バージョンを表示するView Widget

strings.xml

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

    <string name="version">Version: %s</string>

</resources>

VersionView.java

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.util.AttributeSet;
import android.widget.TextView;

public class VersionView extends TextView {

    public VersionView(Context context) {
        this(context, null);
    }

    public VersionView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public VersionView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        PackageManager packageManager = context.getPackageManager();
        String version = null;
        try {
            PackageInfo packageInfo = packageManager.getPackageInfo(
                    context.getPackageName(), PackageManager.GET_ACTIVITIES);
            version = packageInfo.versionName;
        } catch (NameNotFoundException e) {
            e.printStackTrace();
        }

        this.setText(context.getString(R.string.version, version));
    }

}