Android ListView Tutorial

Android ListView

The traditional listbox widget in Android is known as ListView. We really need to invoke setAdapter() to provide data and child views to the ListView as well as have to connect a listener by making use of setOnItemSelectedListener() to understand when the selection has changed. With that, you now have a fully functioning listbox.

In case your activity is actually containing just a single list, then you might very well think of creating your activity as a subclass of ListActivity, as opposed to the regular Activity base class.

If you would like to personalize the layout, put the id of the ListView as @android: id/list, so ListActivity understands which widget is the main list for the activity.

Lets create a brand new android project to experiment with listview, I named my project as AndroidListView. As well as created an activity called ListViewActivity and ensure we have to extend ListActivity as this gonna consist of just a single list.

Creating Layout for ListView

main.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"
    android:orientation="vertical" >
    <TextView
        android:id="@+id/user_selection"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
    <ListView
        android:id="@android:id/list"
    	android:layout_width="fill_parent"
    	android:layout_height="fill_parent"
    	android:drawSelectorOnTop="false"
    	android:choiceMode="singleChoice"/>
</LinearLayout>

Java code to configure the list

ListViewActivity.java

package com.vimaltuts.android.listview;
import java.util.ArrayList;
import android.app.Activity;
import android.app.ListActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class ListViewActivity extends ListActivity {
    /** Called when the activity is first created. */
	private TextView userSelection;
	private static final String[] items={"Android","Bluetooth","Chrome","Docs","Email",
		"Facebook","Google","Hungary","Iphone","Korea","Machintosh",
		"Nokia","Orkut","Picasa","Singapore","Turkey","Windows","Youtube"};
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        setListAdapter(new ArrayAdapter(this,android.R.layout.simple_list_item_1,items));
        userSelection=(TextView)findViewById(R.id.selection);
    }
    public void onListItemClick(ListView parent,View v,int pos,long id){
    	userSelection.setText(items[pos]);
    }
}

With ListActity, we can set the list adapter by using setListAdapter() in this example, providing an ArrayAdapter wrapping an array of strings. Then we need to override onListItemClick(), to determine as soon as the list selection changes, and take appropriate steps based on the supplied child view and position(Here, we updating the label with the text for that position).

The second parameter to our ArrayAdapter is android. R. layout. simple_list_item_1 which controls the look of the row.

Android List View — Multiple Selection

There may be occasions when you will want list that tracks a user’s selection, or perhaps multiple selections. ListView will be able to handle that too, however it requires a couple of further changes.

Very first, you will have to call setChoiceMode() by providing either CHOICE_MODE_SINGLE for single selection or CHOICE_MODE_MULTIPLE for multiple selection as the value. By using the getListView() You can get your ListView through ListActivity.

Then you will have to make use of either android.R.layout.simple_list_item_single_choice for single-choice or android.R.layout.simple_list_item_multiple_choice for multiple-choice lists, correspondingly in your ArrayAdapter.

Creating Layout for ListView

main.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"
    android:orientation="vertical" >
    <TextView
        android:id="@+id/selection"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
    <ListView
        android:id="@android:id/list"
    	android:layout_width="fill_parent"
    	android:layout_height="fill_parent"
    	android:drawSelectorOnTop="false"
    	android:choiceMode="multipleChoice"/>
</LinearLayout>

Java code to configure the list

ListViewActivity.java

package com.vimaltuts.android.listview;
import java.util.ArrayList;
import android.app.Activity;
import android.app.ListActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class ListViewActivity extends ListActivity {
    /** Called when the activity is first created. */
	private TextView selection;
	String str="";
	private static final String[] items={"Android","Bluetooth","Chrome","Docs","Email",
		"Facebook","Google","Hungary","Iphone","Korea","Machintosh",
		"Nokia","Orkut","Picasa","Singapore","Turkey","Windows","Youtube"};
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        setListAdapter(new ArrayAdapter(this,android.R.layout.simple_list_item_multiple_choice,items));
        selection=(TextView)findViewById(R.id.selection);
    }
    public void onListItemClick(ListView parent,View v,int position,long id){
    	str+=" "+items[position];
    	selection.setText(str);
    }
}

getCheckedItemPositions() — To find out which items the user checked on our ListView,
setItemChecked() — To check (or un-check) a specific entry ourselves.

In this Android List View Tutorial we have seen about the ListView. In the next tutorial we will see about the Android Spinner Control Example.

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