MENU in Android
Menus are a common user interface component in many types of
applications. To provide a familiar and consistent user experience, you should
use the Menu APIs to present user actions and other options in your activities.
Beginning with Android 3.0 (API level 11), Android-powered
devices are no longer required to provide a dedicated Menu button.
With this change, Android apps should migrate away from a dependence on the
traditional 6-item menu panel and instead provide an action bar to present
common user actions.
To
define the menu, create an XML file inside your project's res/menu/ directory and build the menu
with the following elements:
<menu>
Defines
a Menu, which is a container for menu items. A <menu> element
must be the root node for the file and can hold one or more <item> and <group> elements.
<item>
Creates
a MenuItem, which represents a single item in a menu. This element may contain
a nested <menu>element in
order to create a submenu.
<group>
An
optional, invisible container for <item> elements.
It allows you to categorize menu items so they share properties such as active
state and visibility.
Where
the items in your options menu appear on the screen depends on the version for
which you've developed your application:
If you've developed your application for Android 2.3.x
(API level 10) or lower, the contents of your options menu appear at the
bottom of the screen when the user presses the Menu button.
When opened, the first visible portion is the icon menu, which holds up to six
menu items. If your menu includes more than six items, Android places the sixth
item and the rest into the overflow menu, which the user can open by
selecting More.
If you've developed your application for Android 3.0 (API
level 11) and higher, items from the options menu are available in
the action
bar. By default, the system places all items in the action
overflow, which the user can reveal with the action overflow icon on the right
side of the action bar (or by pressing the device Menu button,
if available). To enable quick access to important actions, you can promote a
few items to appear in the action bar by adding android:showAsAction="ifRoom" to
the corresponding <item> elements.
In this tutorial we are creating a
simple menu with 6 menu items. On clicking on single menu item a simple Toast
message will be shown.
1. Create
a new project File ⇒ New ⇒ Android Project and
give activity name asAndroidMenusActivity.
2. Now create an XML file under res/layout folder and name it as menu.xml.
3. Open menu.xml file and type following code. In the following code we are creating a single menu with 6 menu items. Each menu item has an icon and title for display the label under menu icon. Also we have id for each menu item to identify uniquely.
2. Now create an XML file under res/layout folder and name it as menu.xml.
3. Open menu.xml file and type following code. In the following code we are creating a single menu with 6 menu items. Each menu item has an icon and title for display the label under menu icon. Also we have id for each menu item to identify uniquely.
<?xml
version="1.0" encoding="utf-8"?>
<menu
xmlns:android="http://schemas.android.com/apk/res/android">
<!-- Single menu item
Set id, icon and Title for each menu item
-->
<item
android:id="@+id/menu_bookmark"
android:icon="@drawable/icon_bookmark"
android:title="Bookmark"
/>
<item
android:id="@+id/menu_save"
android:icon="@drawable/icon_save"
android:title="Save" />
<item
android:id="@+id/menu_search"
android:icon="@drawable/icon_search"
android:title="Search"
/>
<item
android:id="@+id/menu_share"
android:icon="@drawable/icon_share"
android:title="Share" />
<item
android:id="@+id/menu_delete"
android:icon="@drawable/icon_delete"
android:title="Delete"
/>
<item
android:id="@+id/menu_preferences"
android:icon="@drawable/icon_preferences"
android:title="Preferences"
/>
</menu>
4.
Now open your main Activity class file (AndroidMenusActivity.java)
and type following code. In the following code each menu item is identified by
its ID in switch case statement.
import
android.app.Activity;
import android.os.Bundle;
import
android.view.Menu;
import
android.view.MenuInflater;
import
android.view.MenuItem;
import
android.widget.Toast;
public
class AndroidMenusActivity extends Activity {
@Override
public void onCreate(Bundle
savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
// Initiating Menu XML file (menu.xml)
@Override
public boolean onCreateOptionsMenu(Menu
menu)
{
MenuInflater menuInflater =
getMenuInflater();
menuInflater.inflate(R.layout.menu,
menu);
return true;
}
/**
* Event Handling for Individual menu item
selected
* Identify single menu item by it's id
* */
@Override
public boolean
onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case R.id.menu_bookmark:
//
Single menu item is selected do something
//
Ex: launching new activity/screen or show alert message
Toast.makeText(AndroidMenusActivity.this, "Bookmark is
Selected", Toast.LENGTH_SHORT).show();
return true;
case R.id.menu_save:
Toast.makeText(AndroidMenusActivity.this,
"Save is Selected", Toast.LENGTH_SHORT).show();
return true;
case R.id.menu_search:
Toast.makeText(AndroidMenusActivity.this,
"Search is Selected", Toast.LENGTH_SHORT).show();
return true;
case R.id.menu_share:
Toast.makeText(AndroidMenusActivity.this,
"Share is Selected", Toast.LENGTH_SHORT).show();
return true;
case R.id.menu_delete:
Toast.makeText(AndroidMenusActivity.this,
"Delete is Selected", Toast.LENGTH_SHORT).show();
return true;
case R.id.menu_preferences:
Toast.makeText(AndroidMenusActivity.this,
"Preferences is Selected", Toast.LENGTH_SHORT).show();
return true;
default:
return
super.onOptionsItemSelected(item);
}
}
}
5.
Finally run your project by right
clicking on your project folder ⇒ Run As ⇒ 1 Android Application to
test your application. On Android Emulator click on Menu Button to launch menu.
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