问根据是否第一次打开应用程序，如何显示不同的内容？

EN

@Override
protected void onResume() {
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
    // By default assume "true", which means this is the first launch.
    if (prefs.getBoolean("firstLaunch", true)) {
        // Start Activity B and finish myself.
        Intent i = new Intent(getApplicationContext(), ActivityB.class);
        startActivity(i);
        finish();
    }
}

// Do it after you've initialized everything, so Activity A can be launched:
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this)
SharedPreferences.Editor editor = prefs.edit();
// Set "fistLaunch" to "false", so Activity A will start next time.
editor.putBoolean("firstLaunch", false);
editor.commit();

SharedPreferences preferences = getSharedPreferences("prefName", MODE_PRIVATE);
if(!preferences.getBoolean("isFirstRun", false)) {
    // This mean App Launch First Time
    SharedPreferences preferences = getSharedPreferences("prefName", MODE_PRIVATE);
    SharedPreferences.Editor edit= preferences.edit();

    edit.putBoolean("isFirstRun", true);
    edit.commit();
    // Open the B Activity
} else {
    // This mean App Launch Second or third ... time and start the A Activity
}