Android中有一控件是ExpandableListView，比ListView更高級，ExpandableListView的效果很實用，比如因為需要查看一堆文件的目錄結構或者開發像QQ好友那樣的界面，就應該使用Expandablelistview。
本文最終效果如下：
首先是Activity代碼，實際開發中數據（包括父item，子item及圖片，Expandablelistview布局也可以輕易更改）可以很方便的從數據庫或網絡動態取得，本文方便起見數據就先定死了。
public class C_ExpandableListView extends Activity {
ExpandableListView expandableList;
public String[] str1 = { "我的好友", "陌生人", "黑名單","yilee","good","哈哈哈" };
public String[] str2 = { "我了個去", "哈哈", "蟹", "XX", "我去" };
public String[] str3 = { "哈哈", "蟹", "XX", "我去" };
public String[] str4 = { "我了個去", "蟹", "XX", "我去" };
public String[] str5 = { "我了個去", "蟹", "XX", "我去" };
public String[] str6 = { "yilee", "哈哈", "蟹", "XX", "我去" };
public String[] str7 = { "哈哈", "蟹", "XX", "我去" };
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
expandableList = (ExpandableListView) C_ExpandableListView.this
.findViewById(R.id.ExpandableListView01);
expandableList.setAdapter(new TreeViewAdapter(this));
}
public class TreeViewAdapter extends BaseExpandableListAdapter {
private LayoutInflater inflater;
private LayoutInflater inflater1;
public TreeViewAdapter(Context c) {
this.inflater = LayoutInflater.from(c);
this.inflater1 = LayoutInflater.from(c);
}
@Override
public Object getChild(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return 0;
}
@Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
View myView = inflater1.inflate(R.layout.cc, null);
final int a=groupPosition;
final int b=childPosition;
myView.setBackgroundResource(R.drawable.child);
TextView textview = (TextView) myView
.findViewById(R.id.TextView001);
textview.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Log.i("yileeeee", "groupPosition= "+a);
Log.i("yileeeee", "childPosition= "+b);
}
});
if(groupPosition==0){
textview.setText(str2[childPosition]);
}else if(groupPosition==1){
textview.setText(str3[childPosition]);
}else if(groupPosition==2){
textview.setText(str4[childPosition]);
}else if(groupPosition==3){
textview.setText(str5[childPosition]);
}else if(groupPosition==4){
textview.setText(str6[childPosition]);
}else if(groupPosition==5){
textview.setText(str7[childPosition]);
}
return myView;
}
@Override
public int getChildrenCount(int groupPosition) {
if(groupPosition==0){
return str2.length;
}else if(groupPosition==1){
return str3.length;
}else if(groupPosition==2){
return str4.length;
}else if(groupPosition==3){
return str5.length;
}else if(groupPosition==4){
return str6.length;
}else {
return str7.length;
}
}
@Override
public Object getGroup(int groupPosition) {
return "dd";
}
@Override
public int getGroupCount() {
return str1.length;
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
View myView = inflater.inflate(R.layout.dd, null);
myView.setBackgroundResource(R.drawable.group);
TextView textview = (TextView) myView.findViewById(R.id.TextView01);
textview.setText(str1[groupPosition]);
return myView;
}
@Override
public boolean hasStableIds() {
return false;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return false;
}
}
}
其中類TreeViewAdapter是我們的自定義Adapter，繼承自BaseExpandableListAdapter。
getChildrenCount比較麻煩,因為么個子item數目并不一樣，可以把子數據放入一個String三維數組，這樣只需return str[position]，返回的便是子item的數據，樣在getChildView在也應該這樣設置：textview.setText(str[position][childPosition]);
我們需要三個布局文件，一個是activity里面是ExpandableListView
<ExpandableListView android:id="@+id/ExpandableListView01"
android:layout_width="200dp" android:layout_height="fill_parent"
android:layout_x="20dip" android:layout_y="30dip"
android:groupIndicator="@null"android:childDivider="@drawable/child_divider"
android:clickable="true" android:scrollbarAlwaysDrawHorizontalTrack="true">
</ExpandableListView>
第二個是描述父item的布局文件
<TextView android:id="@+id/TextView01" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:textSize="16px"
android:gravity="center">
</TextView>
最后一個是描述子item的
<ImageView android:id="@+id/ImageView01" android:layout_height="30dp" android:layout_width="30dp" android:background="@drawable/head"> </ImageView>
<TextView android:id="@+id/TextView001" android:layout_height="fill_parent"
android:layout_width="fill_parent" android:gravity="center">
</TextView>
這樣就可以輕易實現ExpandableListAdapter 高度自定義了。