Hello Everyone! I am a begginer in Java for Android development. I am reading a book called "Android Application Development for Dummies". In chapter 5 of the book, the following code snippet is given which is not
working. I am simply not able to get the app to display on the android emulator and work correctly. Can someone please help me know what I'm doing wrong within the code? Enter code here... package helloandroid.android.dummies.com.silentmodetoggle; import android.support.v7.app.AppCompatActivity; import android.graphics.drawable.Drawable; import android.media.AudioManager; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.ImageView; public class MainActivity extends AppCompatActivity { private AudioManager mAudioManager; private boolean mPhoneIsSilent; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); setButtonClickListener(); mAudioManager = (AudioManager) getSystemService(AUDIO_SERVICE); checkIfPhoneIsSilent(); setButtonClickListener(); } private void setButtonClickListener() { Button toggleButton = (Button) findViewById(R.id.toggleButton); toggleButton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { if (mPhoneIsSilent) { //Change back to silent mode mAudioManager .setRingerMode(AudioManager.RINGER_MODE_NORMAL); mPhoneIsSilent = false; } else { // Change to silent mode mAudioManager .setRingerMode(AudioManager.RINGER_MODE_SILENT); mPhoneIsSilent = true; } // Now toggle the UI again toggleUI(); } }); } /** * Checks to see if the phone is currently in silent mode */ private void checkIfPhoneIsSilent() { int ringerMode = mAudioManager.getRingerMode(); if (ringerMode == AudioManager.RINGER_MODE_SILENT) { mPhoneIsSilent = true; } else { mPhoneIsSilent = false; } } /** * Toggles the UI images from silent to normal and vice versa */ private void toggleUI() { ImageView imageView = (ImageView) findViewById(R.id.phone_icon); Drawable newPhoneImage; if (mPhoneIsSilent) { newPhoneImage = getResources(drawable.phone_silent } else { newPhoneImage = getResources(drawable.phone_on); } imageView.setImageDrawable(newPhoneImage); } @Override protected void onResume() { super.onResume(); checkIfPhoneIsSilent(); toggleUI(); } } All help is appreciated. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to android-developers+unsubscr...@googlegroups.com. To post to this group, send email to android-developers@googlegroups.com. Visit this group at https://groups.google.com/group/android-developers. To view this discussion on the web visit https://groups.google.com/d/msgid/android-developers/114b34aa-27f0-490b-bcd8-378a740bfd1e%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.