国外 电子 商务 网站 欣赏/网络营销的优缺点

首先还是上效果图，该ListView由四个控件组成，左边是一个图标，中间是两个TextView用于显示标题和描述，右边是一个TextView用于显示时间。

编写每一项对应的实体类

package cn.edu.zafu.myapplication;/*** Created by Administrator on 2015/1/1.*/
public class Item {private int resId;private String title;private String description;private String time;public Item(int resId, String title, String description, String time) {this.resId = resId;this.title = title;this.description = description;this.time = time;}public int getResId() {return resId;}public void setResId(int resId) {this.resId = resId;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}public String getDescription() {return description;}public void setDescription(String description) {this.description = description;}public String getTime() {return time;}public void setTime(String time) {this.time = time;}
}

编写每一项对应的布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="wrap_content"android:minHeight="60dp"tools:context=".MainActivity"><ImageViewandroid:id="@+id/item_icon"android:layout_width="32dp"android:layout_height="32dp"android:layout_alignParentLeft="true"android:layout_marginLeft="10dp"android:layout_centerVertical="true"/><LinearLayoutandroid:layout_toRightOf="@id/item_icon"android:layout_width="wrap_content"android:layout_height="match_parent"android:layout_centerVertical="true"android:layout_marginLeft="10dp"android:gravity="center_vertical"android:orientation="vertical"><TextViewandroid:id="@+id/item_title"android:layout_width="wrap_content"android:layout_height="wrap_content"android:textSize="18sp"/><TextViewandroid:id="@+id/item_description"android:layout_width="wrap_content"android:layout_height="wrap_content"android:textColor="#aaa"android:textSize="15sp"/></LinearLayout><TextViewandroid:id="@+id/item_time"android:layout_width="60dp"android:layout_height="wrap_content"android:layout_alignParentRight="true"android:layout_centerVertical="true"android:textSize="12sp"/>
</RelativeLayout>

主布局文件

<RelativeLayout 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"tools:context=".MainActivity"><ListViewandroid:id="@+id/listview"android:layout_width="match_parent"android:layout_height="match_parent"></ListView></RelativeLayout>

继承ArrayAdapter编写适配器

package cn.edu.zafu.myapplication;import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;import java.util.List;public class MyArrayAdapter extends ArrayAdapter<Item> {private int resourceId;public MyArrayAdapter(Context context, int resource, List<Item> objects) {super(context, resource, objects);this.resourceId=resource;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {Item item = getItem(position);View view;ViewHolder viewHolder;if (convertView == null) {view = LayoutInflater.from(getContext()).inflate(resourceId, null);viewHolder=new ViewHolder();viewHolder.icon= (ImageView) view.findViewById(R.id.item_icon);viewHolder.title= (TextView) view.findViewById(R.id.item_title);viewHolder.description= (TextView) view.findViewById(R.id.item_description);viewHolder.time= (TextView) view.findViewById(R.id.item_time);view.setTag(viewHolder);} else {view = convertView;viewHolder= (ViewHolder) view.getTag();}viewHolder.icon.setImageResource(item.getResId());viewHolder.title.setText(item.getTitle());viewHolder.description.setText(item.getDescription());viewHolder.time.setText(item.getTime());return view;}class ViewHolder{ImageView icon;TextView title;TextView description;TextView time;}
}

Activity的代码

package cn.edu.zafu.myapplication;import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;import java.util.ArrayList;
import java.util.List;public class MainActivity extends ActionBarActivity {private List<Item> items=new ArrayList<Item>();@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initMenus();//初始化数据MyArrayAdapter adapter=new MyArrayAdapter(this,R.layout.item_layout,items);//新建自己的适配器ListView listView= (ListView)findViewById(R.id.listview);listView.setAdapter(adapter);//设置适配器listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> parent, View view, int position, long id) {Item item=items.get(position);//获得点击项对应实体类Toast.makeText(getApplicationContext(),item.getTitle(),Toast.LENGTH_SHORT).show();}});}//数据初始化private void initMenus() {Item train=new Item(R.drawable.car,"ECMobile","蓝天神鹰","下午1:15");items.add(train);Item road=new Item(R.drawable.car,"YiiBook讨论群","UM5","下午2:23");items.add(road);Item history=new Item(R.drawable.car,"腾讯新闻","上海踩踏事件伤者惊魂","下午12:15");items.add(history);}
}

在实现的过程中主要遇到两个问题

第一个是ListView最下面的一项的横线不见了，解决方法是将ListViewd layout_height设为match_parent而不是wrap_content

第二是设置了子项的高度后不起作用，解决方法是设置layout_height属性为wrap_content，增加minHeight属性即此文中的minHeight="60dp"