Android:自定义ListView

android提供的ListView在很多情况下满足不了我们的展现需求,这里我以一个图书列表为例,实现自定义的ListView

先看下要实现的效果,左侧显示图片,右边显示标题以及章节等信息,实现步骤如下:

1. 创建一个用于控制每行显示效果的layout,名称为bookshelf

 

<?xml version="1.0" encoding="utf-8"?>

<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent" >



    <TableRow

        android:layout_width="wrap_content"

        android:layout_height="wrap_content" >



        <ImageView

            android:id="@+id/book_image"

            android:layout_width="80dip"

            android:layout_height="80dip"

            android:padding="5dip"

            android:paddingLeft="0dip" />



        <LinearLayout

            android:layout_width="match_parent"

            android:layout_height="wrap_content"

            android:orientation="vertical" >



            <TextView

                android:id="@+id/book_name"

                android:layout_width="match_parent"

                android:layout_height="wrap_content"

                android:layout_marginBottom="10dip"

                android:layout_marginTop="2dip"

                android:textIsSelectable="true" />



            <LinearLayout

                android:layout_width="match_parent"

                android:layout_height="wrap_content"

                android:orientation="horizontal"

                android:layout_marginBottom="5dip" >



                <TextView

                    android:id="@+id/book_no_read_num"

                    android:layout_width="wrap_content"

                    android:layout_height="wrap_content"

                    android:textIsSelectable="true"

                    android:textSize="12sp" />



                <ImageView

                    android:id="@+id/book_has_update"

                    android:layout_width="wrap_content"

                    android:layout_height="wrap_content"

                    android:layout_marginLeft="5dip"

                    android:layout_marginTop="3dip"

                    android:visibility="gone"

                    android:contentDescription="@string/has_update"

                    android:src="@drawable/ic_new" />

            </LinearLayout>



            <TextView

                android:id="@+id/book_lasttitle"

                android:layout_width="240dip"

                android:layout_height="wrap_content"

                android:ellipsize="end"

                android:paddingRight="5dip"

                android:singleLine="true"

                android:textIsSelectable="true"

                android:textSize="12sp" />

        </LinearLayout>

    </TableRow>



</TableLayout>

2. 创建一个新的ListViewAdapter,名称为bookshelfListViewAdapter

 

 

package com.brook.freenovelread.service;





import java.util.ArrayList;



import android.content.Context;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.ImageView;

import android.widget.TextView;



import com.brook.freenovelread.R;

import com.brook.freenovelread.object.BookData;

import com.brook.freenovelread.utility.HttpUtility;



public class bookshelfListViewAdapter extends BaseAdapter {



    private ArrayList<BookData> bookshelfList = null;

    private Context             context       = null;



    /**

     * 构造函数,初始化Adapter,将数据传入

     * @param bookshelfList

     * @param context

     */

    public bookshelfListViewAdapter(ArrayList<BookData> bookshelfList, Context context) {

        this.bookshelfList = bookshelfList;

        this.context = context;

    }



    @Override

    public int getCount() {

        return bookshelfList == null ? 0 : bookshelfList.size();

    }



    @Override

    public Object getItem(int position) {

        return bookshelfList == null ? null : bookshelfList.get(position);

    }



    @Override

    public long getItemId(int position) {

        return position;

    }



    @Override

    public View getView(int position, View convertView, ViewGroup parent) {

        //装载view

        LayoutInflater layoutInflater = LayoutInflater.from(this.context);

        View view = layoutInflater.inflate(R.layout.bookshelf, null);



        //获取控件

        ImageView bookImageView = (ImageView) view.findViewById(R.id.book_image);

        TextView bookNameTextView = (TextView) view.findViewById(R.id.book_name);

        TextView bookNoReadNumTextView = (TextView) view.findViewById(R.id.book_no_read_num);

        TextView bookLastTitleView = (TextView) view.findViewById(R.id.book_lasttitle);

        ImageView bookHasUpdateImageView = (ImageView) view.findViewById(R.id.book_has_update);

        //对控件赋值

        BookData bookData = (BookData) getItem(position);

        if (bookData != null) {

            bookImageView.setImageBitmap(HttpUtility.getHttpBitmap(bookData.getImageUrl()));

            bookNameTextView.setText(bookData.getName());

            Integer noReadNum = bookData.getTotalNum() - bookData.getCurrentNum();

            if (noReadNum > 0) {

                bookNoReadNumTextView.setText(noReadNum + "章节未读");

                //显示更新小图标

                bookHasUpdateImageView.setVisibility(View.VISIBLE);

            } else {

                bookNoReadNumTextView.setText("无未读章节");

                //隐藏更新小图标

                bookHasUpdateImageView.setVisibility(View.GONE);

            }

            bookLastTitleView.setText("更新至:" + bookData.getLastTitle());

        }



        return view;

    }

}

主要是对getView方法的重写,将数据插入到R.layout.bookshelf的各控件中,这里还用到了一个将网络图片下载的工具类HttpUtility,以下是工具类的代码

 

 

package com.brook.freenovelread.utility;





import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.HashMap;

import java.util.Map;



import android.graphics.Bitmap;

import android.graphics.BitmapFactory;



public class HttpUtility {



    

    /**

     * 图片资源缓存

     */

    private static Map<String, Bitmap> bitmapCache = new HashMap<String, Bitmap>();

    

    /**

     * 获取网落图片资源

     * @param url

     * @return

     */

    public static Bitmap getHttpBitmap(String url) {

        //先从缓存里找

        Bitmap bitmap = bitmapCache.get(url);

        if (bitmap != null) {

            return bitmap;

        }

        

        //从网络上下载

        URL myFileURL;      

        try {

            myFileURL = new URL(url);

            //获得连接

            HttpURLConnection conn = (HttpURLConnection) myFileURL.openConnection();

            //设置超时时间为6000毫秒，conn.setConnectionTiem(0);表示没有时间限制

            conn.setConnectTimeout(6000);

            //连接设置获得数据流

            conn.setDoInput(true);

            //不使用缓存

            conn.setUseCaches(false);

            //这句可有可无，没有影响

            //conn.connect();

            //得到数据流

            InputStream is = conn.getInputStream();

            //解析得到图片

            bitmap = BitmapFactory.decodeStream(is);

            //关闭数据流

            is.close();

        }

        catch (Exception e) {

            e.printStackTrace();

        }

        

        if (bitmap != null) {

            bitmapCache.put(url, bitmap);

        }



        return bitmap;



    }

}

3.在activity的layout文件中加上一个ListView控件

 

 

<ListView

        android:id="@+id/listview_bookshelf"

        android:layout_width="fill_parent"

        android:layout_height="0dip"

        android:layout_weight="1" />

4.在activity中调用我们写的ListViewAdapter

 

 

@Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        //设置主页面的标题栏

        requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);

        setContentView(R.layout.activity_main);

        getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.title_bar);

        

        //更新标题栏中按钮的字体大小

        Button btnManage = (Button) findViewById(R.id.btn_manage);

        btnManage.setTextSize(10);

        

        //获取书架列表数据

        ArrayList<BookData> bookshelf = new ArrayList<BookData>();

        BookData bookData = new BookData();

        bookData.setAuthor("天蚕土豆");

        bookData.setCurrentNum(1);

        bookData.setDescription("修炼一途，乃窃阴阳，夺造化，转涅盘，握生死，掌轮回。武之极，破苍穹，动乾坤！");

        bookData.setId(1);

        bookData.setImageUrl("http://www.easou.org/files/article/image/0/308/308s.jpg");

        bookData.setLastTitle("第一千两百九十四章 魔皇之手");

        bookData.setName("武动乾坤");

        bookData.setTotalNum(1294);

        

        BookData bookData2 = new BookData();

        bookData2.setAuthor("忘语");

        bookData2.setCurrentNum(2343);

        bookData2.setDescription("一个普通的山村穷小子，偶然之下，进入到当地的江湖小门派，成了一名记名弟子。他以这样的身份，如何在门派中立足？又如何以平庸的资质，进入到修仙者的行列？和其他巨枭魔头，仙宗仙师并列于山海内外？希望书友们喜欢本书！");

        bookData2.setId(2342);

        bookData2.setImageUrl("http://www.easou.org/files/article/image/0/289/289s.jpg");

        bookData2.setLastTitle("第十一卷 真仙降世 第两千三百四十三章 九目血蟾");

        bookData2.setName("凡人修仙传");

        bookData2.setTotalNum(2343);

        

        bookshelf.add(bookData);

        bookshelf.add(bookData2);

        bookshelf.add(bookData);

        bookshelf.add(bookData2);

        bookshelf.add(bookData);

        bookshelf.add(bookData2);

        

        bookshelfListViewAdapter bookshelfListViewAdapter = new bookshelfListViewAdapter(bookshelf, this);

        ListView listView = (ListView) findViewById(R.id.listview_bookshelf);

        listView.setAdapter(bookshelfListViewAdapter);

    }

这样就ok了