Dr. Ramkumar Lakshminarayanan article published in Tamil Computer Magazine. The content is about creating List in Android Application.

1. ݇†ó£Œ®™ ðô Mî ªêò™èÀœ
º‚Aòñ£ù¶ Lv† (List) à¼õ£‚°
õ‹. Þ‰î ð°FJ™ Simple Expandable List
âŠð® à¼õ£‚èô£‹ â¡ð¬î 𣘊«ð£‹.
݇†ó£Œ´ Šó£ªü‚†®¬ù à¼õ£‚è
â‚OŠC¬ù ðò¡ð´ˆ¶ƒèœ. â‚OŠC¬ù»‹
݇†ó£Œ´ âv®«èJ¬ù»‹ Þ¬íò
î÷ˆFL¼‰¶ Þôõêñ£è ðFMø‚è‹ ªêŒ¶
ªè£œ÷ô£‹.
꣡ÁèÀ‚°Þƒ«è݇†ó£Œ´âv®«è
4.0 ðò¡ð´ˆF»œ«÷¡. â‚OŠC™ ¹Fò
ÜŠO«èê¡ à¼õ£‚è File>New>Android Pro
ject â¡Á ªî£ìƒA, ÜŠO«èê¡ ªðòK¬ù
Simple Expandable List Example âù ªðò
K´ƒèœ.
Ý‚®M†®J™ «î¬õò£ù Gó™è¬÷
â¿Fì Simple Expandablelist Example Acti
vity.Java â¡ø ç¬ðL¬ù Þó†¬ì AO‚
package ram.com.example;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.widget.ExpandableListAdapter;
import
android.widget.SimpleExpandableListAdapter;
public class
SimpleExpandableListExampleActivity extends
ExpandableListActivity {
private static final String NAME = "NAME";
private static final String IS_EVEN =
"IS_EVEN";
private ExpandableListAdapter mAdapter;
@Override
public void onCreate(Bundle
savedInstanceState) {
super.onCreate(savedInstanceState);
List<Map<String, String>> groupData =
new ArrayList<Map<String, String>>();
List<List<Map<String, String>>>
childData = new ArrayList<List<Map<String,
String>>>();
for (int i = 0; i < 20; i++) {
Map<String, String> curGroupMap =
new HashMap<String, String>();
groupData.add(curGroupMap);
curGroupMap.put(NAME, "Item " + i);
curGroupMap.put(IS_EVEN, (i % 2 ==
0) ? "This group is even" : "This group is
odd"); Gó™ -1
ðì‹-1
List<Map<String, String>> children =
new ArrayList<Map<String, String>>();
for (int j = 0; j < 5; j++) {
Map<String, String> curChildMap =
new HashMap<String, String>();
children.add(curChildMap);
// curChildMap.put(NAME, "Child " +
j);
curChildMap.put(IS_EVEN, (j % 2
== 0) ? "Hello " + j: "Good Morning "+ j);
}
childData.add(children);
}
// Set up our adapter
mAdapter = new
SimpleExpandableListAdapter(
this,
groupData,
android.R.layout.simple_expandable_list_item
_1,
new String[] { NAME, IS_EVEN },
new int[] { android.R.id.text1,
android.R.id.text2 },
childData,
android.R.layout.simple_expandable_list_item
_2,
new String[] { NAME, IS_EVEN },
new int[] { android.R.id.text1,
android.R.id.text2 }
);
setListAdapter(mAdapter);
}
݇†ó£Œ®™ Lv†
à¼õ£‚°õ¶ âŠð®?

2. Ý¡†ó£Œ´ -2
Þ󣋰ñ£˜ ªô†²Iï£ó£òí¡
19
ªêŒ»ƒèœ. Gó™-1™
ªè£´‚èŠð†´œ
֦.
Þ‰î Lv†®¡
ܬñŠH¡ Itemâ¡
ðî¬ù AO‚ ªêŒî
¾ì¡ Hello>Good
M o r n i n g > H e l l o 2 >
Good Morning3> Hello
4 â¡Á‹ Item AO‚
ªêŒî¾ì¡ Hello>
Good Morning1 >Hello
2>Good Morning3>
Hello 4 â¡Á Item
1-™ Þ¼‰¶ 19 õ¬ó
àœ÷ â‰î Item
AO‚ ªêŒî£½‹ Lv† à¼õ£°õ Þ‰î
Gó™ ðò¡ð´Aø¶.
Þ‰î GóL™ Array List, Hash Map ñŸÁ‹
List ðò¡ð´ˆîŠð†´œ÷¶. Þî¬ù îMó
ExpandableListAdapter ñŸÁ‹ SimpleExpan
dable List Adapter ðò¡ð´ˆîŠð†´œ÷¶.
ªð¼‹ð£ô£ù ÜŠO«èê¡èO™ A÷£v
Ýù¶ Ý‚®M†®J¬ù«ò Extend ªêŒòŠ
ð†®¼‚°‹. Þ‰î GóL™ Expandable List
Activity - ä Extend ªêŒ¶œ«÷£‹.
Adapter â¡ø ñ£PL Íô‹ List Adapter
«î£¡P»œ÷ ñFŠ¹èœ ܬñ‰¶œ÷ù.
ðì‹ 1 MKõ¬ìò£î Lv†®¬ù F¬óJ™
裆ìŠð†´œ÷¶. ðì‹ 2 ñŸÁ‹ 3 MK‰î
Lv†¬ì F¬óJ™ 裆ìŠð†´œ÷¶.
Ü´ˆî ꣡ø£è Custom Expandable List
à¼õ£‚°õ¬î 𣘊«ð£‹. ¹Fò Šó£
ªü‚†¬ì à¼õ£‚A Üî¡ ªðò¬ó Custom
Expandable List â¡Á ªè£´ƒèœ. Import ðò¡
ð´ˆF android.view ñŸÁ‹ android.wid get -ä
ðò¡ð´ˆ¶ñ£Á GóL¬ù ܬñ‚è «õ‡
´‹.
CustomExpandabl
eList A֣v Ex
pandable List Activity
Íô‹ Extend ªêŒ»
ñ£Áܬñ‚è«õ‡
´‹. my Expand List
Adapterâ¡ø A÷£v
C¬ù à¼õ£‚°‹
F¬óJ™ «î£¡Á
õîŸè£ù îèõ™èœ
Þ¼‚è «õ‡´‹.
꣡ø£è groups ñŸ
Á‹ Children.
Þî¬ù F¬óJ™
ܬñ»‹ º¬ø ñŸ
Á‹ ⃰ «î£¡ø
ðì‹-2
ðì‹-3
ðì‹-4
ðì‹-5
ðì‹-6

3. int groupPos =
ExpandableListView.getPackedPositionGroup(inf
o.packedPosition);
int childPos =
ExpandableListView.getPackedPositionChild(info
.packedPosition);
Toast.makeText(this, title + ": Child "
+ childPos + " clicked in group " + groupPos,
Toast.LENGTH_SHORT).show();
return true;
} else if (type ==
ExpandableListView.PACKED_POSITION_TYPE_
GROUP) {
int groupPos =
ExpandableListView.getPackedPositionGroup(inf
o.packedPosition);
Toast.makeText(this, title + ": Group "
+ groupPos + " clicked",
Toast.LENGTH_SHORT).show();
return true;
}
return false;
}
public class MyExpandableListAdapter
extends BaseExpandableListAdapter {
private String[] groups = { "Android
Versions", "Android Phones" };
private String[][] children = {
{ "IceCream Sandwitch",
"Gingerboard", "Android 2.0", "Android 1.6" },
{ "Razr", "Sony Ericsson", "Galaxy
Tab", "Galaxy" }
};
public Object getChild(int groupPosition,
int childPosition) {
return
children[groupPosition][childPosition];
}
public long getChildId(int groupPosition,
int childPosition) {
return childPosition;
}
public int getChildrenCount(int
groupPosition) {
return children[groupPosition].length;
}
public TextView getGenericView() {
AbsListView.LayoutParams lp = new
AbsListView.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT, 64);
TextView textView = new
TextView(CustomExpandableList.this);
textView.setLayoutParams(lp);
package ram.com.CustomExpandableList;
import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.view.ContextMenu;
import
android.view.ContextMenu.ContextMenuInfo;
import android.view.Gravity;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import
android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import
android.widget.ExpandableListView.Expandabl
eListContextMenuInfo;
import android.widget.TextView;
import android.widget.Toast;
public class CustomExpandableList extends
ExpandableListActivity {
ExpandableListAdapter mAdapter;
@Override
public void onCreate(Bundle
savedInstanceState) {
super.onCreate(savedInstanceState);
// Set up our adapter
mAdapter = new
MyExpandableListAdapter();
setListAdapter(mAdapter);
registerForContextMenu(getExpandableListVie
w());
}
@Override
public void
onCreateContextMenu(ContextMenu menu,
View v, ContextMenuInfo menuInfo) {
menu.setHeaderTitle("Sample menu");
menu.add(0, 0, 0, "Sample action");
}
@Override
public boolean
onContextItemSelected(MenuItem item) {
ExpandableListContextMenuInfo info =
(ExpandableListContextMenuInfo)
item.getMenuInfo();
String title = ((TextView)
info.targetView).getText().toString();
int type =
ExpandableListView.getPackedPositionType(inf
o.packedPosition);
if (type ==
ExpandableListView.PACKED_POSITION_TYPE
_CHILD) {

4. textView.setGravity(Gravity.CENTER_VERTI
CAL | Gravity.LEFT);
textView.setPadding(36, 0, 0, 0);
return textView;
}
public View getChildView(int
groupPosition, int childPosition, boolean
isLastChild,
View convertView, ViewGroup
parent) {
TextView textView =
getGenericView();
textView.setText(getChild(groupPosition,
childPosition).toString());
return textView;
}
public Object getGroup(int
groupPosition) {
return groups[groupPosition];
}
public int getGroupCount() {
return groups.length;
}
public long getGroupId(int groupPosition)
{
return groupPosition;
}
public View getGroupView(int
groupPosition, boolean isExpanded, View
convertView,
ViewGroup parent) {
TextView textView = getGenericView();
textView.setText(getGroup(groupPosition).toStr
ing());
return textView;
}
public boolean isChildSelectable(int
groupPosition, int childPosition) {
return true;
}
public boolean hasStableIds() {
return true;
}
}
}
- ªî£ì¼‹
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ðì‹-7 ðì‹-8
ðì‹-9
«õ‡´‹ â¡ðî¬ù»‹
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àœ÷¶. (ðì‹-4) Lv†
âšõ£Á«î£¡Á‹â¡Á
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÷¶. ðì‹-5™ «î˜‰ªî
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ܬñŠ¹ 裆ìŠð†´œ
֦.
ðì‹-6™ Lv†®¬ù
«î˜‰ªî´ˆî¾ì¡ MK
õ¬ì‰î ªêò™ F¬óJ™
裇H‚èŠð†´œ÷¶.
«î˜¾ ªêŒ¶ 衆
«ó£™ AO‚ ªêŒî£™
ðì‹7 «ð£¡ø F¬ó
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ðì‹-8™ 裇H‚èŠð†
´œ÷¶.
«î˜¾ ªêŒî Lv†
®Ÿ° ãŸð îèõ™ toast
ðò¡ð´ˆFù£™ ðì‹-9™
àœ÷¶ «ð£¡Á «î£¡
Á‹.