display your app's version in preferences screen

VersionPreference.java

package com.fletech.android.preference;

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.preference.Preference;
import android.util.AttributeSet;

/*
Author: Gavriel Fleischer <flocsy@gmail.com>

Use VersionPreference to display the compiled version of your app in your preferences activity.

res/xml/preferences.xml:

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    <com.fletech.android.preference.VersionPreference android:title="@string/pref_title_version" />
</PreferenceScreen>

res/values/strings.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="pref_title_version">Version</string>
</resources>

 */
public class VersionPreference extends Preference {
    public VersionPreference(Context context, AttributeSet attrs) {
        super(context, attrs);
        String versionName;
        final PackageManager packageManager = context.getPackageManager();
        if (packageManager != null) {
            try {
                PackageInfo packageInfo = packageManager.getPackageInfo(context.getPackageName(), 0);
                versionName = packageInfo.versionName;
            } catch (PackageManager.NameNotFoundException e) {
                versionName = null;
            }
            setSummary(versionName);
        }
    }
}