我的应用程序在请求权限前崩溃

Question

第一次运行应用程序时崩溃（logcat上没有任何内容）。那么你可以看到权限的请求，并在您授予权限后，您可以打开该应用程序，它工作正常。

public class MainActivity extends AppCompatActivity { 

    String [] PERMISSIONS = {Manifest.permission.RECORD_AUDIO, Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE}; 
    int PERMISSION_ALL = 1; 

    Button record; 
    Button play; 
    Button stop; 

    MediaPlayer mediaPlayer; 
    MediaRecorder mediaRecorder; 

    String outPutFile; 

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

     //--------------------- 
     //asking for permission 
     //--------------------- 

     if(!hasPermissions(this, PERMISSIONS)){ 
      ActivityCompat.requestPermissions(this, PERMISSIONS, PERMISSION_ALL); 
     } 
     record = (Button) findViewById(R.id.recordbutton); 
     play = (Button) findViewById(R.id.playbutton); 
     stop = (Button) findViewById(R.id.stopbutton); 

     if (outPutFile==null){ 
      play.setEnabled(false); 
     } 

     stop.setEnabled(false); 

     outPutFile = Environment.getExternalStorageDirectory().getAbsolutePath() + "/recording.3gp"; 

     mediaRecorder = new MediaRecorder(); 
     mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); 
     mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP); 
     mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); 
     mediaRecorder.setOutputFile(outPutFile); 

     //--------------------- 
     //recording 
     //--------------------- 

     record.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       try { 
        mediaRecorder.prepare(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
        //Toast.makeText(getApplicationContext(),"error", Toast.LENGTH_LONG).show(); 

       } 
       mediaRecorder.start(); 
       record.setEnabled(false); 
       stop.setEnabled(true); 

       Toast.makeText(getApplicationContext(),"recording", Toast.LENGTH_LONG).show(); 
      } 
     }); 

     stop.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       mediaRecorder.stop(); 
       mediaRecorder.release(); 
       mediaRecorder = null; 
       stop.setEnabled(false); 
       play.setEnabled(true); 

       Toast.makeText(getApplicationContext(), "Audio recorded", Toast.LENGTH_LONG).show(); 
      } 
     }); 
     //--------------------- 
     //playing the record 
     //--------------------- 

     play.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       mediaPlayer = new MediaPlayer(); 

       try { 
        mediaPlayer.setDataSource(outPutFile); 
        mediaPlayer.prepare(); 

        Toast.makeText(getApplicationContext(), "Audio Playing", Toast.LENGTH_LONG).show(); 


       } catch (Exception e) { 

       } 
       mediaPlayer.start(); 

       record.setEnabled(true); 
      } 
     }); 


    } 

    public static boolean hasPermissions(Context context, String... permissions) { 
     if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && context != null && permissions != null) { 
      for (String permission : permissions) { 
       if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED) { 
        return false; 
       } 
      } 
     } 
     return true; 
    } 
} 

这是为什么？

logcat-

07-30 19:03:03.812 4491-4491/com.example.tsuryohananov.voicerecorder E/AndroidRuntime: FATAL EXCEPTION: main 
                         Process: com.example.tsuryohananov.voicerecorder, PID: 4491 
                         java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.tsuryohananov.voicerecorder/com.example.tsuryohananov.voicerecorder.MainActivity}: java.lang.RuntimeException: setAudioSource failed. 
                          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2817) 
                          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892) 
                          at android.app.ActivityThread.-wrap11(Unknown Source:0) 
                          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593) 
                          at android.os.Handler.dispatchMessage(Handler.java:105) 
                          at android.os.Looper.loop(Looper.java:164) 
                          at android.app.ActivityThread.main(ActivityThread.java:6540) 
                          at java.lang.reflect.Method.invoke(Native Method) 
                          at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240) 
                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767) 
                         Caused by: java.lang.RuntimeException: setAudioSource failed. 
                          at android.media.MediaRecorder.setAudioSource(Native Method) 
                          at com.example.tsuryohananov.voicerecorder.MainActivity.onCreate(MainActivity.java:64) 
                          at android.app.Activity.performCreate(Activity.java:6980) 
                          at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213) 
                          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770) 
                          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)  
                          at android.app.ActivityThread.-wrap11(Unknown Source:0)  
                          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)  
                          at android.os.Handler.dispatchMessage(Handler.java:105)  
                          at android.os.Looper.loop(Looper.java:164)  
                          at android.app.ActivityThread.main(ActivityThread.java:6540)  
                          at java.lang.reflect.Method.invoke(Native Method)  
                          at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)  
                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)  

Answer 1

我动议代码：

mediaRecorder = new MediaRecorder(); 
    mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); 
    mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP); 
    mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); 
    mediaRecorder.setOutputFile(outPutFile); 

到

record.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      mediaRecorder = new MediaRecorder(); 
      mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); 
      mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP); 
      mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); 
      mediaRecorder.setOutputFile(outPutFile); 
      try { 
       mediaRecorder.prepare(); 

      } catch (IOException e) { 
       e.printStackTrace(); 

      } 
      record.setEnabled(false); 
      stop.setEnabled(true); 
      mediaRecorder.start(); 

      Toast.makeText(getApplicationContext(),"recording", Toast.LENGTH_LONG).show(); 
     } 
    }); 

的问题是，在第一运行mediaRecorder.setAudioSource（MediaRecorder.AudioSource.MIC） ;

在用户授予权限之前运行。

我认为还有其他的方式，也许像：

if (hasPermissions(this, PERMISSIONS)) { 
mediaRecorder = new MediaRecorder(); 
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); 
mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP); 
mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); 
mediaRecorder.setOutputFile(outPutFile); 

    }