android學習筆記22：可展開的ListView

有時在寫程式時，我們希望一個listview能展開其下的子類目，在android中可以通過使用ExpandAbleListView來實現，只需要在代碼裡為ExpandAbleListView設定一個ExpandAbleLIstAdapter的資料來源即可。

<?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"><ExpandableListView android:id="@+id/list" android:layout_width="fill_parent" android:layout_height="wrap_content" android:childIndicator="@drawable/icon" ></ExpandableListView></LinearLayout>

public class ExpandableListViewTest extends Activity{@Overridepublic void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.main);//建立一個BaseExpandableListAdapter對象ExpandableListAdapter adapter = new BaseExpandableListAdapter(){int[] logos = new int[]{R.drawable.sunyz_1, R.drawable.sunyz_6,R.drawable.sunyz_7}; private String[] CDs = new String[]{ "風箏", "完美的一天", "是時候"};private String[][] songs = new String[][]{ { "綠光", "不是真的愛我", "愛情字典", "練習" },{ "Honey Honey", "心愿", "明天晴天", "隱形人" },{ "愚人的國度", "是時候" , "世說心語" }};//擷取指定組位置、指定子清單項目處的子清單項目資料@Overridepublic Object getChild(int groupPosition, int childPosition){return songs[groupPosition][childPosition];}@Overridepublic long getChildId(int groupPosition, int childPosition){return childPosition;}@Overridepublic int getChildrenCount(int groupPosition){return songs[groupPosition].length;}private TextView getTextView(){//用於實現條目的虛擬列表的基類. 這裡的列表沒有空間的定義。 例如，該類的子類可以以網格的形式、走馬燈的形式顯示，或者作為堆棧等等AbsListView.LayoutParams lp = new AbsListView.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, 64);  //設定寬和高 TextView textView = new TextView(ExpandableListViewTest.this);textView.setLayoutParams(lp);textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);textView.setPadding(36, 0, 0, 0);textView.setTextSize(20);return textView;}//該方法決定每個子選項的外觀@Overridepublic View getChildView(int groupPosition, int childPosition,boolean isLastChild, View convertView, ViewGroup parent){TextView textView = getTextView();textView.setText(getChild(groupPosition, childPosition).toString());return textView;}//擷取指定組位置處的組資料@Overridepublic Object getGroup(int groupPosition){return CDs[groupPosition];}@Overridepublic int getGroupCount(){return CDs.length;}@Overridepublic long getGroupId(int groupPosition){return groupPosition;}//該方法決定每個組選項的外觀@Overridepublic View getGroupView(int groupPosition, boolean isExpanded,View convertView, ViewGroup parent){LinearLayout ll = new LinearLayout(ExpandableListViewTest.this);ll.setOrientation(0);ImageView logo = new ImageView(ExpandableListViewTest.this);logo.setImageResource(logos[groupPosition]);ll.addView(logo);TextView textView = getTextView();textView.setText(getGroup(groupPosition).toString());ll.addView(textView);return ll;}@Overridepublic boolean isChildSelectable(int groupPosition, int childPosition){return true;}@Overridepublic boolean hasStableIds(){return true;}};ExpandableListView expandListView = (ExpandableListView)findViewById(R.id.list);expandListView.setAdapter(adapter);}}