当活动失去焦点时(主页或屏幕熄灭时),媒体播放器会暂停音乐

Question

当按下主页按钮或屏幕关闭时,媒体播放器会停止音乐....即使活动失去焦点,我也希望音乐继续播放....但我希望音乐暂停以接听来电以及用户是否暂停音乐. ......当通过后退按钮关闭活动时,音乐应该停止

这是我的代码示例:

package com.example.acer.aartisangrah;

import android.content.Context;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.telephony.PhoneStateListener;
import android.telephony.TelephonyManager;
import android.text.Html;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Toast;

public class ekdanta extends AppCompatActivity implements Runnable, View.OnClickListener,SeekBar.OnSeekBarChangeListener {
TextView tv4;
Button b9, b10,but19;
int count = 0;
MediaPlayer play;
SeekBar seek_bar;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_ekdanta);
    tv4 = (TextView) findViewById(R.id.textView9);
    tv4.setTextSize(18);
    tv4.setText(Html.fromHtml(getString(R.string.thirteen)));
    b9 = (Button) findViewById(R.id.b9);
    b10 = (Button) findViewById(R.id.b10);
    seek_bar = (SeekBar) findViewById(R.id.seekBar);
    seek_bar.setOnSeekBarChangeListener(this);
    seek_bar.setEnabled(false);
    but19 = (Button) findViewById(R.id.button19);
    but19.setOnClickListener(this);
    TelephonyManager mTelephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
    mTelephonyManager.listen(mPhoneListener, PhoneStateListener.LISTEN_CALL_STATE);
}
private final PhoneStateListener mPhoneListener=new PhoneStateListener(){
    public void onCallStateChanged(int state, String incomingNumber) {
        super.onCallStateChanged(state, incomingNumber);

        // Call receive state
        if (state != TelephonyManager.CALL_STATE_IDLE) {
            if ((play!= null) && (play.isPlaying()))
            {
                play.pause();
                but19.setBackgroundResource(R.drawable.play);
            }
        }
    }
};

public void run() {
    int currentPosition = play.getCurrentPosition();
    final int total = play.getDuration();
    while (play != null && currentPosition < total) {
        try {
            Thread.sleep(1000);
            currentPosition = play.getCurrentPosition();
        } catch (InterruptedException e) {
            return;
        } catch (Exception e) {
            return;
        }
        seek_bar.setProgress(currentPosition);
    }
}
public void onClick(View v) {
    if (v.equals(but19)) {
        if (play == null) {
            play = MediaPlayer.create(getApplicationContext(), R.raw.ekadanta);
            seek_bar.setEnabled(true);
        }
        if (play.isPlaying()) {
            play.pause();
            but19.setBackgroundResource(R.drawable.play);
        } else {
            play.start();
            but19.setBackgroundResource(R.drawable.pause);
            seek_bar.setMax(play.getDuration());
            new Thread(this).start();
        }
    }
    play.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mp) {
            play.seekTo(0);
            but19.setBackgroundResource(R.drawable.play);
        }
    });
}

@Override
protected void onPause()
{
    super.onPause();
}

@Override
protected void onDestroy()
{
    super.onDestroy();
    play.release();
}

@Override
public void onProgressChanged(SeekBar seek_bar, int progress, boolean fromUser) {
    try{
        if(play.isPlaying()||play!=null){
            if (fromUser)
                play.seekTo(progress);
        }
        else if(play==null){
            Toast.makeText(getApplicationContext(),"First Play", Toast.LENGTH_SHORT).show();
            seek_bar.setProgress(0);
        }
    }
    catch(Exception e){
        Log.e("seek bar",""+e);
        seek_bar.setEnabled(false);
    }
}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {

}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {

}

public void increase(View inc) {
    count++;
    if (count == 1) {
        tv4.setTextSize(22);
    } else if (count == 2) {
        tv4.setTextSize(30);
    } else if (count >= 3) {
        count = 3;
        tv4.setTextSize(40);
    }
}

public void decrease(View dec) {
    count--;
    if (count <= 0) {
        tv4.setTextSize(18);
        count = 0;
    }
    if (count == 1) {
        tv4.setTextSize(22);
    } else if (count == 2) {
        tv4.setTextSize(30);
    } else if (count == 3) {
        tv4.setTextSize(40);
    }
}
}

编辑

使用此代码进行活动后...此活动无法在某些设备上打开...应用程序只是自行关闭....请帮助!没有此代码的其他活动也很好......

Answer 1

首先,您有以下代码

@Override
protected void onPause()
{
    super.onPause();
    if ((play!= null) && (play.isPlaying()))
    {
        play.pause();
    }
}

每次活动进入后台(失去焦点)或用户关闭时执行onPause方法.所以你的第一步就是从你故意调用的onPause方法中删除这段代码play.pause().

您应该覆盖该onBackPressed()方法并执行与您正在执行的操作类似的操作play.stop()

请在此处查看,特别是在执行清理部分,其中显示以下内容

MediaPlayer对象可能会消耗大量的系统资源,因此您应该只在需要时保留它,并在完成后调用release().显式调用此清理方法而不是依赖系统垃圾收集非常重要,因为垃圾收集器可能需要一些时间才能收回MediaPlayer

请务必查看该指南.