Question

我有简单的imageview应用程序，可以在后台播放音乐。然而，我的问题是当用户将设备侧向转换为横向模式时...第一首音乐（比如a），再次开始播放，首先播放的音乐也随之播放。我知道我对媒体播放器有一些问题，但我不知道它在我的代码中的确切位置...如何阻止这个问题....

Maainactivity.java

import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.Menu;

import android.view.MenuItem;
import android.widget.ShareActionProvider;

public class MainActivity extends Activity {

    MediaPlayer oursong;
    ViewPager viewPager;
    ImageAdapter adapter;

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

         oursong = MediaPlayer.create(MainActivity.this, R.raw.a);
         oursong.seekTo(0);
         oursong.start();

         viewPager = (ViewPager) findViewById(R.id.view_pager);
         adapter = new ImageAdapter(this);
         viewPager.setAdapter(adapter);


         viewPager.setOnPageChangeListener(MyViewPagerListener);
    }



    private int pos = 0;
    @Override
    protected void onPause() {
            super.onPause();

           if(oursong != null){
               pos = oursong.getCurrentPosition();
               oursong.release();
               oursong = null;
            }
    }

    @Override
    protected void onResume(){
          super.onResume();

         /*
          * This is the important part, basically since your releasing the song
          * in onPause() you are getting rid of its reference, in this case check
          * if your song is null then if it is re-create it, else you can reuse the
          * the original, but i suspect that calling release() in onPause() allows the
          * song to get cleaned up by Java's Garbage Collector.
          */
         oursong = MediaPlayer.create(MainActivity.this, R.raw.a);
         oursong.seekTo(pos); // You will probably want to save an int to restore here
         oursong.start();
    }
   /*
    * May want to add two methods here: onSaveInstanceState(Bundle outstate) &
    * onRestoreInstanceState(Bundle savedInstanceState) to maintain playback position
    * in onResume instead of just restarting the song.
    */

   private final OnPageChangeListener MyViewPagerListener = new OnPageChangeListener() {

            @Override
            public void onPageSelected(int pos) {
              if (pos == adapter.getCount() - 1){
                 // adding null checks for safety
                 if(oursong != null){
                    oursong.pause();
                 }

               } else if (!oursong.isPlaying()){ 

                // adding null check for safety
                if(oursong != null){
                    oursong.start();
                }
              }         
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
             // TODO Auto-generated method stub

            }

            @Override
            public void onPageScrollStateChanged(int arg0) {
            // TODO Auto-generated method stub

            }
        };

 }

Answer 1

每次旋转手机并从纵向切换到横向时，活动都会被销毁并重新创建，这意味着再次调用onCreate（）。

将此行添加到清单中，告诉android在这种情况下不要破坏您的活动。

android:configChanges="orientation|screenSize"

更多信息HERE

用户在横向模式下滑动时，Mediaplayer将再次开始播放音乐

1 个答案: