无法在私人聊天中显示像消息一样的聊天，并且出现错误

Question

已更新

我正在使用排球库创建一个简单的聊天机器人。我已经在具有3列ID，问题，答案的MySQL数据库中创建了表。相同的PHP代码运行正常，并已通过POSTMAN进行了测试。

我无法并排显示消息。

我尝试创建2 Adapter类，但是它不起作用。我试图通过使用if else将两个适配器文件的代码放入一个。

MainActivity.java

    public class MainActivity extends AppCompatActivity {
    EditText que;
    ImageButton btn;
    ListView messageView;
    ArrayList<Message> arrayList;
    MessageAdapterUser adp;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        que = findViewById(R.id.editText);
        btn = findViewById(R.id.btn);
        messageView = findViewById(R.id.messages_view);
        arrayList = new ArrayList();
        adp = new MessageAdapterUser(MainActivity.this, arrayList);
        messageView.setAdapter(adp);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                arrayList.add(new Message("user",que.getText().toString()));
                adp.notifyDataSetChanged();
                que.getText().clear();
                CallAPiQueAns();
            }
        });
    }
    private void CallAPiQueAns() {
        RequestQueue requestQueue = Volley.newRequestQueue(this);
        StringRequest stringRequest=new StringRequest(Request.Method.POST,
                "http://www.cstech.poornima.org/project/android/que_ans.php",
                new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                try {
//                    Toast.makeText(MainActivity.this, response+"", Toast.LENGTH_SHORT).show();
                    JSONObject jsonObject = new JSONObject(response);
                    if (jsonObject.getString("success").equals("true")){
//                        JSONObject jsonObject1 = jsonObject.getJSONObject("data");
//                        String ans = jsonObject.getString("data");
                        JSONArray jsonArray = jsonObject.getJSONArray("data");
//                        Toast.makeText(MainActivity.this, ans, Toast.LENGTH_SHORT).show();
                        arrayList.add(new Message("bot",jsonArray.getString(0)));
//                        MessageAdapterUser adp = new MessageAdapterUser(MainActivity.this, arrayList);
                        messageView.setAdapter(adp);
//                        adp.notifyDataSetChanged();
                    }
                    else {
                        Toast.makeText(MainActivity.this, "Try Again", Toast.LENGTH_SHORT).show();
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                error.printStackTrace();
                Toast.makeText(MainActivity.this, ""+error, Toast.LENGTH_SHORT).show();
            }
        }){
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String,String> params = new HashMap<>();
                params.put("que",que.getText().toString());
                return params;
            }
        };
        requestQueue.add(stringRequest);
    }
}

MessageAdapterUser.java

    public class MessageAdapterUser extends BaseAdapter {
    List<Message> messages = new ArrayList<Message>();
    Context context;
    LayoutInflater inflater;
    public MessageAdapterUser(Context context, List<Message> messages) {
        this.messages = messages;
        this.context = context;
        inflater = LayoutInflater.from(context);
        notifyDataSetChanged();
    }

    @Override
    public int getCount() {
        return messages.size();
    }

    @Override
    public Object getItem(int position) {
        return messages.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder vh;
//        Toast.makeText(context, messages.get(position).getAns()+"", Toast.LENGTH_SHORT).show();
        if (convertView == null){ // Initially view is empty
            convertView = inflater.inflate(R.layout.message_user, null);
            vh = new ViewHolder(convertView);
            convertView.setTag(vh);
        }else{
            vh = (ViewHolder)convertView.getTag();
        }
        if (messages.get(position).getType().equals("user")) {
            vh.user_message.setText(messages.get(position).getAns());
        }else if (messages.get(position).getType().equals("bot")){
            vh.bot_message.setText(messages.get(position).getAns());
        }
        return convertView;
    }
    class ViewHolder {
        TextView user_message;
        TextView bot_message;
        ViewHolder(View v){
            user_message = (TextView) v.findViewById(R.id.user_message);
            bot_message = (TextView) v.findViewById(R.id.bot_message);
        }
    }
}

Message.java

public class Message {
    private String ans="";
    private String type = "";

    public Message(String type,String ans) {
        this.ans = ans;
        this.type = type;
    }
    public String getType() {return type;}
    public String getAns() {return ans; }
    public void setAns(String ans) { this.ans = ans; }
}

MainActivity.xml

<LinearLayout
    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:orientation="vertical"
    android:clipToPadding="false"
    android:focusableInTouchMode="true"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/messages_view"
        android:layout_width="match_parent"
        android:layout_weight="2"
        android:divider="#fff"
        android:layout_height="wrap_content"
        />

    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#fff"
        android:orientation="horizontal">

        <EditText
            android:id="@+id/editText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="2"
            android:ems="10"
            android:hint="Write a message"
            android:inputType="text"
            android:paddingHorizontal="10dp"
            android:text="" />

        <ImageButton
            android:id="@+id/btn"
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:layout_gravity="center"
            android:scaleType="fitCenter"
            android:layout_marginHorizontal="10dp"
            android:background="@drawable/ic_send_black"
            />
    </LinearLayout>
</LinearLayout>

message_user.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
<RelativeLayout
    android:id="@+id/rl1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingVertical="10dp"
    android:paddingRight="15dp"
    android:paddingLeft="60dp"
    android:clipToPadding="false">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/user_message"
        android:background="@drawable/my_message"
        android:textColor="#fff"
        android:padding="10dp"
        android:elevation="2dp"
        android:textSize="18dp"
        android:layout_alignParentRight="true"
        />

</RelativeLayout>
<RelativeLayout
    android:layout_below="@+id/rl1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingVertical="10dp"
android:paddingLeft="15dp"
android:paddingRight="60dp"
android:clipToPadding="false"
    >

<View
    android:id="@+id/avatar"
    android:layout_alignParentLeft="true"
    android:scaleType="centerInside"
    android:background="@drawable/circle"
    android:layout_width="34dp"
    android:layout_height="34dp" />

<TextView
    android:id="@+id/name"
    android:layout_marginLeft="15dp"
    android:layout_toRightOf="@+id/avatar"
    android:layout_alignTop="@+id/avatar"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingBottom="4dp"
    android:text="Chat Bot"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/bot_message"
    android:layout_below="@+id/name"
    android:layout_alignLeft="@+id/name"
    android:background="@drawable/bot_message"
    android:paddingVertical="12dp"
    android:paddingHorizontal="16dp"
    android:elevation="2dp"
    android:textSize="18dp"
    />
</RelativeLayout>
</RelativeLayout>

查看图片以供参考

https://ibb.co/JBJV5yx

这是屏幕截图。当我输入“你好吗”时，它就会给我输出。

Answer 1

MessageAdapterUser.java中的getView函数将视图返回为null，因为如果消息类型等于'user'，则您将进行两次比较；在第二个中，如果类型是“ bot”，则必须进行比较：

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder vh;
    if (messages.get(position).getType().equals("user")) {
        ...
    }else if (messages.get(position).getType().equals(**"user"**)){ <--- HERE change it to "bot"
       ...
    }
    return convertView;
}