Android 自定义Adapter以实现自定义填充ListView的Item

1>实体类－－－即ListView中各个Item中填充的内容

package com.demo.cxc.compoundview.com.demo.cxc.entity;

import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * Created by CXC on 15/4/14.
 */
public class ToDoItem {
    private String task;
    private Date createdDate;
    //构造函数
    public ToDoItem(String task){
        this(task,new Date(java.lang.System.currentTimeMillis()));
    }
    public ToDoItem(String task,Date createdDate){
        this.task=task;
        this.createdDate=createdDate;
    }

    //getters && setters


    public String getTask() {
        return task;
    }

    public void setTask(String task) {
        this.task = task;
    }

    public Date getCreatedDate() {
        return createdDate;
    }

    public void setCreatedDate(Date createdDate) {
        this.createdDate = createdDate;
    }

    @Override
    public String toString() {
        SimpleDateFormat sdf=new SimpleDateFormat("dd/MM/yy");
        String dateString =sdf.format(this.createdDate);
        return "("+dateString+") "+this.task;
    }
}

2>自定义Adapter类

package com.demo.cxc.compoundview.com.demo.cxc.adapter;

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;

import com.demo.cxc.compoundview.R;
import com.demo.cxc.compoundview.com.demo.cxc.entity.ToDoItem;

import org.w3c.dom.Text;

import java.text.SimpleDateFormat;
import java.util.List;

/**
 * Created by CXC on 15/4/14.
 */
public class ToDoItemAdapter extends ArrayAdapter<ToDoItem> {
    private int resource_id;

    public ToDoItemAdapter(Context context, int resource_id, List<ToDoItem> items) {
        super(context, resource_id, items);
        this.resource_id = resource_id;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        LinearLayout todoView;

        ToDoItem toDoItem=getItem(position);
        if(convertView==null){//不是一次更新，则填充一个新视图

            todoView=new LinearLayout(getContext());
            LayoutInflater layoutInflater=(LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            layoutInflater.inflate(resource_id,todoView,true);

        }else {//否则更新该视图

            todoView=(LinearLayout)convertView;
        }
        //得到对象的各个属性值
        TextView task_tv=(TextView)todoView.findViewById(R.id.task_tv);
        TextView date_tv=(TextView)todoView.findViewById(R.id.date_tv);

        //填充该Item 中各个View的内容
        task_tv.setText(toDoItem.getTask());
        date_tv.setText(new SimpleDateFormat("dd/MM/yy").format(toDoItem.getCreatedDate()));

        return todoView;
    }
}

3>MainActivity

3.1>布局

<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:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">


    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <EditText
            android:id="@+id/new_item_et"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:hint="Please input what to do ..."
            android:layout_weight="1"/>
        <Button
            android:id="@+id/commit_bt"
            android:text="Ok"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />
    </LinearLayout>

    <ListView
        android:id="@+id/todo_list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"></ListView>


</LinearLayout>

效果如图所示

3.2>代码如下

package com.demo.cxc.compoundview;

import android.content.DialogInterface;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;

import com.demo.cxc.compoundview.com.demo.cxc.adapter.ToDoItemAdapter;
import com.demo.cxc.compoundview.com.demo.cxc.entity.ToDoItem;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends ActionBarActivity implements View.OnClickListener {

    private EditText new_item_et;
    private Button commit_bt;
    private ListView todo_list;

    private List<ToDoItem> toDoItemList;
    private ToDoItemAdapter toDoItemAdapter;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initViews();
    }
    /*初始化控件，变量*/
    private void initViews() {


        new_item_et=(EditText)findViewById(R.id.new_item_et);
        commit_bt=(Button)findViewById(R.id.commit_bt);
        todo_list=(ListView)findViewById(R.id.todo_list);

        commit_bt.setOnClickListener(this);

        toDoItemList=new ArrayList<ToDoItem>();
        toDoItemAdapter=new ToDoItemAdapter(this,R.layout.todo_item,toDoItemList);

        //ListView注册Adapter
        todo_list.setAdapter(toDoItemAdapter);


    }

    @Override
    protected void onResume() {
        super.onResume();

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.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();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onClick(View v) {
        ToDoItem newItem=new ToDoItem(new_item_et.getText().toString());
        toDoItemList.add(0,newItem);
        toDoItemAdapter.notifyDataSetChanged();
    }
}

其中ListView中的每一个Item的布局todo_item.xml
如下：

<?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="wrap_content"
    android:orientation="horizontal">
    <TextView
        android:id="@+id/task_tv"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"/>
    <TextView
        android:id="@+id/date_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>