QQl聊天消息

Activity：

 package com.zzw.qqchat;

 import java.util.ArrayList;
 import java.util.HashMap;

 import android.app.Activity;
 import android.content.Context;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.widget.ArrayAdapter;
 import android.widget.EditText;
 import android.widget.ListView;
 import android.widget.TextView;

 public class MainActivity extends Activity {
     private final int VIEW_TYPE = 0x001;
     private final int MESSAGE = 0x002;

     private final int VIEW_TYPE_LEFT = -1;
     private final int VIEW_TYPE_RIGHT = -2;

     private ArrayList<HashMap<Integer, Object>> items;
     private MyAdapter adapter;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);

         final ListView listView = (ListView) findViewById(R.id.list);

         items = new ArrayList<HashMap<Integer, Object>>();

         addData();

         adapter = new MyAdapter(this, -1);
         listView.setAdapter(adapter);

         final EditText et = (EditText) findViewById(R.id.msgEditText);

         findViewById(R.id.msgSend).setOnClickListener(new OnClickListener() {

             @Override
             public void onClick(View v) {
                 String msg = et.getText() + "";

                 HashMap<Integer, Object> map = new HashMap<Integer, Object>();
                 map.put(VIEW_TYPE, VIEW_TYPE_RIGHT);
                 map.put(MESSAGE, msg);
                 items.add(map);
                 // item数据变化时通知adapter刷新及时改变view
                 adapter.notifyDataSetChanged();
                 // 刷新后清空输入框
                 et.setText("");
                 // 输入框发送消息后将ListView滚动到底部
                 listView.setSelection(ListView.FOCUS_DOWN);

             }
         });
     }

     private void addData() {
         for (int i = 0; i < 10; i++) {
             if (i % 2 == 0) {
                 HashMap<Integer, Object> map = new HashMap<Integer, Object>();
                 map.put(VIEW_TYPE, VIEW_TYPE_LEFT);
                 map.put(MESSAGE, "对方说的消息:" + i);
                 items.add(map);
             } else {
                 HashMap<Integer, Object> map = new HashMap<Integer, Object>();
                 map.put(VIEW_TYPE, VIEW_TYPE_RIGHT);
                 map.put(MESSAGE, "我说的消息:" + i);
                 items.add(map);
             }
         }
     }

     private class MyAdapter extends ArrayAdapter {
         private LayoutInflater inflater;

         public MyAdapter(Context context, int resource) {
             super(context, resource);
             inflater = LayoutInflater.from(context);
         }

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

         @Override
         public String getItem(int position) {

             String message = items.get(position).get(MESSAGE) + "";
             return message;
         }

         @Override
         public View getView(int position, View convertView, ViewGroup parent) {

             int type = getItemViewType(position);
             String message = getItem(position);

             switch (type) {
             case VIEW_TYPE_LEFT:
                 if (convertView == null) {
                     convertView = inflater.inflate(R.layout.left, null);
                 }
                 TextView textViewLeft = (TextView) convertView.findViewById(R.id.textView);
                 textViewLeft.setText(message);
                 break;

             case VIEW_TYPE_RIGHT:
                 if (convertView == null) {
                     convertView = inflater.inflate(R.layout.right, null);
                 }
                 TextView textViewRight = (TextView) convertView.findViewById(R.id.textView);
                 textViewRight.setText(message);
                 break;
             }

             return convertView;
         }

         @Override
         public int getItemViewType(int position) {
             HashMap map = items.get(position);
             int type = (Integer) map.get(VIEW_TYPE);
             return type;
         }

         @Override
         public int getViewTypeCount() {
             return 2;
         }
     }
 }

activity_main.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="match_parent" >

     <ListView
         android:id="@+id/list"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_above="@+id/commentLinearLayout"
         android:layout_alignParentTop="true"
         android:divider="@android:color/transparent"
         android:dividerHeight="15dip"
         android:scrollbars="none" />

     <LinearLayout
         android:id="@+id/commentLinearLayout"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_alignParentBottom="true"
         android:background="#e0e0e0"
         android:orientation="horizontal" >

         <EditText
             android:id="@+id/msgEditText"
             android:layout_width="0dip"
             android:layout_height="wrap_content"
             android:layout_weight="8"
             android:hint="发送消息" />

         <Button
             android:id="@+id/msgSend"
             style="?android:attr/buttonStyleSmall"
             android:layout_width="0dip"
             android:layout_height="wrap_content"
             android:layout_weight="2"
             android:text="发送" />
     </LinearLayout>

 </RelativeLayout>

activity_main

left.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="match_parent"
     android:orientation="horizontal" >

     <ImageView
         android:id="@+id/imageView"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentLeft="true"
         android:layout_centerVertical="true"
         android:singleLine="false"
         android:src="@drawable/ic_launcher" />

     <TextView
         android:id="@+id/textView"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_centerVertical="true"
         android:layout_toRightOf="@+id/imageView"
         android:background="#ff5252"
         android:text="left" />

 </RelativeLayout>

left

 <?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="match_parent"
     android:orientation="horizontal" >

     <ImageView
         android:id="@+id/imageView"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentRight="true"
         android:layout_centerVertical="true"
         android:src="@drawable/ic_launcher" />

     <TextView
         android:id="@+id/textView"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_centerVertical="true"
         android:layout_toLeftOf="@+id/imageView"
         android:background="#2196f3"
         android:singleLine="false"
         android:text="right" />

 </RelativeLayout>

right