1.首先编写main.xml文件：
<?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="45dp"
android:layout_gravity="left"
android:background="@drawable/message_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="45dp"
android:layout_gravity="right"
android:background="@drawable/message_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>
2.然后来定义一个消息实体类Msg:
package org.lxh.demo;
public class Msg {
public static final int TYPE_RECEIVED = 1;
public static final int TYPE_SENT = 0;
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;
}
}
3.新建msg_item.xml代码：
<?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="45dp"
android:layout_gravity="left"
android:background="@drawable/message_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="45dp"
android:layout_gravity="right"
android:background="@drawable/message_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>
4.新建MsgAdapter继承自ArrayAdapter:
package org.lxh.demo;
import java.util.List;
import android.R.integer;
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;
}
@Override
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) {// 判断消息类型，决定哪边显示
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;
}
}
5.MainActivity:
package org.lxh.demo;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnFocusChangeListener;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
public class Hello extends Activity {
private ListView msgListView;
private EditText inputText;
private Button send;
private MsgAdapter adapter;
private List<Msg> msgList=new ArrayList<Msg>();
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState); // 生命周期方法
requestWindowFeature(Window.FEATURE_NO_TITLE);
super.setContentView(R.layout.main); // 设置要使用的布局管理器
initMsg();
adapter=new MsgAdapter(Hello.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_SENT);
msgList.add(msg);
adapter.notifyDataSetChanged();//当有县消息时刷新ListView中的显示
msgListView.setSelection(msgList.size());//将ListView定位到最后一行
inputText.setText("");
}
}
});
}
private void initMsg() {
Msg msg1=new Msg("Hi Peter", Msg.TYPE_RECEIVED);
msgList.add(msg1);
Msg msg2=new Msg("Hello Dog", Msg.TYPE_SENT);
msgList.add(msg2);
Msg msg3=new Msg("How are you?", Msg.TYPE_RECEIVED);
msgList.add(msg3);
}
}
运行实例如下：
源码下载地址：http://download.csdn.net/detail/yayun0516/8736781
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时间： 2024-11-05 16:23:33