In this example we shall show you how to use Preferences with Android. This functionality is used for storing user’s preferences and using them for example when the application starts.
For using the Preferences framework the following steps must be followed:
- Create a class that extends PreferenceActivity (here called QuickPrefsActivity)
- Use the addPreferencesFromResource method in order to read the config from a resource file
- Create the XML resource file based on the PreferenceScreen class
- Create another class extending Activity (here called ShowSettingsActivity)
- Use the PreferenceManager in order to retrieve the SharedPreferences object
These are demonstrated in the code snippet(s) below:
package com.javacodegeeks.android.preferences;
import android.content.Intent;
import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.view.Menu;
import android.view.MenuItem;
public class QuickPrefsActivity extends PreferenceActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preferences);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
menu.add(Menu.NONE, 0, 0, "Show current settings");
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case 0:
startActivity(new Intent(this, ShowSettingsActivity.class));
return true;
}
return false;
}
}<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory
android:title="First Category"
android:key="first_category">
<CheckBoxPreference
android:key="perform_updates"
android:summary="Enable or disable data updates"
android:title="Enable updates"
android:defaultValue="true"
/>
<ListPreference
android:key="updates_interval"
android:title="Updates interval"
android:summary="Define how often updates will be performed"
android:defaultValue="1000"
android:entries="@array/updateInterval"
android:entryValues="@array/updateIntervalValues"
android:dependency="perform_updates"
/>
</PreferenceCategory>
<PreferenceCategory
android:title="Second Category"
android:key="second_category">
<EditTextPreference
android:key="welcome_message"
android:title="Welcome Message"
android:summary="Define the Welcome message to be shown"
android:dialogTitle="Welcome Message"
android:dialogMessage="Provide a message"
android:defaultValue="Default welcome message" />
</PreferenceCategory>
</PreferenceScreen><?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="updateInterval">
<item name="1000">Every 1 second</item>
<item name="5000">Every 5 seconds</item>
<item name="30000">Every 30 seconds</item>
<item name="60000">Every 1 minute</item>
<item name="300000">Every 5 minutes</item>
</string-array>
<string-array name="updateIntervalValues">
<item name="1000">1000</item>
<item name="5000">5000</item>
<item name="30000">30000</item>
<item name="60000">60000</item>
<item name="300000">300000</item>
</string-array>
</resources><?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.javacodegeeks.android.preferences"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".QuickPrefsActivity" android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".ShowSettingsActivity" />
</application>
<uses-sdk android:minSdkVersion="3" />
</manifest>package com.javacodegeeks.android.preferences;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.widget.TextView;
public class ShowSettingsActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.show_settings_layout);
SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);
StringBuilder builder = new StringBuilder();
builder.append("n" + sharedPrefs.getBoolean("perform_updates", false));
builder.append("n" + sharedPrefs.getString("updates_interval", "-1"));
builder.append("n" + sharedPrefs.getString("welcome_message", "NULL"));
TextView settingsTextView = (TextView) findViewById(R.id.settings_text_view);
settingsTextView.setText(builder.toString());
}
}<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:id="@+id/settings_text_view"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>
This was an example of how to use Preferences with Android.
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