Android 自定义 ExpandableListView

Android中有一控件是ExpandableListView，比ListView更高级，ExpandableListView的效果很实用，比如因为需要查看一堆文件的目录结构或者开发像QQ好友那样的界面，就应该使用Expandablelistview。

本文最终效果如下：



首先是Activity代码，实际开发中数据（包括父item，子item及图片，Expandablelistview布局也可以轻易更改）可以很方便的从数据库或网络动态取得，本文方便起见数据就先定死了。

public class C_ExpandableListView extends Activity {

ExpandableListView expandableList;

public String[] str1 = { "我的好友", "陌生人", "黑名单","yilee","good","哈哈哈" };

public String[] str2 = { "我了个去", "哈哈", "蟹", "XX", "我去" };

public String[] str3 = { "哈哈", "蟹", "XX", "我去" };

public String[] str4 = { "我了个去", "蟹", "XX", "我去" };

public String[] str5 = { "我了个去", "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;

}

}

}

其中类TreeViewAdapter是我们的自定义Adapter，继承自BaseExpandableListAdapter。

getChildrenCount比较麻烦,因为么个子item数目并不一样，可以把子数据放入一个String三维数组，这样只需return str[position]，返回的便是子item的数据，样在getChildView在也应该这样设置：textview.setText(str[position][childPosition]);

我们需要三个布局文件，一个是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>

第二个是描述父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>

最后一个是描述子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>

这样就可以轻易实现ExpandableListAdapter 高度自定义了。