I need to use Android ExpandableListView with custom layout for each group(groups have one child). To accomplish this, I’ve created a class which extends BaseExpandableListAdapter. On the getChildView method, I’ve created the view of each child. It works. When I click a group, its child comes with true layout. However, during the debuging, I see that it triggers getchildview method many times, so it is too slow to display child. Because there are a lot of operations on each child (db operations, dynamic sub layouts…).
There are a small project, which similar to my project(Logic and code structure are same, only layout code and code of creating each child view are different).
public class MainActivity extends Activity {
private ArrayList<String> groups;
private ArrayList<ArrayList<ArrayList<String>>> childs;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ExpandableListView l = (ExpandableListView)findViewById(R.id.expandableListView1);
loadData();
final myExpandableAdapter adapter = new myExpandableAdapter(this, groups, childs);
l.setAdapter(adapter);
}
public class myExpandableAdapter extends BaseExpandableListAdapter {
private ArrayList<String> groups;
private ArrayList<ArrayList<ArrayList<String>>> children;
private Context context;
public myExpandableAdapter(Context context, ArrayList<String> groups, ArrayList<ArrayList<ArrayList<String>>> children) {
this.context = context;
this.groups = groups;
this.children = childs;
}
@Override
public boolean areAllItemsEnabled()
{
return true;
}
public ArrayList<String> getChild(int groupPosition, int childPosition) {
return children.get(groupPosition).get(childPosition);
}
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
public View getChildView(int groupPosition, int childPosition, boolean isLastChild,View convertView, ViewGroup parent) {
String child=(String)getChild(groupPosition, childPosition).get(0);
switch (groupPosition){
case 0:
LayoutInflater inflater = (LayoutInflater)getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.child_row, null);
TextView tvPlayerName = (TextView) convertView.findViewById(R.id.tvPlayerName);
tvPlayerName.setText(child);
break;
case 1:
LayoutInflater inflater1 = (LayoutInflater) getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater1.inflate(R.layout.child_row1, null);
TextView tvPlayerName1 = (TextView) convertView.findViewById(R.id.tvPlayerName);
tvPlayerName1.setText(child);
Button btn=(Button)convertView.findViewById(R.id.button1);
btn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
TextView tv=(TextView)findViewById(R.id.tv);
tv.setText("Clicked");
}
});
break;
case 2:
LayoutInflater inflater2 = (LayoutInflater) getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater2.inflate(R.layout.child_row1, null);
TextView tvPlayerName12 = (TextView) convertView.findViewById(R.id.tvPlayerName);
tvPlayerName12.setText(child);
Button btn2=(Button)convertView.findViewById(R.id.button1);
btn2.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
TextView tv=(TextView)findViewById(R.id.tv);
tv.setText("Clicked");
}
});
break;
}
return convertView;
}
public int getChildrenCount(int groupPosition) {
return children.get(groupPosition).size();
}
public String getGroup(int groupPosition) {
return groups.get(groupPosition);
}
public int getGroupCount() {
return groups.size();
}
public long getGroupId(int groupPosition) {
return groupPosition;
}
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
String group = (String) getGroup(groupPosition);
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.expandablelistview_group, null);
}
TextView grouptxt = (TextView) convertView.findViewById(R.id.TextViewGroup);
grouptxt.setText(group);
return convertView;
}
public boolean hasStableIds() {
return true;
}
public boolean isChildSelectable(int arg0, int arg1) {
return true;
}
}
private void loadData(){
groups= new ArrayList<String>();
childs= new ArrayList<ArrayList<ArrayList<String>>>();
groups.add("Group 1");
groups.add("Group 2");
groups.add("Group 3");
childs.add(new ArrayList<ArrayList<String>>());
childs.get(0).add(new ArrayList<String>());
childs.get(0).get(0).add("Child 1 group 1");
childs.add(new ArrayList<ArrayList<String>>());
childs.get(1).add(new ArrayList<String>());
childs.get(1).get(0).add("Child 1 group 2");
childs.add(new ArrayList<ArrayList<String>>());
childs.get(2).add(new ArrayList<String>());
childs.get(2).get(0).add("Child 1 group 3");
}}
During debugging, If I click any group, it comes to String child=(String)getChild(groupPosition, childPosition).get(0); line. After break; }return convertView;, it comes to there again and again, and then it displays layout.
activity_main.xml
<RelativeLayout 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" >
<ExpandableListView
android:id="@+id/expandableListView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:layout_marginLeft="34dp" >
</ExpandableListView>
expandablelistview_group.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:id="@+id/TextViewGroup"
android:layout_width="wrap_content"
android:layout_height="50px"
android:layout_marginLeft="50px"
android:gravity="center_vertical"
>
</TextView>
child_row.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/tvPlayerName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView" />
<CheckBox
android:id="@+id/checkBox1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CheckBox" />
childrow1.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<TextView
android:id="@+id/tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Row1" />
<TextView
android:id="@+id/tvPlayerName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
Is there any suggestion to solve this.
Thanks
instead of inflating the view from
getChildViewuse Holder read here