java - 如何播放主屏幕和副屏幕上添加的音乐？

Question

我是 Android 世界的新手。我正在开发一个应用程序，主屏幕上有 6 个按钮，第二屏幕上有 5 个按钮。主屏幕上的 5 个按钮应该能够在用户单击这些按钮时播放音乐。每个按钮应该能够播放与原始文件夹中的音乐相对应的不同音乐。主屏幕上的第六个按钮应允许用户转到下一个屏幕(第二个屏幕)。同样，第二个屏幕上的 5 个按钮应该播放与原始文件夹中的音乐相对应的音乐。请看看我的代码..我不知道我的代码有什么问题？

我的主要 Java 代码如下所示...

public class MainActivity extends Activity implements OnClickListener{  

    public class onClickListener implements OnClickListener {       

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent i = new Intent("com.example.playaudio.SecondActivity");
            startActivity(i);   

        }               
    }

    public class onClick {

    }

    private MediaPlayer mp;
    Button button;  

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = (Button) findViewById(R.id.buttonSwitch);
        button.setOnClickListener(new onClickListener());
        setVolumeControlStream(AudioManager.STREAM_MUSIC);
        Button button1=(Button)findViewById(R.id.button_1);
        Button button2=(Button)findViewById(R.id.button_2);
        Button button3=(Button)findViewById(R.id.button_3);
        Button button4=(Button)findViewById(R.id.button_4);
        Button button5=(Button)findViewById(R.id.button_5);
        button1.setOnClickListener(this);
        button2.setOnClickListener(this);
        button3.setOnClickListener(this);
        button4.setOnClickListener(this);
        button5.setOnClickListener(this);       
    }

    private void setOnClickListener(
            com.example.playaudio.MainActivity.onClick onClick) {
        // TODO Auto-generated method stub      

    }

    public static void onClick(View v) {
        int resId;
        switch (v.getId()) {
        case R.id.button_1:
            resId = R.raw.a;
            break;
        case R.id.button_2:
            resId = R.raw.b;
            break;
        case R.id.button_3: 
            resId = R.raw.c;
            break;
        case R.id.button_4:
            resId = R.raw.d;
            break;
        case R.id.button_5:
            resId = R.raw.e;
            break;      
        default:
            resId = R.raw.a;
            break;
        }

        // Release any resources from previous MediaPlayer
        if (mp != null) {
            mp.release();

        }
        // Create a new MediaPlayer to play this sound
        mp = MediaPlayer.create(this, resId);
        mp.start();
    }

    {
             startActivity(new Intent(MainActivity.this,SecondActivity.class));
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;

    }


    @Override

    protected void onDestroy() {
        if(null!=mp){
            mp.release();
        }
        super.onDestroy();
    }
}

第二个屏幕 Java 类

import com.example.playaudio.MainActivity.onClick;

import android.app.Activity;

import android.content.Intent;

import android.media.AudioManager;

import android.media.MediaPlayer;

import android.os.Bundle;

import android.view.Menu;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class SecondActivity extends Activity

{

@Override

protected void onCreate(Bundle savedInstanceState)

{

// TODO Auto-generated method stub
super.onCreate(savedInstanceState);




setContentView(R.layout.activity_second);




b= (Button) findViewById (R.id.buttonSwitch);




b.setOnClickListener(new onClick());




setVolumeControlStream(AudioManager.STREAM_MUSIC);




Button button7=(Button)findViewById(R.id.button7);




Button button8=(Button)findViewById(R.id.button8);




Button button9=(Button)findViewById(R.id.button9);




Button button10=(Button)findViewById(R.id.button10);




Button button11=(Button)findViewById(R.id.button11);




button7.setOnClickListener((OnClickListener) this);




button8.setOnClickListener((OnClickListener) this);




button9.setOnClickListener((OnClickListener) this);




button10.setOnClickListener((OnClickListener) this);




button11.setOnClickListener((OnClickListener) this);

}

public void onClick(View v) {

int resId;

switch (v.getId()) {




case R.id.button7:




    resId = R.raw.f;




    break;




case R.id.button8:




    resId = R.raw.g;




    break;




case R.id.button9:




    resId = R.raw.h;




    break;




case R.id.button10:




    resId = R.raw.i;




    break;




case R.id.button11:




    resId = R.raw.j;




    break;




default:




    resId = R.raw.a;




    break;




}




 {




     startActivity(new Intent(MainActivity.this,SecondActivity.class));




 }

Answer 1

我认为您没有准备好媒体播放器。我给你留下了一个有效的代码。我总是准备同一首歌。请记住根据您的音乐进行更改，并创建一个“assets”文件夹，您可以在其中放置“.mp3”文件。

public class MediaPlayerActivity extends ActionBarActivity implements View.OnClickListener {

private Button mButton1;
private Button mButton2;
private Button mButton3;
private Button mButton4;
private Button mButton5;
private Button mButton6;
private MediaPlayer mPlayer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my);

    mButton1 = (Button) findViewById(R.id.button1);
    mButton2 = (Button) findViewById(R.id.button2);
    mButton3 = (Button) findViewById(R.id.button3);
    mButton4 = (Button) findViewById(R.id.button4);
    mButton5 = (Button) findViewById(R.id.button5);
    mButton6 = (Button) findViewById(R.id.button6);

    mButton1.setOnClickListener(this);
    mButton2.setOnClickListener(this);
    mButton3.setOnClickListener(this);
    mButton4.setOnClickListener(this);
    mButton5.setOnClickListener(this);
    mButton6.setOnClickListener(this);

}

@Override
public void onClick(View view) {
    switch (view.getId()) {
        case R.id.button1:
            playMusic("lori.mp3");
            break;
        case R.id.button2:
            playMusic("lori.mp3");
            break;
        case R.id.button3:
            playMusic("lori.mp3");
            break;
        case R.id.button4:
            playMusic("lori.mp3");
            break;
        case R.id.button5:
            playMusic("lori.mp3");
            break;
        case R.id.button6:
            Intent intent = new Intent(this, SecondActivity.class);
            startActivity(intent);
            break;
    }
}

private void playMusic(String songName) {
    if (mPlayer != null && mPlayer.isPlaying()) {
        mPlayer.stop();
        mPlayer.release();
        mPlayer = null;
    }

    try {
        mPlayer = new MediaPlayer();
        mPlayer.reset();
        AssetFileDescriptor descriptor = getAssets().openFd(songName);
        mPlayer.setDataSource(descriptor.getFileDescriptor(), descriptor.getStartOffset(), descriptor.getLength());
        mPlayer.prepare();
        mPlayer.start();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

}

我希望它对你有用。如果此代码适合您，请记住将答案标记为正确。谢谢!