Could not find method in parent or ancestor context

Defining onClick in xml means you need to define it for a particular view here is ImageButton you can not have two arguments in that method.

Your error is also saying that Could not find method playPauseMusic(View) means compiler needs a public method with single parameter View, whereas you were having two parameters: View & ImageButton.

This is the reason why you where getting that error. Just remove one argument from the method and it will work.

Do it like this :

public class radio extends AppCompatActivity {    /** Called when the user touches the button */    public void playPauseMusic (View playPause) {        String url = "http://streamer.cci.utk.edu:8000/wutk-vorbis"; // your URL here        final MediaPlayer mediaPlayer = new MediaPlayer();        mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {            public void onPrepared(MediaPlayer mediaPlayer){                mediaPlayer.start();            }        });                if (mediaPlayer.isPlaying()) {             mediaPlayer.pause();             ((ImageButton)playPause).setImageResource(R.drawable.play1);        } else {            ((ImageButton)playPause).setImageResource(R.drawable.pause1);        }                mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);        mediaPlayer.setDataSource(url);        mediaPlayer.prepareAsync();    }    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_radio);    }}

One more thing writing android:onClick="playPauseMusic" means the method playPauseMusic will be called on Button click so you have already defined a button click so no need to define it inside the method by playPause.setOnClickListener so I have removed that code.

Your code possibly should start with:

@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_radio);}

You're specifying onClick in xml

android:onClick="playPauseMusic"

So, the method works, you've got inner onClicks too. If they are some views.

You gotta initialize and get it from the xml in code, for ex-

If you have ImageButton in xml, whose id is "playPause"

ImageButton playPause; //Declare it here if you wanna use it in all other places in the class or outside of your class@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_radio);    playPause = (ImageButton)findViewById(R.id.playPause);    playPause.setOnClickListener(new View.OnClickListener(){        public void onClick(View view) {           //OnCLick Stuff        }    });}

In Your case, you've got onClick attribute in xml and another onCLick in code. You Use one.

The question is already answered but I hope this will help someone like me in the future. I was having this error:

E/AndroidRuntime: FATAL EXCEPTION: main    Process: com.example.test1, PID: 6892    java.lang.IllegalStateException: Could not find method btnClickStartThread(View) in a parent or ancestor Context for android:onClick attribute defined on view class com.google.android.material.button.MaterialButton with id 'btnStartThread1'        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.resolveMethod(AppCompatViewInflater.java:447)        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:405)

After struggling a lot I got it fixed by going to layouts and I realized I had two layouts:

1. activity_main.xml
2. activity_main.xml (v21)

My changes were just reflecting on one and the app was loading other version of layout.

As suggested hereAndroid Studio not deploying changes to app