實現獲取應用程式的版本號和阪本名,通過獲取包管理器開始;步驟如下:
程式如下

public class MainActivity extends AppCompatActivity {
    Context mContext;
    private TextView mMVersionCode;//版本code
    private TextView mMVersionName;//版本名


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mContext = this
 
;
        initView();//初始化控制元件
    }

    private void initView() {
        mMVersionCode = (TextView) findViewById(R.id.tv_versinonCode);
        mMVersionName = (TextView) findViewById(R.id.tv_versionName);
    }
    //點選按鈕實現獲取版本號和阪本名字
    public void getVersion(View v)
     {
         //1,獲取包 管理器
        PackageManager packageManager =  mContext.getPackageManager();
        //2,通過上下文獲取包名
 

        String packageName = mContext.getPackageName();

        try {
        //3,獲取包的資訊
            PackageInfo packageInfo = packageManager.getPackageInfo(packageName, 0);
            //4,獲取版本號
            int versionCode = packageInfo.versionCode;
            //5,獲取版本名
            String versionName = packageInfo.versionName;
            //給textview設定對應的值
 

            mMVersionCode.setText("版本號為:"+versionCode);
            mMVersionName.setText("版本名為:"+versionName);
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
    }
}