AboutActivity.java

package com.qiniu.qiniulab.activity;

import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.view.MenuItem;
import android.widget.TextView;

import com.qiniu.qiniulab.R;

public class AboutActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.about_activity);

        TextView versionTextView = (TextView) this
                .findViewById(R.id.version_number);
        String version = versionTextView.getText().toString();
        try {
            versionTextView.setText(version + this.getVersionName());
        } catch (Exception e) {
            // pass
        }
        // set action bar behavior
        ActionBar actionBar = this.getSupportActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                super.onBackPressed();
                return true;
        }
        return super.onOptionsItemSelected(item);
    }

    private String getVersionName() throws Exception {
        PackageManager packageManager = getPackageManager();
        PackageInfo packInfo = packageManager.getPackageInfo(getPackageName(),
                0);
        String version = packInfo.versionName;
        return version;
    }
}