获取App包名versioncode和versionname
经常在应用中看到版本1.0.3类似的一串数据，这些数据怎么获取呢？
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
PackageManager manager = getPackageManager(); //获取PackageManager实例
PackageInfo info = manager.getPackageInfo(getPackageName(), 0); //获取包名，返回0则未获取到
String versionName = info.versionName; //通过包名获取versionname和versioncode
int versioncode = info.versionCode;
} catch (Exception e) {
}
}
}
