这段代码如何重写ListView

Question

网上的例子如下：

main.xml:定义Activity的界面布局:

<?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"

android:id = "@+id/expandableListView"
android:layout_width = "fill_parent"
android:layout_height = "fill_parent"
android:drawSelectorOnTop = "false"/>

group.xml:定义一级列表的布局方式:

<?xml version="1.0" encoding="utf-8"?>
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation = "horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:id = "@+id/textView01"
android:layout_width = "match_parent"
android:layout_height = "match_parent"
android:paddingLeft = "60px"
android:paddingTop = "10px"
android:paddingBottom = "10px"
android:textSize = "26sp"/>

child.xml:定义二级列表的布局方式:

<?xml version="1.0" encoding="utf-8"?>
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation = "horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:layout_gravity = "center_vertical"
android:id = "@+id/imageView01"
android:layout_width = "70px"
android:layout_height = "70px"
android:paddingLeft = "30px"
android:paddingTop = "2px"
android:paddingBottom = "5px"
android:src = "@drawable/abc"/>
android:layout_gravity = "center_vertical"
android:id = "@+id/childTo"
android:layout_width = "match_parent"
android:layout_height = "match_parent"
android:paddingLeft = "30px"
android:paddingTop = "10px"
android:paddingBottom = "5px"
android:textSize = "30sp"/>

ExpandableList.java代码如下：

package snowfox.expandable;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

public class ExpandableList extends Activity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ExpandableListView elv = (ExpandableListView)findViewById(R.id.expandableListView);

//准备一级列表中显示的数据:2个一级列表,分别显示"group1"和"group2"
List> groups = new ArrayList>();
Map group1 = new HashMap();
group1.put("group", "group1");
Map group2 = new HashMap();
group2.put("group", "group2");
groups.add(group1);
groups.add(group2);

//准备第一个一级列表中的二级列表数据:两个二级列表,分别显示"childData1"和"childData2"
List> child1 = new ArrayList>();
Map child1Data1 = new HashMap();
child1Data1.put("child", "child1Data1");
Map child1Data2 = new HashMap();
child1Data2.put("child", "child1Data2");
child1.add(child1Data1);
child1.add(child1Data2);

//准备第二个一级列表中的二级列表数据:一个二级列表,显示"child2Data1"
List> child2 = new ArrayList>();
Map child2Data1 = new HashMap();
child2Data1.put("child", "child2Data1");
child2.add(child2Data1);
//用一个list对象保存所有的二级列表数据
List>> childs = new ArrayList>>();
childs.add(child1);
childs.add(child2);

ExpandableAdapter viewAdapter = new ExpandableAdapter(this, groups, childs);
elv.setAdapter(viewAdapter);
}

//自定义的ExpandListAdapter
class ExpandableAdapter extends BaseExpandableListAdapter
{
private Context context;
List> groups;
List>> childs;

/*

• 构造函数:
• 参数1:context对象
• 参数2:一级列表数据源

• 参数3:二级列表数据源
  */
  public ExpandableAdapter(Context context, List> groups, List>> childs)
  {
  this.groups = groups;
  this.childs = childs;
  this.context = context;
  }
  @Override
  public Object getChild(int groupPosition, int childPosition)
  {
  return childs.get(groupPosition).get(childPosition);
  }

  @Override
  public long getChildId(int groupPosition, int childPosition)
  {
  return childPosition;
  }

  //获取二级列表的View对象
  @Override
  public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView,
  ViewGroup parent)
  {
  @SuppressWarnings("unchecked")
  String text = ((Map) getChild(groupPosition, childPosition)).get("child");
  LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
  //获取二级列表对应的布局文件, 并将其各元素设置相应的属性
  LinearLayout linearLayout = (LinearLayout) layoutInflater.inflate(R.layout.child, null);
  TextView tv = (TextView) linearLayout.findViewById(R.id.childTo);
  tv.setText(text);
  ImageView imageView = (ImageView)linearLayout.findViewById(R.id.imageView01);
  imageView.setImageResource(R.drawable.abc);

  return linearLayout;
  }

  @Override
  public int getChildrenCount(int groupPosition)
  {
  return childs.get(groupPosition).size();
  }

  @Override
  public Object getGroup(int groupPosition)
  {
  return groups.get(groupPosition);
  }
  @Override
  public int getGroupCount()
  {
  return groups.size();
  }

  @Override
  public long getGroupId(int groupPosition)
  {
  return groupPosition;
  }

  //获取一级列表View对象
  @Override
  public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent)
  {
  String text = groups.get(groupPosition).get("group");
  LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

  //获取一级列表布局文件,设置相应元素属性
  LinearLayout linearLayout = (LinearLayout) layoutInflater.inflate(R.layout.group, null);
  TextView textView = (TextView)linearLayout.findViewById(R.id.textView01);
  textView.setText(text);
  return linearLayout;
  }

  @Override
  public boolean hasStableIds()
  {
  return false;
  }

  @Override
  public boolean isChildSelectable(int groupPosition, int childPosition)
  {
  return false;
  }

  }
  }

Answer 1

你可以创建一个类继承ListView.
比如 类名 MyListView.java 继承ListView
在包名为 com.tracy 中

接下来就是在xml里使用刚重写的ListView了
一般在xml用系统的listView控件是这样写的
(注：那个属性名不一对哦，是手写的)
使用自己重写的方法

这样就可以了，不过你会发现自己重写的控件在xml里不能使用补全方式还获取控件属性。这个是正常的，如果要显示的话需要配置一些东西。

好了。这样就可以了。希望你能看懂.