仿QQ下拉列表

import java.util.*;
import android.app.Activity;
import android.os.Bundle;
import android.view.*;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;

public class ExpandActivity extends Activity {
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_expand);
		//效果
		overridePendingTransition(android.R.anim.slide_in_left,android.R.anim.slide_out_right);
			
		ExpandableListView expandableListView = (ExpandableListView)findViewById(R.id.expandableListView);  
		expandableListView.setAdapter(new ExpandableAdapter(ExpandActivity.this)); 
	}

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




/** 定義一個expandAdapter類繼承 BaseExpandableListAdapter*/
 class  ExpandableAdapter extends  BaseExpandableListAdapter {
     private  List<String> groupArray;  
     private  List<ArrayList<String>> childArray;
	 private Activity activity;  
	 
	 //初始化,這裏可以考慮父節點用數組，子節點用二維數組
	 private void initList(){
		 groupArray = new  ArrayList<String>();  
		 childArray = new  ArrayList<ArrayList<String>>();  
		   
		 groupArray.add("排序算法" );  
		 groupArray.add("Android之路" );  
		   
		 ArrayList<String> tempArray = new  ArrayList<String>();  
		 tempArray.add("冒泡排序" );  
		 tempArray.add("插入排序" );  
		 tempArray.add("選擇排序" );  
		 
		 ArrayList<String> tempArray2 = new  ArrayList<String>();  
		 tempArray2.add("深入Adapt" );  
		 tempArray2.add("通知管理" );  
		 tempArray2.add("service管理" );  
		   
		 childArray.add(tempArray);  
		 childArray.add(tempArray2);  
		 
    }
	 
	 //構造方法
	 public ExpandableAdapter(Activity a){
		 activity=a;
		 initList();
	 }
	 
	@Override
	public int getGroupCount() {
		 return  groupArray.size();  
	}

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

	@Override //獲得父節點
	public Object getGroup(int groupPosition) {
		  return  groupArray.get(groupPosition);  
	}

	@Override  //獲得子節點
	public Object getChild(int groupPosition, int childPosition) {
	    return  childArray.get(groupPosition).get(childPosition);  
	}

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

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

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

	@Override
	public View getGroupView(int groupPosition, boolean isExpanded,
			View convertView, ViewGroup parent) {
		 String string = groupArray.get(groupPosition);  
	     return  getGenericView(string,1);  
	}

	@Override
	public View getChildView(int groupPosition, int childPosition,
			boolean isLastChild, View convertView, ViewGroup parent) {
		String string = childArray.get(groupPosition).get(childPosition);  
	    return  getGenericView(string,2);
	}

	@Override  //子節點是否可選
	public boolean isChildSelectable(int groupPosition, int childPosition) {
		 return  true ;  
	}
	
	
	/** 查看子節點的視圖   */
    public TextView getGenericView(String string,int statu)  
    {  
        AbsListView.LayoutParams layoutParams = new  AbsListView.LayoutParams(  
                ViewGroup.LayoutParams.FILL_PARENT, 64 );  
        TextView text = new  TextView(activity);  
        text.setLayoutParams(layoutParams);  
        if(statu==2)
           text.setBackgroundColor(getResources().getColor(R.color.pink));
        else 
           text.setBackgroundColor(getResources().getColor(R.color.gray));

        text.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);  
        text.setPadding(36 , 0 , 0 , 0 );  
        text.setText(string);  
        return  text;  
    } 
	 
 }
}

佈局文件如下：

<LinearLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".ExpandActivity" 
    android:orientation="vertical">

     <ExpandableListView   
    android:id ="@+id/expandableListView"   
    android:layout_width ="match_parent"   
    android:layout_height ="wrap_content"   
        />   
</LinearLayout>

至於三級或多級樹，我這裏不建議，能簡化的儘量簡化，使用最基礎的二級菜單會好些。