치명적인 예외 : 주요 java.lang.RuntimeException가 : java.lang.NullPointerException이 내가 할</p> <p>: 활동을

Question

02-18 21:26:32.055: E/AndroidRuntime(1529): FATAL EXCEPTION: main 
02-18 21:26:32.055: E/AndroidRuntime(1529): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.yellomecha.pianobirds/com.yellomecha.pianobirds.Main}: java.lang.NullPointerException 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at android.app.ActivityThread.access$600(ActivityThread.java:141) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at android.os.Handler.dispatchMessage(Handler.java:99) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at android.os.Looper.loop(Looper.java:137) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at android.app.ActivityThread.main(ActivityThread.java:5103) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at java.lang.reflect.Method.invokeNative(Native Method) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at java.lang.reflect.Method.invoke(Method.java:525) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at dalvik.system.NativeStart.main(Native Method) 
02-18 21:26:32.055: E/AndroidRuntime(1529): Caused by: java.lang.NullPointerException 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at com.yellomecha.pianobirds.Wire.<init>(Wire.java:20) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at com.yellomecha.pianobirds.Game.<init>(Game.java:24) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at com.yellomecha.pianobirds.Main.onCreate(Main.java:26) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at android.app.Activity.performCreate(Activity.java:5133) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175) 
02-18 21:26:32.055: E/AndroidRuntime(1529):  ... 11 more 

시작 활동 ComponentInfo {com.yellomecha.pianobirds/com.yellomecha.pianobirds.Main}을 (를) 시작할 수 없습니다 Eclipse에서 다음을 실행할 때이 오류가 발생했습니다. 왜이 오류가 발생합니까? 전혀 모르겠습니다. 나는이 사이트에서 둘러 보았고, 많은 사람들이 여러 가지 이유 때문에이 오류가 발생하는 것으로 보인다.

public class Main extends Activity 
{ 

private static Game game; 
public static Handler updateHandler = new Handler() 
{ 
    public void handleMessage(Message msg) 
    { 
     game.update(); 
     game.invalidate(); 
     super.handleMessage(msg); 
    } 
}; 

/** On Create **/ 
public void onCreate(Bundle savedInstanceState) 
{ 
    super.onCreate(savedInstanceState); 
    game = new Game(this); 
    //LinearLayout layout = (LinearLayout) findViewById(R.layout.activity_main);; 
    //layout.setOrientation(LinearLayout.HORIZONTAL); 

    setContentView(game); 
    Thread mainThread = new Thread(new UpdateThread()); 
    mainThread.start(); 
} 

public class UpdateThread implements Runnable 
{ 
    @Override 
    public void run() 
    { 
     while(true) 
      Main.updateHandler.sendEmptyMessage(0); 
    } 

} 

} 

게임 클래스

public class Game extends View 
{ 
private Bitmap birdImage; 
private Paint paint; 
private Wire top,bottom; 

public Game(Context context) 
{ 
    super(context); 
    birdImage = Bitmap.createBitmap(BitmapFactory.decodeResource(this.getResources(), R.drawable.toucan)); 
    paint = new Paint(); 
    paint.setStrokeWidth(5); 
    paint.setColor(Color.BLACK); 
    top = new Wire(getWidth(),(float)getHeight()/3, true); 
    bottom = new Wire(getWidth(), (float)getHeight()*2/3, false); 

} 

//called every frame 
protected void onDraw(Canvas canvas) 
{ 
    canvas.drawBitmap(birdImage, getWidth(), getHeight(), paint); 
    top.draw(canvas, paint); 
    bottom.draw(canvas, paint); 
} 

public void update() 
{ 

} 

} 

및 라인으로 매니페스트 파일

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.yellomecha.pianobirds" 
android:versionCode="1" 
android:versionName="1.0" > 

<uses-sdk 
    android:minSdkVersion="8" 
    android:targetSdkVersion="19" /> 

<application 
    android:allowBackup="true" 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" 
    android:theme="@style/AppTheme" > 
    <activity 
     android:name="com.yellomecha.pianobirds.Main" 
     android:label="@string/app_name" > 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
</application> 

Answer 1

장소 라인

log.i(TAG,"OK1"); 
... code line 
log.i(TAG,"OK2"); 
... code line 
log.i(TAG,"OK3"); 
. 
. 
. 

을 사용하면 NULL 오류가있는 코드 줄을 찾을 수 있습니다.

Answer 2

귀하의 NullPointerException은 Wire.java의 20 번째 라인에 있습니다. 액세스하기 전에 해당 행의 모든 ​​객체가 초기화되었는지 확인하십시오.