Приложение аварийно завершает работу при нажатии кнопки, которая запускает другое действие.

Question

Как и название, мое приложение падает, когда я нажимаю кнопку, чтобы изменить действие. Он не показывает ошибок в eclipse и открывается сначала, но закрывается, когда я нажимаю кнопку. Первоначально приложение не было открыто вообще, но я установил переменные внутри onClick(), которые позволили ему открыть.

манифеста

<application 
    android:allowBackup="true" 
    android:icon="@drawable/globe" 
    android:label="@string/app_name" 
    android:theme="@style/AppTheme" > 
    <activity 
     android:name="com.example.geoquizlab1solution.QuizActivity" 
     android:label="@string/app_name" > 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
    <activity android:screenOrientation="unspecified" android:name="com.example.geoquizlab1solution.SportsQuiz"/> 
    </application> 

Класс первой активности ActivityQuiz.java:

package com.example.geoquizlab1solution; 

import android.app.Activity; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.os.Bundle; 
import android.preference.PreferenceManager; 
import android.view.Menu; 
import android.view.View; 
import android.widget.Button; 
import android.widget.ImageButton; 
import android.widget.TextView; 
import android.widget.Toast; 

public class QuizActivity extends Activity { 

private Button mTrueButton; 
private Button mFalseButton; 
private ImageButton mNextButton; 
private ImageButton mPreviousButton; 
private TextView mQuestionTextView; 
private Button mResetButton; 
private Button mSportsButton; 
private Button mGeoButton; 
//private Button mMusicButton; 
private int counter = 0; 


private TrueFalse[] mQuestionBank = new TrueFalse[] { 
     new TrueFalse(R.string.question_oceans, true), 
     new TrueFalse(R.string.question_mideast, false), 
     new TrueFalse(R.string.question_africa, false), 
     new TrueFalse(R.string.question_americas, true), 
     new TrueFalse(R.string.question_asia, true) 
}; 


private int mCurrentIndex=0; 

private void updateQuestion(){ 
    int question = mQuestionBank[mCurrentIndex].getQuestion(); 
    mQuestionTextView.setText(question); 
} 

private void checkAnswer(boolean userPressedTrue) { 
    boolean answerIsTrue = mQuestionBank[mCurrentIndex].isTrueQuestion(); 
    int messageResId = 0; 

    SharedPreferences app_preferences = 
      PreferenceManager.getDefaultSharedPreferences(this); 

    if (userPressedTrue == answerIsTrue) { 
     messageResId = R.string.correct_toast; 
     counter++; 

    } 
     else { 
      messageResId = R.string.incorrect_toast; 
     } 
    SharedPreferences.Editor editor = app_preferences.edit(); 
     editor.putInt("count", counter); 
    Toast.makeText(this, messageResId, Toast.LENGTH_SHORT).show(); 
    Toast.makeText(this,"Score:" + counter, Toast.LENGTH_SHORT).show(); 
    editor.commit(); 
     } 

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


    mGeoButton = (Button)findViewById(R.id.geo_button); 
    mGeoButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      counter = 0; 
      Toast.makeText(getApplicationContext(), "Score: 0", 
        Toast.LENGTH_SHORT).show(); 
      mCurrentIndex = 0; 
      updateQuestion(); 
     } 
    }); 

    mSportsButton = (Button)findViewById(R.id.sports_button); 
    mSportsButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      final Intent intent1 = new Intent(QuizActivity.this, SportsQuiz.class); 
      if (intent1 != null) { 
       startActivity(intent1); 
      } 
     } 
    }); 

    /* mMusicButton = (Button)findViewById(R.id.music_button); 
    mMusicButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      Intent intent = new Intent(this, MusicQuiz.java); 
     } 
    });*/ 

    mTrueButton = (Button)findViewById(R.id.true_button); 
    mTrueButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      checkAnswer(true); 

     } 
    }); 

    mFalseButton = (Button)findViewById(R.id.false_button); 
    mFalseButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      checkAnswer(false); 
      } 
    }); 
    mQuestionTextView = (TextView)findViewById(R.id.question_text_view); 
    ((View) mQuestionTextView) .setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length; 
      updateQuestion(); 
     } 
    }); 
    updateQuestion(); 

    mPreviousButton = (ImageButton)findViewById(R.id.previous_button); 
    ((View) mPreviousButton) .setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
       if (mCurrentIndex != 0) { 
        mCurrentIndex = (mCurrentIndex - 1) % mQuestionBank.length; 
       updateQuestion(); 
       } 
       else { 
        mCurrentIndex = (mCurrentIndex + 4) % mQuestionBank.length; 
       } 
     } 
    }); 
    updateQuestion(); 


    mNextButton = (ImageButton)findViewById(R.id.next_button); 
    ((View) mNextButton).setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 

      mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length; 
      updateQuestion(); 
     } 
     }); 
    updateQuestion(); 

    mResetButton = (Button)findViewById(R.id.reset_button); 
    ((View) mResetButton).setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      counter = 0; 
      Toast.makeText(getApplicationContext(), "Score: 0", 
        Toast.LENGTH_SHORT).show(); 
      mCurrentIndex = 0; 
      updateQuestion(); 
     } 
    }); 
} 




@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.activity_quiz, menu); 
    return true; 
} 

}

SportsQuiz.java:

package com.example.geoquizlab1solution; 

import android.app.Activity; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.os.Bundle; 
import android.preference.PreferenceManager; 
import android.view.Menu; 
import android.view.View; 
import android.widget.Button; 
import android.widget.ImageButton; 
import android.widget.TextView; 
import android.widget.Toast; 


public class SportsQuiz extends Activity { 
private Button mTrueButton; 
private Button mFalseButton; 
private ImageButton mNextButton; 
private ImageButton mPreviousButton; 
private TextView mQuestionTextView; 
private Button mResetButton; 
private Button mSportsButton; 
private Button mGeoButton; 
//private Button mMusicButton; 
private int counter = 0; 
Intent intent1 = getIntent(); 
Intent intent = new Intent(this, SportsQuiz.class); 


private TrueFalse[] mQuestionBank = new TrueFalse[] { 
     new TrueFalse(R.string.question_baseball, true), 
     new TrueFalse(R.string.question_football, false), 
     new TrueFalse(R.string.question_basketball, false), 
     new TrueFalse(R.string.question_hockey, true), 
     new TrueFalse(R.string.question_soccer, true) 
}; 


private int mCurrentIndex=0; 

private void updateQuestion(){ 
    int question = mQuestionBank[mCurrentIndex].getQuestion(); 
    mQuestionTextView.setText(question); 
} 

private void checkAnswer(boolean userPressedTrue) { 
    boolean answerIsTrue = mQuestionBank[mCurrentIndex].isTrueQuestion(); 
    int messageResId = 0; 

    SharedPreferences app_preferences = 
      PreferenceManager.getDefaultSharedPreferences(this); 

    if (userPressedTrue == answerIsTrue) { 
     messageResId = R.string.correct_toast; 
     counter++; 

    } 
     else { 
      messageResId = R.string.incorrect_toast; 
     } 
    SharedPreferences.Editor editor = app_preferences.edit(); 
     editor.putInt("count", counter); 
    Toast.makeText(this, messageResId, Toast.LENGTH_SHORT).show(); 
    Toast.makeText(this,"Score:" + counter, Toast.LENGTH_SHORT).show(); 
    editor.commit(); 
     } 
/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_quiz); 


    mGeoButton = (Button)findViewById(R.id.geo_button); 
    mGeoButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      counter = 0; 
      Toast.makeText(getApplicationContext(), "Score: 0", 
        Toast.LENGTH_SHORT).show(); 
      mCurrentIndex = 0; 
      updateQuestion(); 
     } 
    }); 

    mSportsButton = (Button)findViewById(R.id.sports_button); 
    mSportsButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      startActivity(intent1); 
     } 
    }); 

    /* mMusicButton = (Button)findViewById(R.id.music_button); 
    mMusicButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      Intent intent = new Intent(this, MusicQuiz.java); 
     } 
    }); */ 

    mTrueButton = (Button)findViewById(R.id.true_button); 
    mTrueButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      checkAnswer(true); 

     } 
    }); 

    mFalseButton = (Button)findViewById(R.id.false_button); 
    mFalseButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      checkAnswer(false); 
      } 
    }); 
    mQuestionTextView = (TextView)findViewById(R.id.question_text_view); 
    ((View) mQuestionTextView) .setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length; 
      updateQuestion(); 
     } 
    }); 
    updateQuestion(); 

    mPreviousButton = (ImageButton)findViewById(R.id.previous_button); 
    ((View) mPreviousButton) .setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
       if (mCurrentIndex != 0) { 
        mCurrentIndex = (mCurrentIndex - 1) % mQuestionBank.length; 
       updateQuestion(); 
       } 
       else { 
        mCurrentIndex = (mCurrentIndex + 4) % mQuestionBank.length; 
       } 
     } 
    }); 
    updateQuestion(); 


    mNextButton = (ImageButton)findViewById(R.id.next_button); 
    ((View) mNextButton).setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 

      mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length; 
      updateQuestion(); 
     } 
     }); 
    updateQuestion(); 

    mResetButton = (Button)findViewById(R.id.reset_button); 
    ((View) mResetButton).setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      counter = 0; 
      Toast.makeText(getApplicationContext(), "Score: 0", 
        Toast.LENGTH_SHORT).show(); 
      mCurrentIndex = 0; 
      updateQuestion(); 
     } 
    }); 
} 




@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.activity_quiz, menu); 
    return true; 
} 

}

Вот лог:

04-04 20:48:42.600: E/AndroidRuntime(25939): FATAL EXCEPTION: main 

04-04 20:48:42.600: E/AndroidRuntime(25939): Process: com.example.geoquizlab1solution, PID: 25939 

04-04 20:48:42.600: E/AndroidRuntime(25939): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.geoquizlab1solution/com.example.geoquizlab1solution.SportsQuiz}: java.lang.NullPointerException 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2124) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2257) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.app.ActivityThread.access$800(ActivityThread.java:139) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.os.Handler.dispatchMessage(Handler.java:102) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.os.Looper.loop(Looper.java:136) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.app.ActivityThread.main(ActivityThread.java:5097) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at java.lang.reflect.Method.invokeNative(Native Method) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at java.lang.reflect.Method.invoke(Method.java:515) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at dalvik.system.NativeStart.main(Native Method) 

04-04 20:48:42.600: E/AndroidRuntime(25939): Caused by: java.lang.NullPointerException 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.content.ContextWrapper.getPackageName(ContextWrapper.java:135) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.content.ComponentName.<init>(ComponentName.java:77) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.content.Intent.<init>(Intent.java:3823) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at com.example.geoquizlab1solution.SportsQuiz.<init>(SportsQuiz.java:28) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at java.lang.Class.newInstanceImpl(Native Method) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at java.lang.Class.newInstance(Class.java:1208) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.app.Instrumentation.newActivity(Instrumentation.java:1084) 

04-04 20:48:42.600: E/AndroidRuntime(25939): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2115) 

04-04 20:48:42.600: E/AndroidRuntime(25939): ... 11 more 

Answer 1

Вы не можете назначить объект, где вы определили ваше Намерение

так поставить эту строку в метод жизненного цикла деятельности, как OnCreate или любой другой,

Просто написать эту линию в методе OnCreate

намерения = новый Намерение (это, SportsQuiz.class); intent1 = getIntent();