Android:自定义ListView
0
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
fmms
11年前提问