So spielen Sie eine MP3-Datei mit MediaPlayer, wenn Sie einen Button berühren

Question

Ich bekomme den Fehler unten jedes Mal, wenn ich versuche, den Song zu spielen, ich den Song erfolgreich spielen, wenn Sie den Code in der Hauptaktivität hinzufügen, obwohl versuchen, in anderen der zu spielen Die App stürzt ab und ich möchte nur wissen, warum das passiert und wie ich das Problem lösen könnte.

Fehler:

E/MediaPlayer: error (1, -2147483648) 
D/MediaPlayer: create failed: 
       java.io.IOException: Prepare failed.: status=0x1 
        at android.media.MediaPlayer._prepare(Native Method) 
        at android.media.MediaPlayer.prepare(MediaPlayer.java:1158) 
        at android.media.MediaPlayer.create(MediaPlayer.java:944) 
        at android.media.MediaPlayer.create(MediaPlayer.java:915) 
        at com.example.android.phaseup.AviationSongActivity.onCreate(AviationSongActivity.java:19) 
        at android.app.Activity.performCreate(Activity.java:6251) 
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) 
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) 
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
        at android.app.ActivityThread.-wrap11(ActivityThread.java) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:148) 
        at android.app.ActivityThread.main(ActivityThread.java:5422) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
D/AndroidRuntime: Shutting down VM 
E/AndroidRuntime: FATAL EXCEPTION: main 
        Process: com.example.android.phaseup, PID: 1644 
        java.lang.NullPointerException: Attempt to invoke virtual method 'void android.media.MediaPlayer.start()' on a null object reference 
         at com.example.android.phaseup.AviationSongActivity$1.onClick(AviationSongActivity.java:36) 
         at android.view.View.performClick(View.java:5204) 
         at android.view.View$PerformClick.run(View.java:21155) 
         at android.os.Handler.handleCallback(Handler.java:739) 
         at android.os.Handler.dispatchMessage(Handler.java:95) 
         at android.os.Looper.loop(Looper.java:148) 
         at android.app.ActivityThread.main(ActivityThread.java:5422) 
         at java.lang.reflect.Method.invoke(Native Method) 
         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
Application terminated. 

-Code MainActivity.java:

package com.example.android.phaseup; 

import android.content.Intent; 
import android.net.Uri; 
import android.os.Bundle; 
import android.support.v7.app.AppCompatActivity; 
import android.view.View; 
import android.widget.TextView; 

public class MainActivity extends AppCompatActivity { 

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

     //Call BlueBook Activity 
     TextView blueBook = (TextView) findViewById(R.id.blue_book); 

     //Set a click listener in that View 
     blueBook.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent blueBookIntent = new Intent(MainActivity.this, BlueBookActivity.class); 
       startActivity(blueBookIntent); 
      } 
     }); 

     //Call Aviation Song Activity 
     TextView aviationSong = (TextView) findViewById(R.id.aviation_songs); 

     //Set a click listener in that View 
     aviationSong.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent aviationIntent = new Intent(MainActivity.this, AviationSongActivity.class); 
       startActivity(aviationIntent); 
      } 
     }); 

     //Call Soldier's Creed Activity 
     TextView soldierCreed = (TextView) findViewById(R.id.soldier_creed); 

     //Set a click listener in that View 
     soldierCreed.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent soldierCreedIntent = new Intent(MainActivity.this, SoldierCreedActivity.class); 
       startActivity(soldierCreedIntent); 
      } 
     }); 

     //Call Room Inspection Activity 
     TextView roomInspection = (TextView) findViewById(R.id.room_inspection); 

     //Set a click listener in that View 
     roomInspection.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent roomInspectionIntent = new Intent(MainActivity.this, RoomInspectionActivity.class); 
       startActivity(roomInspectionIntent); 
      } 
     }); 

     //Call Wall Locker Inspection Activity 
     TextView wallLocker = (TextView) findViewById(R.id.wall_Locker_inspection); 

     //Set a click listener in that View 
     wallLocker.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent wallLockerIntent = new Intent(MainActivity.this, WallLockerActivity.class); 
       startActivity(wallLockerIntent); 
      } 
     }); 

     //Call ASU Inspection Activity 
     TextView asuInspection = (TextView) findViewById(R.id.asu_inspection); 

     //Set a click listener in that View 
     asuInspection.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent asuIntent = new Intent(MainActivity.this, ASUActivity.class); 
       startActivity(asuIntent); 
      } 
     }); 

     //Feedback button. 
     TextView sendFeedBack = (TextView) findViewById(R.id.send_feedback); 
     sendFeedBack.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent sendFeedbackIntent = new Intent(Intent.ACTION_SENDTO); 
       sendFeedbackIntent.setData(Uri.parse("mailto: algenisromero@gmail.com")); 
       sendFeedbackIntent.putExtra(Intent.EXTRA_SUBJECT, "Phase UP Support."); 
       if (sendFeedbackIntent.resolveActivity(getPackageManager()) != null) { 
        startActivity(sendFeedbackIntent); 
       } 
      } 
     }); 

    } 
} 

-Code AviationSongActivity.java:

package com.example.android.phaseup; 

import android.media.MediaPlayer; 
import android.os.Bundle; 
import android.support.v7.app.AppCompatActivity; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 

public class AviationSongActivity extends AppCompatActivity { 

    //Media Player variable. 
    MediaPlayer mMediaPlayer; 

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

     //Create and Upload the MP3 file. 
     mMediaPlayer = MediaPlayer.create(this, R.raw.aviationsong); 


     //The aviation song text show in the screen. 
     TextView textViewAviation = (TextView) findViewById(R.id.textview_aviation); 
     textViewAviation.setText("High above the best, high above the best \n\n" + 
       "We are Army Aviation USA, \n\n" + 
       "proud and strong We meet the test \n\n" + 
       "Skies filled with thunder \n\n" + 
       "Wearing silver wings upon our chest \n\n" + 
       "We meet the needs of Ground Command \n\n" + 
       "As we aid the Nation's quest \n\n" + 
       "Army Aviation, flying high above the best!"); 

     //Listener to play sound when user touched. 
     Button playButton = (Button) findViewById(R.id.play_sound); 

     playButton.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
      mMediaPlayer.start(); 

      } 
     }); 
    } 
} 

-Code activity_aviation_song.xml

<?xml version="1.0" encoding="utf-8"?> 
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent"> 

    <LinearLayout 
     android:id="@+id/activity_aviation_song" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:orientation="vertical" 
     tools:context="com.example.android.phaseup.AviationSongActivity"> 

     <RelativeLayout 
      android:layout_width="match_parent" 
      android:layout_height="170dp" 
      android:background="@color/colorPrimaryDark"> 

      <Button 
       android:id="@+id/play_sound" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_centerInParent="true" 
       android:text="PLAY" 
       android:textSize="56sp" 
       android:textStyle="bold" 
       android:textColor="@android:color/white" 
       android:background="@null"/> 

     </RelativeLayout> 

     <TextView 
      android:id="@+id/textview_aviation" 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:layout_margin="32dp" 
      android:gravity="center" 
      android:textSize="18sp" /> 

    </LinearLayout> 
</ScrollView> 

Sie können den vollständigen Code der App in meinem GitHub Konto PhaseUp App

Danke für Ihre Hilfe finden!

Answer 1

Update your MP3 file so ist es nicht leer oder beschädigt.

Der Code sieht ansonsten gut aus.