public class MainActivity extends ActionBarActivity {     private TextView mTextView;    @Override    protected void onCreate(Bundle savedInstanceState) {        // TODO Auto-generated method stub        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //获取当前项目版本号        mTextView = (TextView) findViewById(R.id.textView1);        try {            getVersionName();        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        //Android系统版本信息    String    Model_VERSION="Android系统版本信息: " + android.os.Build.MODEL + ",API "         + android.os.Build.VERSION.SDK + ",Android "         + android.os.Build.VERSION.RELEASE;    //显示信息        try {            mTextView.setText("当前程序版本: "+ getVersionName()+"\n"+Model_VERSION );        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }      private String getVersionName() throws Exception       {               // 获取packagemanager的实例               PackageManager packageManager = getPackageManager();               // getPackageName()是你当前类的包名，0代表是获取版本信息               PackageInfo packInfo = packageManager.getPackageInfo(getPackageName(),0);               String version = packInfo.versionName;               return version;       }
}