PREFERENCE ACTIVITY

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Preference Activity In Android Example

PreferenceActivity  is the base class for an activity to show a hierarchy of preferences to the user.
It is generally used for saving the setting/preference of  User. Android provides excellent framework to save and mange the User preferences.
We just need to use the class and specify some resources , and it automatically creates GUI for that itself. 

PreferenceActivity  Example In Android:

In this example I have created a Page/Screen with user can save his password, and other choices/details.

Steps:

1: Create xml resource for Preference:  create an xml file inside xml folder (if xml folder is not there inside res folder, createxml folder inside res folder. In the example I have created user_settings.xml file inside xml folder.

2: Create a Class which extends PreferenceActivity class , and inflate the created xml using addPreferencesFromResource() method.

3: Call/Start the PreferenceActivity (created in 2nd steps) from where you want. In the example I have called from MainActivity using startActivityForResult()   method.

Now lets go Step by Step:

Step1: Create XML resource inside xml folder: 

user_settings.xml

This file defines user interface for setting page. We have created 3 different categories here. 

1: EditTextPreference  is used to define an editable text property. In this example used this field to enter the Password
2:CheckBoxPreference  allows you to define a boolean value in preference screen.
3: ListPreference   display choices from which user can select one.. In this examplewe have used ListPreference to choose the frequency when user should be reminded.


<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >

    <PreferenceCategory android:title="Settings" >
        <EditTextPreference
                android:title="Password"
                android:summary="Set Your Password"
                android:key="prefUserPassword"/>
    </PreferenceCategory>
     
    <PreferenceCategory android:title="Security Settings" >
        <CheckBoxPreference
            android:defaultValue="false"
            android:key="prefLockScreen"
            android:summary="Lock The Screen With Password"
            android:title="Screen Lock" >
        </CheckBoxPreference>

        <ListPreference
            android:key="prefUpdateFrequency"
            android:title="Reminder for Updation"
            android:summary="Set Update Reminder Frequency"
            android:entries="@array/updateFrequency"
            android:entryValues="@array/updateFrequencyValues"
            />
    </PreferenceCategory>

</PreferenceScreen>

Since we have used arrays here, We need to define it inside array.xml file.
Create an arrays.xml file  inside values folder and write following

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="updateFrequency">
        <item name="1">Daily</item>
        <item name="7">Weekly</item>
        <item name="3">Yearly</item>
        <item name="0">Never(I will Myself) </item>
    </string-array>
    <string-array name="updateFrequencyValues">
        <item name="1">1</item>
        <item name="7">7</item>
        <item name="30">30</item>
        <item name="0">0</item>
    </string-array>
     
</resources>

2: Create a Class which extends PreferenceActivity class

public class UserSettingActivity extends PreferenceActivity 
{
             
             @Override
             public void onCreate(Bundle savedInstanceState) 
             {
                     super.onCreate(savedInstanceState);
                      // add the xml resource                     addPreferencesFromResource(R.xml.user_settings);
                     

             }

} 

3: Call/Start the PreferenceActivity.

We have called  UserSettingActivity from MainActivity

xml for MainActivity

main.xml   contains two things

1: Button: We start  UserSettingActivity when user clicks on this buttons.
2: TextView:   To show the User data like password etc.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#CCCCFF"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/buttonSettings"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="150dp"
        android:textSize="25dp"
        android:text="Settings" />

    <TextView
        android:id="@+id/textViewSettings"
        android:textSize="21dp"
        android:textColor="#0000FF"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_below="@+id/buttonSettings"
        android:layout_marginTop="66dp"
        android:text="No Settings"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

MainActivty

public class MainActivity extends Activity 
{
            private static final int SETTINGS_RESULT = 1;
            Button settingButton;

              @Override
              protected void onCreate(Bundle savedInstanceState)
              {
                        super.onCreate(savedInstanceState);
                        setContentView(R.layout.main);
                        
                        Button btnSettings=(Button)findViewById(R.id.buttonSettings);
                        // start the UserSettingActivity when user clicks on Button
                        btnSettings.setOnClickListener(new View.OnClickListener() {
                            
                            public void onClick(View v) {
                                // TODO Auto-generated method stub
                                Intent i = new Intent(getApplicationContext(), UserSettingActivity.class);
                                startActivityForResult(i, SETTINGS_RESULT);
                            }
                        });
              }



                @Override
                protected void onActivityResult(int requestCode, int resultCode, Intent data)
                {
                            super.onActivityResult(requestCode, resultCode, data);

                                if(requestCode==SETTINGS_RESULT)
                                {
                                    displayUserSettings();
                                }

                }

                
                private void displayUserSettings() 
                {
                        SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);

                        String  settings = "";

                        settings=settings+"Password: " + sharedPrefs.getString("prefUserPassword", "NOPASSWORD");

                        settings=settings+"\nRemind For Update:"+ sharedPrefs.getBoolean("prefLockScreen", false);

                        settings=settings+"\nUpdate Frequency: "
                                + sharedPrefs.getString("prefUpdateFrequency", "NOUPDATE");

                        TextView textViewSetting = (TextView) findViewById(R.id.textViewSettings);

                        textViewSetting.setText(settings);
                 }

}

How to fetch the User Saved data:

 sharedPrefs.getString("prefUserPassword", "NOPASSWORD");
we need to provide the key , that was given in xml ( android:key="prefUserPassword" in user_settings.xml file  )
We need to pass key as first argument and default value as second argumment. 

OUTPUT :-

                                                    

                                                     

                                                     

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