MediaFile 앱에서 예외 처리하기

Question

원시 폴더에 저장된 사운드를 재생하기위한 미디어 파일 앱을 개발 중입니다. 전체적으로 약 32 개의 소리가 있습니다.

12-19 12:33:05.420: WARN/dalvikvm(699): threadid=3: thread exiting 
with uncaught exception (group=0x4000fe70) 
12-19 12:33:05.441: ERROR/AndroidRuntime(699): Uncaught handler: 
thread main exiting due to uncaught exception 
12-19 12:33:05.460: ERROR/AndroidRuntime(699): 
java.lang.NullPointerException 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
com.myapps.media.MainScreen$8.onClick(MainScreen.java:244) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.view.View.performClick(View.java:2179) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.view.View.onTouchEvent(View.java:3828) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.widget.TextView.onTouchEvent(TextView.java:6291) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.view.View.dispatchTouchEvent(View.java:3368) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
com.android.internal.policy.impl.PhoneWindow 
$DecorView.superDispatchTouchEvent(PhoneWindow.java:1707) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent 
(PhoneWindow.java:1197) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.app.Activity.dispatchTouchEvent(Activity.java:1993) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
com.android.internal.policy.impl.PhoneWindow 
$DecorView.dispatchTouchEvent(PhoneWindow.java:1691) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.view.ViewRoot.handleMessage(ViewRoot.java:1525) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.os.Handler.dispatchMessage(Handler.java:99) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.os.Looper.loop(Looper.java:123) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
android.app.ActivityThread.main(ActivityThread.java:3948) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
java.lang.reflect.Method.invokeNative(Native Method) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
java.lang.reflect.Method.invoke(Method.java:521) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run 
(ZygoteInit.java:782) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:540) 
12-19 12:33:05.460: ERROR/AndroidRuntime(699):  at 
dalvik.system.NativeStart.main(Native Method) 
12-19 12:33:05.520: INFO/Process(563): Sending signal. PID: 699 SIG: 3 
12-19 12:33:05.520: INFO/dalvikvm(699): threadid=7: reacting to signal 
3 
12-19 12:33:05.601: INFO/dalvikvm(699): Wrote stack trace to '/data/ 
anr/traces.txt' 
12-19 12:33:05.982: INFO/ARMAssembler(563): generated 
scanline__00000077:03515104_00000000_00000000 [ 27 ipp] (41 ins) at 
[0x27c718:0x27c7bc] in 982527 ns 
12-19 12:33:06.011: INFO/ARMAssembler(563): generated 
scanline__00000077:03515104_00001001_00000000 [ 64 ipp] (84 ins) at 
[0x27c7c0:0x27c910] in 1804978 ns 

:

Button btnGrowUp = (Button) this.findViewById(R.id.GrowUp); 
btnGrowUp.setOnClickListener(btnGrowUpListener); 

private OnClickListener btnGrowUpListener = new OnClickListener() 
{ 
    public void onClick(View v) 
    { 
     //Toast.makeText(getBaseContext(), "Grow Up audio file is being played", Toast.LENGTH_SHORT).show(); 

     MediaPlayer mp = MediaPlayer.create(MainScreen.this, R.raw.growup); 
     mp.start(); 
    } 
}; 

내가 내 로그 캣 창에서 후속 메시지와 함께 "응용 프로그램이 예기치 않게 중지"라는 런타임 예외를 얻을 : 그리고 이것은 내가 각 버튼의 클릭에 일을 이야 무엇인가

이 문제를 해결하는 방법? 당신

Maqsood

Answer 1

감사합니다 MediaPlayer constructor 사용중인위한 Javadoc는 플레이어의 생성이 실패 할 경우가 null를 반환합니다 말한다.

start 메서드를 호출하기 전에 생성이 성공했는지 확인하지 않으므로 위의 스택 추적을 기반으로하면 예외가 발생할 가능성이 가장 높습니다.