Android APP reads version information in AndroidManifest. xml, androidmanifest. xml

Android APP reads version information in AndroidManifest. xml, androidmanifest. xml

The Android APP version information is stored at the top of the AndroidManifest. xml file. For example:

There are two attributes, "android: versionCode" and "android: versionName". versionCode is of the int type and is used by the program. Generally, this attribute is used for version control, versionName is of the String type and is displayed to users. For example, the current version is displayed on the page of the APP. In the new project, versionCode is 1 by default, and versionName is 1.0 by default.

Next we will use a program to read these two attributes.

The layout file code is as follows:

<? Xml version = "1.0" encoding = "UTF-8"?> <LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android" android: layout_width = "match_parent" android: layout_height = "match_parent" android: orientation = "vertical"> <TextView android: layout_width = "fill_parent" android: layout_height = "wrap_content" android: text = "APP version:"/> <TextView android: id = "@ + id/tvVersion" android: layout_width = "fill_parent" android: layout_height = "wrap_content"/> </LinearLayout>

The Activity code is as follows:

Package chengyujia. androidtest; import android. app. activity; import android. content. pm. packageInfo; import android. content. pm. packageManager; import android. content. pm. packageManager. nameNotFoundException; import android. OS. bundle; import android. widget. textView; public class VersionActivity extends Activity {private TextView tvVersion; @ Override protected void onCreate (Bundle savedInstanceState) {super. OnCreate (savedInstanceState); setContentView (R. layout. activity_version); tvVersion = (TextView) findViewById (R. id. tvVersion); showVersion ();} private void showVersion () {// you can directly call getPackageManager () in the Activity to obtain the PackageManager instance. PackageManager packageManager = getPackageManager (); // you can directly call getPackageName () in the Activity to obtain the full name of the installation package. String packageName = getPackageName (); // flags provides 10 options and their combinations. If you only get the version number, flags = 0 can be int flags = 0; PackageInfo packageInfo = null; try {// obtain AndroidManifest through packageInfo. information in xml. PackageInfo = packageManager. getPackageInfo (packageName, flags);} catch (NameNotFoundException e) {e. printStackTrace ();} if (packageInfo! = Null) {// here we get the version information. Int versionCode = packageInfo. versionCode; String versionName = packageInfo. versionName; tvVersion. setText ("versionCode =" + versionCode + "\ nversionName =" + versionName );}}}

Run the command to see the effect:

The default value is displayed. When a new version of our APP is released, you need. modify the two values in xml. versionCode is of the int type, which is generally auto-incrementing from 1. If the value is not of the int type, an error is returned. For example:

VersionName is of the String type, as long as it is a String, such:

Run the following command to view the details:

If you want to read the version information, write this. It's time to have dinner ^_^.