当我在功能中使用它时，音频文件无法播放

Question

我正在创建一个需要按下按钮时播放音频的Android应用程序。但是它不会播放音乐，尽管其余的代码都起作用。另外，上下文中有一个错误，表示上下文无法解析为变量。

这是我的主要活动

public class BroadcastNewSms extends Activity { 



    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.androidexample_broadcast_newsms); 
     Button b1; 
     b1 = (Button) findViewById(R.id.button1); 

     b1.setOnClickListener(new OnClickListener() 

     { 



     public void onClick(View v) 

     { 



      MediaPlayer mp; 
      mp = MediaPlayer.create(context,R.raw.hospital_alarm); 

      mp.start(); 

      String phoneNumber = "+9198zxxxxxxx"; 

      String message = "Ambulance sent!"; 



      SmsManager smsManager = SmsManager.getDefault(); 

      smsManager.sendTextMessage(phoneNumber, null, message, null, null); 



     } 
     }); 




    } 
} 

Answer 1

而不是context尝试getApplicationContext()方法

public class BroadcastNewSms extends Activity 
{ 
    @Override 
    protected void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.androidexample_broadcast_newsms); 
     Button b1; 
     b1 = (Button) findViewById(R.id.button1); 
     b1.setOnClickListener(new OnClickListener() 
     { 
      public void onClick(View v) 
      { 
       MediaPlayer mp; 
       mp = MediaPlayer.create(getApplicationContext(),R.raw.hospital_alarm); 
       mp.start(); 
       String phoneNumber = "+9198989898";  
       String message = "Ambulance sent!"; 
       SmsManager smsManager = SmsManager.getDefault(); 
       smsManager.sendTextMessage(phoneNumber, null, message, null, null); 
      } 
     }); 
    } 
} 

Answer 2

点击此处查看How to play the audio files directly from res/raw folder?

int resID=context.getResources().getIdentifier(Name_of_file, "raw", getPackageName()); 
MediaPlayer mediaPlayer=MediaPlayer.create(this,resID); 
mediaPlayer.start();