Android App code opened by package name

When the launcher is used, the user clicks the apk icon and needs to open this apk. There are two ways to start this apk:

First: Know the package name of the apk and its main Activity

// Help private ComponentName help_set; private final static String help_set_pack = "cn. abc. help "; private final static String help_set_name =" cn. abc. help. mainActivity ";/*** start an app * com -- ComponentName object, package name containing apk and main Activity name * param -- parameters to be passed to apk */private void startApp (ComponentName com, String param) {if (com! = Null) {PackageInfo packageInfo; try {packageInfo = getPackageManager (). getPackageInfo (com. getPackageName (), 0);} catch (NameNotFoundException e) {packageInfo = null; Toast. makeText (this, "not installed", Toast. LENGTH_SHORT ). show (); e. printStackTrace ();} try {Intent intent = new Intent (); intent. setFlags (Intent. FLAG_ACTIVITY_NEW_TASK); intent. setComponent (com); if (param! = Null) {Bundle bundle = new Bundle (); // create a Bundle object bundle. putString ("flag", param); // load data intent. putExtras (bundle); // insert Bundle into Intent} startActivity (intent);} catch (Exception e) {Toast. makeText (this, "Startup exception", Toast. LENGTH_SHORT ). show ();}}}

Second: only know the package name of the apk. This method is the most commonly used. After all, the apk to be started is not necessarily written by ourselves.

/** Start an app */public void startAPP (String appPackageName) {try {Intent intent = this. getPackageManager (). getLaunchIntentForPackage (appPackageName); startActivity (intent);} catch (Exception e) {Toast. makeText (this, "not installed", Toast. LENGTH_LONG ). show ();}}

In combination, the code of the second method is much simpler and more practical!