android控件开发之ExpandableListActivity（二）

浏览数：32 / 时间：2015年06月11日

android控件开发之ExpandableListActivity（二）

本博文主要讲述的是使用ExpandableListActivity创建一个类似QQ中好友列表的功能。下面我们直接来看实现的代码吧。

本实例中有一个Activity，和一个主布局文件。其他的一级目录和二级目录分别是通过重写ExpandableListActivity中的getGroupView（）和getChildView（）方法来实现的布局

MainActivity.java代码如下：

此Activity主要是extends自ListActivity类，

package com.example.expandablelistactivity;

import java.util.ArrayList;
import java.util.HashMap;
import android.os.Bundle;
import android.app.ListActivity;
import android.database.DataSetObserver;
import android.graphics.Color;
import android.view.Gravity;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.SimpleExpandableListAdapter;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.TextView;

/*

主要是通过重写ExpandableListAdapter（）中的相关方法来实现

*/

public class MainActivity extends ListActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

//匿名内部类，重写ExpandableListAdapter类的方法
final ExpandableListAdapter ela = new ExpandableListAdapter() {
//设置组视图的图片
int[] logos = new int[] { R.drawable.ic_launcher, R.drawable.ic_launcher,R.drawable.ic_launcher};
//设置组视图的显示文字
private String[] generalsTypes = new String[] { "group1", "group2" };
//子视图显示文字
private String[][] generals = new String[][] {
{ "child1data1", "child1data2", "child1data3"},
{ "child2data1"}

};
//子视图图片
public int[][] generallogos = new int[][] {
{ R.drawable.list1, R.drawable.list2,
R.drawable.list3 },
{ R.drawable.list4 } };

//自己定义一个获得文字信息的方法
TextView getTextView() {
//设置textView的高度和宽度
AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
TextView textView = new TextView(
MainActivity.this);
textView.setLayoutParams(lp);
textView.setGravity(Gravity.CENTER_VERTICAL);
textView.setPadding(10, 10, 10, 10);
textView.setTextSize(15);
textView.setTextColor(Color.BLACK);
return textView;
}

//重写ExpandableListAdapter中的各个方法
@Override
public int getGroupCount() {
// TODO Auto-generated method stub
return generalsTypes.length;
}

@Override
public Object getGroup(int groupPosition) {
// TODO Auto-generated method stub
return generalsTypes[groupPosition];
}

@Override
public long getGroupId(int groupPosition) {
// TODO Auto-generated method stub
return groupPosition;
}

@Override
public int getChildrenCount(int groupPosition) {
// TODO Auto-generated method stub
return generals[groupPosition].length;
}

@Override
public Object getChild(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return generals[groupPosition][childPosition];
}

@Override
public long getChildId(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return childPosition;
}

@Override
public boolean hasStableIds() {
// TODO Auto-generated method stub
return true;
}

@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
//创建一个LinearLayout视图
LinearLayout ll = new LinearLayout(
MainActivity.this);
ll.setOrientation(0);

//创建一个ImageView对象
ImageView logo = new ImageView(MainActivity.this);
logo.setImageResource(logos[groupPosition]);
logo.setPadding(50, 0, 0, 0);
//在LinearLayout中添加一个ImageView
ll.addView(logo);

//创建一个TextView对象
TextView textView = getTextView();
textView.setTextColor(Color.BLACK);
textView.setText(getGroup(groupPosition).toString());
//将TextView添加到LinearLayout中
ll.addView(textView);

return ll;
}

@Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
//创建一个LinearLayout对象
LinearLayout ll = new LinearLayout(
MainActivity.this);
ll.setOrientation(0);

//创建一个ImageView对象
ImageView generallogo = new ImageView(
MainActivity.this);
generallogo.setImageResource(generallogos[groupPosition][childPosition]);
generallogo.setPadding(5, 5, 5, 5);

//将imageView对象添加到LinearLayout对象中
ll.addView(generallogo);

//创建一个TextView对象
TextView textView = getTextView();
textView.setText(getChild(groupPosition, childPosition)
.toString());

ll.addView(textView);
return ll;
}

@Override
public boolean isChildSelectable(int groupPosition,
int childPosition) {
// TODO Auto-generated method stub
return true;
}

@Override
public boolean areAllItemsEnabled() {
// TODO Auto-generated method stub
return false;
}

@Override
public long getCombinedChildId(long groupId, long childId) {
// TODO Auto-generated method stub
return 0;
}

@Override
public long getCombinedGroupId(long groupId) {
// TODO Auto-generated method stub
return 0;
}

@Override
public boolean isEmpty() {
// TODO Auto-generated method stub
return false;
}

@Override
public void onGroupCollapsed(int groupPosition) {
// TODO Auto-generated method stub

}

@Override
public void onGroupExpanded(int groupPosition) {
// TODO Auto-generated method stub

}

@Override
public void registerDataSetObserver(DataSetObserver observer) {
// TODO Auto-generated method stub

}

@Override
public void unregisterDataSetObserver(DataSetObserver observer) {
// TODO Auto-generated method stub

}};

//给ExpandableListView设置SimpleExpandableListAdapter适配器
ExpandableListView expandableListView = (ExpandableListView)findViewById(android.R.id.list);
expandableListView.setAdapter(ela);

//绑定ExpandableListView child的监听器
expandableListView.setOnChildClickListener(new expandableChildLisenter());

}

//实现二级菜单监听器
class expandableChildLisenter implements OnChildClickListener{

@Override
public boolean onChildClick(ExpandableListView parent, View v,
int groupPosition, int childPosition, long id) {
// TODO Auto-generated method stub
System.out.println("group = " + groupPosition);
System.out.println("child = " + childPosition);
System.out.println("id = " + id);

return false;
}

}

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

}