Schaltplan innerhalb der Recyclerview für Chat-Anwendung

Question

Hallo ich entwickle eine Chat-Anwendung. Ich habe zwei Kategorien Operator und Visitor. abhängig von dieser Kategorie und zeigen die Nachrichten auf der linken oder rechten Seite wie in einer typischen Chat-Anwendung.

Kann mir jemand helfen, dies zu erreichen.

Ich versuchte, aber einen Fehler zu bekommen.

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) 

aktuellen Fehler ist hier

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()); 
     } 

Adapter

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(); } 
} 

Chat Aktivität

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> 

Answer 1

Sie erstellen müssen zwei verschiedene viewholder für jedes Layout

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; 
     } 

Answer 2

Sie Null-Zeiger immer aufgrund Recycling Sicht haben Sie Ansichten zu unterscheiden getItemViewType wie folgt aus:

// 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()); 
      } 

Answer 3

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()); 
      }} 

, aber ich glaube nicht, dass ur-Code funktioniert nicht, versuchen, ein Projekt zu reinigen

Answer 4

Ich denke, das Problem ist dies, wenn der Nachrichtentyp Operator ist, legen Sie den Text eines Besucherlayouts und ViceVersa, die nicht auf diese po aufgeblasen ist so wird android studio Ihnen eine nullPointerException zurückgeben.

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()); 
    } 

auch auf Ihrem oncreateViewHolder Sie definieren 3 mögliche Layout, das Operater, Besucher und andere ... Layout sind. Versuchen Sie, 3 Identifikations-Rückgabewert auf Ihrem getItemViewType() z. 5001, 5002, 5003, um jedes der aufgeblähten Layouts zu identifizieren.