Android_2.2_eclips_ToDoList

任务添加程序，输入信息点击方向键中介的键添加。KEYCODE_DPAD_CENTER

（涉及内容，adapter简单应用，简单布局。）

mainActivity

package com.gongsi.todolist;

import java.util.ArrayList;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
/*
 * adapter增加list条目的demo
 */
public class ToDoListActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        ListView myListView = (ListView)findViewById(R.id.myListView);
        final EditText myEditText = (EditText)findViewById(R.id.myEditText);
        
        final ArrayList<String> todoItems = new ArrayList<String>();
        final ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1,
                todoItems);
        myListView.setAdapter(adapter);
        
        myEditText.setOnKeyListener(new View.OnKeyListener() {
            
            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                if(event.getAction() == KeyEvent.ACTION_DOWN){
                    /*手机上下左右键的中间确定键 KEYCODE_DPAD_CENTER*/
                    if(keyCode == KeyEvent.KEYCODE_DPAD_CENTER){
                        todoItems.add(0, myEditText.getText().toString());
                        adapter.notifyDataSetChanged();//通知adapter更新
                        myEditText.setText("");
                        return true;
                    }
                }
                return false;
            }
        });
    }
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<EditText 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:id="@+id/myEditText"
    android:text="New To Do List"
    />
<ListView 
    android:id="@+id/myListView"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
/>
</LinearLayout>