewType這樣的觀點：

// 5002 is for visitors 
    if(getItemViewType(position)==5002) { 
       ((ViewHolder) holder).visitorMessage.setText(message.getMessage()); 
       ((ViewHolder) holder).visitortime.setText(message.getDateTime()); 
      } else { 
       ((ViewHolder) holder).operatorMessage.setText(message.getDateTime()); 
       ((ViewHolder) holder).operatorTime.setText(message.getDateTime()); 
      }

來源

2016-09-08 06:22:42

if(getItemViewType != null){ 
if(getItemViewType(position)==5002) { 
       ((ViewHolder) holder).visitorMessage.setText(message.getMessage()); 
       ((ViewHolder) holder).visitortime.setText(message.getDateTime()); 
      } else { 
       ((ViewHolder) holder).operatorMessage.setText(message.getDateTime()); 
       ((ViewHolder) holder).operatorTime.setText(message.getDateTime()); 
      }}

，但我不認爲我們的代碼是不工作，嘗試清理項目

來源

2016-09-08 06:35:21 Rodriquez

我認爲問題是這樣的，當消息類型爲Operator時，您設置訪客佈局和ViceVersa的文本，該文本在該po上沒有膨脹所以android studio會返回給你一個nullPointerException。

if(message_type.equals("Operator")) { 
     ((ViewHolder) holder).visitorMessage.setText(message.getMessage()); 
     ((ViewHolder) holder).visitortime.setText(message.getDateTime()); 
    } else { 
     ((ViewHolder) holder).operatorMessage.setText(message.getDateTime()); 
     ((ViewHolder) holder).operatorTime.setText(message.getDateTime()); 
    }

還您oncreateViewHolder你定義3種可能的佈局，是經營商，遊客和其他...佈局。嘗試在你的getItemViewType（）方法上使用3個標識返回值，例如5001,5002,5003以識別每個充氣佈局。

來源

2016-09-08 06:56:36 pastillas

在聊天應用程序的回收站內切換佈局

回答

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