Android開發之編寫精美的聊天介面
廢話少說，直接堆程式碼，是看著Android第一行程式碼練習的，大牛繞過，菜鳥勿噴
首先 編寫主介面，修改 activity_main.xml
<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_list_view"
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_text"
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>
然後定義訊息的實體類 Msg.java
package com.example.testdssp;
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;
}
}
編寫子項佈局 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/message_left9"
>
<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/message_left9"
>
<TextView
android:id="@+id/right_msg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_margin="10dp"
android:textColor="#fff"
/>
</LinearLayout>
</LinearLayout>
建立ListView的介面卡類，讓他繼承AraayAdapter，並將泛型指定為Msg
package com.example.testdssp;
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){
//如果收到的訊息，則顯示左邊的訊息佈局，將右邊的訊息佈局隱藏
viewHolder.leftLayout.setVisibility(View.VISIBLE);
viewHolder.rightLayout.setVisibility(View.GONE);
viewHolder.leftMsg.setText(msg.getContent());
}else if(msg.getType()==Msg.TYPE_SENT){
//如果是發出的訊息，則顯示右邊的訊息佈局，將左邊的訊息佈局隱藏
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;
}
}
最後修改主類 ，一些資料的新增，事件的響應
package com.example.testdssp;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
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>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
initMsgs(); //初始化訊息資料
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_SENT);
msgList.add(msg);
adapter.notifyDataSetChanged(); //當有新訊息時，重新整理ListView中的顯示
msgListView.setSelection(msgList.size()); //將ListView定位到最後一行
inputText.setText(""); //清空輸入框的內容
}
}
});
}
@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;
}
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 talking to you",Msg.TYPE_RECEIVED);
msgList.add(msg3);
}
}