Android Application Development Cookbook: 93 Recipes for Building Winning Apps

import android.view.View;
import android.widget.CheckBox;
import android.widget.Toast;
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Figure 2-7 
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Recipe 2.4 using checkBoxes
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51
//---CheckBox---
CheckBox checkBox = (CheckBox) findViewById(R.id.chkAutosave);
checkBox.setOnClickListener(new View.OnClickListener() 
{
public void onClick(View v) {
if (((CheckBox)v).isChecked()) 
Toast.makeText(getBaseContext(), 
"CheckBox is checked", 
Toast.LENGTH_LONG).show();
else
Toast.makeText(getBaseContext(), 
"CheckBox is unchecked", 
Toast.LENGTH_LONG).show();
}
});
}
}
To determine the state of a checkbox, you need to listen to its 
onClick
event. The 
isChecked()
method of the checkbox returns 
true
if the checkbox is checked, or 
false
if it is not. Figure 2-8 
shows the 
Toast
class displaying the state of the Autosave checkbox.
Figure 2-8 
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52
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ChAPter 2
using Views to design the user interFAce
reCiPe 2.5 
iMPLeMenting A stAr rAting systeM
Android Versions
Level 1 and above
permissions
None
source code to download from Wrox.com
CheckBoxesRating.zip
The previous recipe introduced you to the checkbox, in particular the star checkbox. One popular 
use of the star checkbox is to implement a star rating system, whereby users tap on the stars to 
provide a rating for a particular item (such as user reviews for books, music, or venues). This recipe 
demonstrates how to implement this rating system.
solution
Assume you have the following code snippet in the 
activity_main.xml
file: 
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:id="@+id/ratings" >
android:id="@+id/star1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:tag="1" />
android:id="@+id/star2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:tag="2" />
android:id="@+id/star3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:tag="3" />
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