Message2

1.效果图

2.代码

MainActivity

package cn.edu.bzu.message;import java.util.ArrayList;import java.util.List;import android.os.Bundle;import android.app.Activity;import android.view.Menu;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>();@Overrideprotected 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);send = (Button) findViewById(R.id.send);msgListView = (ListView) findViewById(R.id.msg);msgListView.setAdapter(adapter);send.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubString content = inputText.getText().toString();if (!"".equals(content)) {Msg msg = new Msg(content, Msg.TYPE_SENT);msgList.add(msg);adapter.notifyDataSetChanged();msgListView.setSelection(msgList.size());inputText.setText("");}}});}@Overridepublic 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;}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_SENT);msgList.add(msg2);Msg msg3 = new Msg("This is tom.Nice to meet you.", Msg.TYPE_RECEIVED);msgList.add(msg3);}}

Msg

package cn.edu.bzu.message;public class Msg { public static final int TYPE_RECEIVED = 0; public static final int TYPE_SENT = 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; }}

MsgAdapter

 

package cn.edu.bzu.message;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_SENT) {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;}}

activity_main

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="#d8e0e8"    android:orientation="vertical" >    <ListView        android:id="@+id/msg"        android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="1"        android:divider="#0000" >    </ListView>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content" >        <EditText            android:id="@+id/input"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1"            android:hint="Type something here"            android:maxLines="2" />        <Button            android:id="@+id/send"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="Send" />    </LinearLayout></LinearLayout>

msg_item

<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/image" >        <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="215dp"        android:layout_height="wrap_content"        android:layout_gravity="right"        android:background="@drawable/picture" >        <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>