聊天界面

1.运行效果图

2.核心代码

1.activity_main.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:background="#d8e0e8"    android:orientation="vertical"    tools:context="com.example.chatinterface.MainActivity" >    <ListView        android:id="@+id/msg_list_view"        android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="1"        android:divider="#0000" />    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content" >        <EditText            android:id="@+id/input_text"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1"            android:hint="Type something here"            android:maxLines="2" />        <requestFocus />        <Button            android:id="@+id/send"            android:layout_width="wrap_content"            android:layout_height="match_parent"            android:text="send" />    </LinearLayout></LinearLayout>

2.msg_item.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    android:padding="10dp" >    <LinearLayout        android:id="@+id/left_layout"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="left"        android:background="@drawable/left" >        <TextView            android:id="@+id/left_msg"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center"            android:layout_margin="10dp"            android:textColor="#fff" />    </LinearLayout>    <LinearLayout        android:id="@+id/right_layout"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="right"        android:background="@drawable/right" >        <TextView            android:id="@+id/right_msg"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center"            android:layout_margin="10dp" />    </LinearLayout></LinearLayout>

3.MainActivity.java

package com.example.chatinterface;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnClickListener;import android.view.Window;import android.widget.Button;import android.widget.EditText;import android.widget.ListView;public class MainActivity extends Activity {private ListView msgListView;private EditText inputText;private Button send;private MsgAdapter adapter;private List<Msg>msgList=new ArrayList<Msg>();    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        requestWindowFeature(Window.FEATURE_NO_TITLE);        setContentView(R.layout.activity_main);        initMsgs();        adapter=new MsgAdapter(MainActivity.this,R.layout.msg_item,msgList);        inputText=(EditText) findViewById(R.id.input_text);        send=(Button) findViewById(R.id.send);        msgListView=(ListView) findViewById(R.id.msg_list_view);        msgListView.setAdapter(adapter);        send.setOnClickListener(new OnClickListener(){        public void onClick(View v){        String content=inputText.getText().toString();        if(!"".equals(content)){        Msg msg=new Msg(content,Msg.TYPE_SEND);        msgList.add(msg);        adapter.notifyDataSetChanged();        msgListView.setSelection(msgList.size());        inputText.setText("");        }        }        });    }    private void initMsgs(){    Msg msg1=new Msg("Hello guy.",Msg.TYPE_RECEIVED);    msgList.add(msg1);    Msg msg2=new Msg("Hello.Who is that?",Msg.TYPE_SEND);    msgList.add(msg2);    Msg msg3=new Msg("This is Tom.Nice talking to you.",Msg.TYPE_RECEIVED);    msgList.add(msg3);    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.main, menu);        return true;    }    @Override    public boolean onOptionsItemSelected(MenuItem item) {        // Handle action bar item clicks here. The action bar will        // automatically handle clicks on the Home/Up button, so long        // as you specify a parent activity in AndroidManifest.xml.        int id = item.getItemId();        if (id == R.id.action_settings) {            return true;        }        return super.onOptionsItemSelected(item);    }}

4.Msg.java

package com.example.chatinterface;public class Msg {public static final int TYPE_RECEIVED = 0;public static final int TYPE_SEND = 1;private String content;private int type;public Msg(String content, int type) {this.content = content;this.type = type;}public String getContent() {return content;}public int getType() {return type;}}

5.MsgAdapter.java

package com.example.chatinterface;import java.util.List;import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.widget.LinearLayout;import android.widget.TextView;public class MsgAdapter extends ArrayAdapter<Msg>{private int resourceId;public MsgAdapter(Context context,int textViewResourceId,List<Msg>objects){super(context,textViewResourceId,objects);resourceId=textViewResourceId;}public View getView(int position,View convertView,ViewGroup parent){Msg msg=getItem(position);View view;ViewHolder viewHolder;if(convertView==null){view=LayoutInflater.from(getContext()).inflate(resourceId, null);viewHolder=new ViewHolder();viewHolder.leftLayout=(LinearLayout)view.findViewById(R.id.left_layout);viewHolder.rightLayout=(LinearLayout)view.findViewById(R.id.right_layout);viewHolder.leftMsg=(TextView)view.findViewById(R.id.left_msg);viewHolder.rightMsg=(TextView)view.findViewById(R.id.right_msg);view.setTag(viewHolder);}else{view=convertView;viewHolder=(ViewHolder)view.getTag();}if(msg.getType()==Msg.TYPE_RECEIVED){viewHolder.leftLayout.setVisibility(View.VISIBLE);viewHolder.rightLayout.setVisibility(View.GONE);viewHolder.leftMsg.setText(msg.getContent());}else if(msg.getType()==Msg.TYPE_SEND){viewHolder.rightLayout.setVisibility(View.VISIBLE);viewHolder.leftLayout.setVisibility(View.GONE);viewHolder.rightMsg.setText(msg.getContent());}return view;}class ViewHolder{LinearLayout leftLayout;LinearLayout rightLayout;TextView leftMsg;TextView rightMsg;}}

3.运行中出现的问题

对函数调用的不熟悉，使编写程序中出现许多问题。