Hướng dẫn tạo menu trong Android

Hướng dẫn tạo menu trong Android

@2011 Mihail L Sichitiu 1

Android

Introduction

GUI Menu

@2011 Mihail L Sichitiu 2

Goal

options/sub/context menus

<option menu> <sub-menu> <context menu>

Automatically fill “Hi!”

in the EditText Plus menu will

also open a sub-menu

Display

messages when

a menu clicked

Menu Composition

Plus

Home

Pre

Next

<option menu>

Sub1 Sub2

Hi Hola

Hello

<sub-menu>

<context menu from EditText>

Long press

in EditText

@2011 Mihail L Sichitiu 4

Create HelloMenu Project

 Create the two TextViews

and an EditText

 Create “ menu ” folder in

res/

 Create menu.xml in

res/menu/ (New > Other >

Android XML File)

 Create context_menu.xml

in res/menu/

<?xml version="1.0" encoding="utf-8"?>

<menu

xmlns:android="http://schemas.android.com/apk/res/android">

<item android:id="@+id/menuItemPlus" android:title="@string/plus"

android:icon="@drawable/plus" >

<menu>

<item android:id="@+id/menuItemSub1" android:title="@string/sub1"></item>

<item android:id="@+id/menuItemSub2" android:title="@string/sub2"></item>

</menu>

</item>

<item android:icon="@drawable/home" android:id="@+id/menuItemHome"

android:title="@string/home"></item>

<item android:icon="@drawable/pre" android:id="@+id/menuItemPre"

android:title="@string/pre"></item>

<item android:icon="@drawable/next" android:id="@+id/menuItemNext"

android:title="@string/next"></item>

</menu>

Sub-menu items

Option menu items

 Define Option menu and sub-menu

@2011 Mihail L Sichitiu 6

res/menu/context.xml

<?xml version="1.0" encoding="utf-8"?>

<menu

xmlns:android="http://schemas.android.com/apk/res/android">

<item android:id="@+id/menuItemHi" android:title="@string/hi_msg"></item>

<item android:id="@+id/menuItemHola" android:title="@string/hola_msg"></item>

<item android:id="@+id/menuItemHello" android:title="@string/hello_msg"></item>

</menu>

 Define context menu for EditText

<?xml version="1.0" encoding="utf-8"?>

<resources>

<string name="hello">Click Menu Button ! </string>

<string name="app_name">Android Menu Example</string>

<string name="plus">Plus</string>

<string name="pre">Pre</string>

<string name="next">Next</string>

<string name="home">Home</string>

<string name="sub1">Sub1</string>

<string name="sub2">Sub2</string>

<string name="hi_msg">Hi !</string>

<string name="hola_msg">Hola !</string>

<string name="hello_msg">Hello !</string>

</resources>

 Define constant strings used in the application

@2011 Mihail L Sichitiu 8

icons

 Place icons used in menu.xml in res/drawable/

icons

 Download icons at:

http://www4.ncsu.edu/~mlsichit/UCAB/resources.html

Inflating a option menu

resource

 Inflating a menu resource (menu.xml) by adding

onCreateOptionsMenu(Menu menu) in the main Activity.

 Menu items in menu.xml will appear when the user touches the

MENU button

public boolean onCreateOptionsMenu(Menu menu) {

MenuInflater inflater = getMenuInflater();

inflater.inflate(R.menu.menu, menu);

return true;

}

public boolean onCreateOptionsMenu (Menu menu) {

MenuInflater inflater = getMenuInflater();

inflater.inflate(R.menu menu , menu);

return true;

}

@2011 Mihail L Sichitiu 10

Response to user action

onOptionsItemSelected(Menu menu) in the

main Activity.

@Override

public boolean onOptionsItemSelected(MenuItem item) {

switch (item.getItemId()) {

case R.id.menuItemPlus:

Toast.makeText(this, "Plus Button Clicked !", Toast.LENGTH_SHORT).show();

Log.i(TAG,"menuItemPlus");

return true;

:

:

case R.id.menuItemNext:

Toast.makeText(this, "Next Button Clicked !", Toast.LENGTH_SHORT).show();

Log.i(TAG,"menuItemNext");

return true;

}

return false;

}

@Override

public boolean onOptionsItemSelected(MenuItem item) {

switch (item.getItemId()) {

case R.id.menuItemPlus:

Toast.makeText(this, "Plus Button Clicked !", Toast.LENGTH_SHORT).show();

Log.i(TAG,"menuItemPlus");

return true;

:

:

case R.id.menuItemNext:

Toast.makeText(this, "Next Button Clicked !", Toast.LENGTH_SHORT).show();

Log.i(TAG,"menuItemNext");

return true;

}

return false;

}

Register View for a context

menu

passing it a View (an EditText in this example)

you assign it a context menu

it displays a context menu.

public class AndroidMenuExampleActivity extends Activity {

private EditText mOutEditText;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

mOutEditText = (EditText) findViewById(R.id.editText);

registerForContextMenu(mOutEditText);

}

:

:

public class AndroidMenuExampleActivity extends Activity {

private EditText mOutEditText ;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

mOutEditText = (EditText) findViewById(R.id.editText);

registerForContextMenu(mOutEditText);

}

:

:

@2011 Mihail L Sichitiu 12

Define context menu’s

appearance

By overriding the activity's context menu create callback method,

onCreateContextMenu().

@Override

public void onCreateContextMenu(ContextMenu menu, View v,

ContextMenuInfo menuInfo) {

super.onCreateContextMenu(menu, v, menuInfo);

MenuInflater inflater = getMenuInflater();

inflater.inflate(R.menu.context_menu, menu);

}

@Override

public void onCreateContextMenu(ContextMenu menu, View v,

ContextMenuInfo menuInfo) {

super.onCreateContextMenu(menu, v, menuInfo);

MenuInflater inflater = getMenuInflater();

inflater.inflate(R.menu.context_menu, menu);

}

Define context menu’s

behavior

method for context menu , onContextItemSelected().

@Override

public boolean onContextItemSelected(MenuItem item) {

Log.i(TAG,"ContextItem selected");

AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();

switch (item.getItemId()) {

case R.id.menuItemHi:

mOutEditText.setText( this.getResources().getText( R.string.hi_msg) );

return true;

case R.id.menuItemHola:

:

:

default:

return super.onContextItemSelected(item);

}

}

@Override

public boolean onContextItemSelected(MenuItem item) {

Log.i(TAG,"ContextItem selected");

AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();

switch (item.getItemId()) {

case R.id.menuItemHi:

mOutEditText.setText( this.getResources().getText( R.string.hi_msg) );

return true;

case R.id.menuItemHola:

:

default:

return super.onContextItemSelected(item);

}

}