java - Android MediaPlayer onPause()

Question

我是一名 Android 初学者开发人员，我想开发一个基本的应用程序，该应用程序在打开时开始播放音乐，在完成时停止(onPause)。当我创建方法“onPause”时，我的条件“musica.stop();”不工作。

我的代码:

import android.media.MediaPlayer;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageButton;
import android.widget.Toast;

public class MainActivity extends ActionBarActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final MediaPlayer mpBtnsom = MediaPlayer.create(this, R.raw.somvoa);
        ImageButton btn1 = (ImageButton) findViewById(R.id.imageButton2);

        MediaPlayer musica = MediaPlayer.create(this, R.raw.sommusica);
        musica.start();
        musica.setLooping(true);

        btn1.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                mpBtnsom.start();
            }
        });
    }

    public void toast2(View view){
        Toast toast = Toast.makeText(MainActivity.this, "Botão ToastMessage", Toast.LENGTH_LONG);
        toast.show();
    }

    public void toast(View view){
        Toast toast = Toast.makeText(MainActivity.this, "Botão Felpudo", Toast.LENGTH_SHORT);
        toast.show();
    }

    protected void onPause(){
        super.onPause();

        musica.stop();
        finish();
    }
}

Answer 1

问题是在您的 onPause() 方法中无法访问变量 musica。您应该声明变量 musica 以便在类中全局使用，如下所示。

public class MainActivity extends ActionBarActivity {

    private MediaPlayer musica;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final MediaPlayer mpBtnsom = MediaPlayer.create(this, R.raw.somvoa);
        ImageButton btn1 = (ImageButton) findViewById(R.id.imageButton2);

        musica = MediaPlayer.create(this, R.raw.sommusica);
        musica.start();
        musica.setLooping(true);

        btn1.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                mpBtnsom.start();
            }
        });
    }

    public void toast2(View view){
        Toast toast = Toast.makeText(MainActivity.this, "Botão ToastMessage", Toast.LENGTH_LONG);
        toast.show();
    }

    public void toast(View view){
        Toast toast = Toast.makeText(MainActivity.this, "Botão Felpudo", Toast.LENGTH_SHORT);
        toast.show();
    }

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

        musica.stop();
        finish();
    }
}