是否有音频在播放? (在Android)

Is Any Audio Is Playing? (In Android)

我的应用程序中有两个活动,第一个 (MainActivity.java) 有一个按钮可以调用 activity 两个 (player.java),第二个有音频和一个停止按钮。

所以我面临的主要问题是..

当我从一个点击开始第二个 activity 时,它会转到另一个 activity, 正如我编程的那样,它会自动启动音频(我希望它自动启动)我按下停止音频停止...然后再次返回 MainActivity 调用第二个 activity (player.java) 它工作正常...再次它可以正确启动音频...当我向后按时一切正常,音频继续播放...(这就是我想要的)

但是,如果在不停止音频的情况下按返回键,并再次开始第二个 activity (player.java),它会在不停止第一个的情况下再次启动音频...并且同一首曲目会播放两个次...

我只想一次播放一首曲目...如果正在播放任何其他音频,请停止播放,当我再次播放时 activity。

这是我的代码...

MainActivity.java

package com.test.myapp;

import android.app.*;
import android.os.*;
import android.content.*;
import android.widget.*;
import android.view.*;

public class MainActivity extends Activity {
  Button btn;

    @Override
    public void onCreate(Bundle savedIntanceState) {
        super.onCreate(savedIntanceState);
        setContentView(R.layout.activity_main);

        btn = (Button) findViewById(R.id.button);

        public void clicked(View v){
            if (v.getId() == R.id.button){
              Intent i = new Intent (MainActivity.this, player.class);
              startActivity(i);
            }
        }
    }
}

player.java

package com.test.myapp;

import android.app.*;
import android.os.*;
import android.content.*;
import android.widget.*;
import android.view.*;
import android.media.*;

public class player extends Activity {
  Button stop;
  MediaPlayer audio;

    @Override
    public void onCreate(Bundle savedIntanceState) {
        super.onCreate(savedIntanceState);
        setContentView(R.layout.player);

        stop= (Button) findViewById(R.id.stop);
        audio = MediaPlayer.create(getBaseContext(), R.raw.myAudio);
        audio.start();

        public void stop(View v){
            if (v.getId() == R.id.stop){
                audio.stop();
                audio = MediaPlayer.create(getBaseContext(), R.raw.myAudio);
            }
        }
    }
}

将您的 MediaPlayer 对象设为静态并检查 Mediaplayer isPlaying()。尝试

public class player extends Activity {
    Button stop;
    static MediaPlayer audio;

    @Override
    public void onCreate(Bundle savedIntanceState) {
        super.onCreate(savedIntanceState);
        setContentView(R.layout.activity_player);

        stop = (Button) findViewById(R.id.stop);
        stop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                audio.stop();
            }
        });

        if(audio == null) {
            audio = MediaPlayer.create(getBaseContext(), R.raw.myaudio);
            audio.start();
        } else {
            if(audio.isPlaying()) {
                audio.stop();
                audio = MediaPlayer.create(getBaseContext(), R.raw.myaudio);
                audio.start();
            } else {
                audio = MediaPlayer.create(getBaseContext(), R.raw.myaudio);
                audio.start();
            }
        }
    }

}