Java 无法启动活动？

在添加异步任务之前，我在代码中做了一些更改。我的应用程序工作正常，从远程服务器验证用户名和密码，但当登录成功消息消失时，无法启动其他活动。有人建议我现在添加异步任务，但当我输入正确的用户名和密码时，它就停止工作了。当我输入错误的用户名和密码时，它的工作状态会显示错误的用户名和密码消息。如果有人知道会发生什么错误，请帮助我

代码-

问题活性-

public class QuestionActivity extends Activity implements OnClickListener{

    private Question currentQ;
    private GamePlay currentGame;
    private CountDownTimer counterTimer;

            @Override
            public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.question);
                processScreen();
         }
                /**
         * Configure current game and get question
         */
         private void processScreen()
         {
        currentGame = ((CYKApplication)getApplication()).getCurrentGame();
        currentQ = currentGame.getNextQuestion();
        Button nextBtn1 = (Button) findViewById(R.id.answer1);
        nextBtn1.setOnClickListener(this);
        Button nextBtn2 = (Button) findViewById(R.id.answer2);
        nextBtn2.setOnClickListener(this);
        Button nextBtn3 = (Button) findViewById(R.id.answer3);
        nextBtn3.setOnClickListener(this);
        Button nextBtn4 = (Button) findViewById(R.id.answer4);
        nextBtn4.setOnClickListener(this);
        Button nextBtn5 = (Button) findViewById(R.id.answer5);
        nextBtn5.setOnClickListener(this);
        /**
         * Update the question and answer options..
         */
        setQuestions();

    }


    /**
     * Method to set the text for the question and answers from the current games
     * current question
     */
    private void setQuestions() {
        //set the question text from current question
        String question = Utility.capitalise(currentQ.getQuestion());
        TextView qText = (TextView) findViewById(R.id.question);
        qText.setText(question);

        //set the available options
        List<String> answers = currentQ.getQuestionOptions();
        TextView option1 = (TextView) findViewById(R.id.answer1);
        option1.setText(Utility.capitalise(answers.get(0)));

        TextView option2 = (TextView) findViewById(R.id.answer2);
        option2.setText(Utility.capitalise(answers.get(1)));

        TextView option3 = (TextView) findViewById(R.id.answer3);
        option3.setText(Utility.capitalise(answers.get(2)));

        TextView option4 = (TextView) findViewById(R.id.answer4);
        option4.setText(Utility.capitalise(answers.get(3)));

        int score = currentGame.getScore();
        String scr = String.valueOf(score);
        TextView score1 = (TextView) findViewById(R.id.score);
        score1.setText(scr);

        counterTimer=new CountDownTimer(15000, 1000) {
            public void onFinish() {                
                if(currentGame.getRound()==20)
                    System.exit(0);
                currentGame.decrementScore();
                processScreen();
                             }

            public void onTick(long millisUntilFinished) {
                TextView time = (TextView) findViewById(R.id.timers);
                time.setText( ""+millisUntilFinished/1000);
                                }
        };
        counterTimer.start();
    }


    @Override
    public void onResume() {
        super.onResume();
    }


    @Override
    public void onClick(View arg0) {
        //Log.d("Questions", "Moving to next question");
        if(arg0.getId()==R.id.answer5)
        {
        new AlertDialog.Builder(this)
        .setMessage("Are you sure?")
        .setCancelable(true)
        .setPositiveButton("Yes",
         new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog,
         int id) {
                finish();
                 }
             }).setNegativeButton("No", null).show();

                }

        else
        {
            if(!checkAnswer(arg0)) return;  

        /**
         * check if end of game
         */
        if (currentGame.isGameOver()){
            //Log.d("Questions", "End of game! lets add up the scores..");
            //Log.d("Questions", "Questions Correct: " + currentGame.getRight());
            //Log.d("Questions", "Questions Wrong: " + currentGame.getWrong());
            Intent i = new Intent(this, EndgameActivity.class);
            startActivity(i);
            finish();
        }
            else
            {
            Intent i = new Intent(this, QuestionActivity.class);
                        finish();
                        startActivity(i);
        }
        }
      }



    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event)
    {
        switch (keyCode)
        {
        case KeyEvent.KEYCODE_BACK :
            return true;
        }

        return super.onKeyDown(keyCode, event);
    }


    /**
     * Check if a checkbox has been selected, and if it
     * has then check if its correct and update gamescore
     */
    private boolean checkAnswer(View v) {
        final Button b = (Button) v;
        String answer = b.getText().toString();
         counterTimer.cancel();
         b.setBackgroundResource(R.drawable.ans);
         b.setEnabled(false);
        //Log.d("Questions", "Valid Checkbox selection made - check if correct");
            if (currentQ.getAnswer().equalsIgnoreCase(answer))
                {
                b.setBackgroundResource(R.drawable.ansgreen);
                //Log.d("Questions", "Correct Answer!");
                currentGame.incrementScore();
                }

            else{
                b.setBackgroundResource(R.drawable.ansred);
                //Log.d("Questions", "Incorrect Answer!");
                currentGame.decrementScore1();
                            }
            return true;
        }

}

公共类QuestionActivity扩展活动实现OnClickListener{
私人问题；
私人游戏；
私人倒计时计数器；
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.question）；
processScreen（）；
}
/**
*配置当前游戏并获取问题
*/
私有void processScreen（）
{
currentGame=（（CykaApplication）getApplication（））.getCurrentGame（）；
currentQ=currentGame.getNextQuestion（）；
按钮nextBtn1=（按钮）findViewById（R.id.answer1）；
nextBtn1.setOnClickListener（这个）；
按钮nextBtn2=（按钮）findViewById（R.id.answer2）；
nextBtn2.setOnClickListener（此）；
按钮nextBtn3=（按钮）findViewById（R.id.answer3）；
nextBtn3.setOnClickListener（这个）；
按钮nextBtn4=（按钮）findViewById（R.id.answer4）；
nextBtn4.setOnClickListener（这个）；
按钮nextBtn5=（按钮）findViewById（R.id.answer5）；
nextBtn5.setOnClickListener（此）；
/**
*更新问题和答案选项。。
*/
设置问题（）；
}
/**
*方法为当前游戏中的问题和答案设置文本
*当前问题
*/
私人问题{
//从当前问题设置问题文本
字符串question=Utility.capitalize（currentQ.getQuestion（））；
TextView qText=（TextView）findViewById（R.id.question）；
qText.setText（问题）；
//设置可用选项
列表答案=currentQ.getQuestionOptions（）；
TextView选项1=（TextView）findViewById（R.id.answer1）；
选项1.setText（Utility.capitalize（answers.get（0））；
TextView选项2=（TextView）findViewById（R.id.answer2）；
选项2.setText（Utility.capitalize（answers.get（1））；
TextView选项3=（TextView）findViewById（R.id.answer3）；
选项3.setText（实用程序.大写（答案.获取（2））；
TextView选项4=（TextView）findViewById（R.id.answer4）；
选项4.setText（实用程序.capitalize（answers.get（3））；
int score=currentGame.getScore（）；
String scr=String.valueOf（分数）；
TextView得分1=（TextView）findViewById（R.id.score）；
得分1.setText（scr）；
计数器计时器=新的倒计时（15000，1000）{
public void onFinish（）{
如果（currentGame.getRound（）==20）
系统出口（0）；
currentGame.decrementScore（）；
processScreen（）；
}
公共void onTick（长毫秒未完成）{
TextView时间=（TextView）findViewById（R.id.timers）；
time.setText（“+millisuntillfinished/1000）；
}
};
counterTimer.start（）；
}
@凌驾
恢复时公开作废（）{
super.onResume（）；
}
@凌驾
公共void onClick（视图arg0）{
//日志d（“问题”，“转到下一个问题”）；
if（arg0.getId（）==R.id.answer5）
{
新建AlertDialog.Builder（此）
.setMessage（“您确定吗？”）
.setCancelable（真）
.setPositiveButton（“是”，
新建DialogInterface.OnClickListener（）{
公共void onClick（对话框接口对话框，
int id）{
完成（）；
}
}).setNegativeButton（“否”，null）.show（）；
}
其他的
{
如果（！checkAnswer（arg0））返回；
/**
*检查游戏是否结束
*/
if（currentGame.isGameOver（））{
//Log.d（“问题”，“游戏结束！让我们把分数加起来…”）；
//Log.d（“问题”，“问题正确：”+currentGame.getRight（））；
//Log.d（“问题”，“问题错误：+currentGame.getError（））；
意向i=新意向（此，EndgameActivity.class）；
星触觉（i）；
完成（）；
}
其他的
{
意图i=新意图（此，QuestionActivity.class）；
完成（）；
星触觉（i）；
}
}
}
@凌驾
公共布尔onKeyDown（int-keyCode，KeyEvent事件）
{
开关（钥匙代码）
{
case KeyEvent.KEYCODE\u返回：
返回true；
}
返回super.onKeyDown（keyCode，event）；
}
/**
*检查是否选中了复选框，以及
*然后检查其是否正确并更新游戏分数
*/
私有布尔校验应答（视图v）{
最终按钮b=（按钮）v；
字符串应答=b.getText（）.toString（）；
计数器。取消（）；
b、 挫折资源（R.drawable.ans）；
b、 setEnabled（假）；
//日志d（“问题”，“选中有效复选框-检查是否正确”）；
if（currentQ.getAnswer（）.equalsIgnoreCase（answer））
{
b、 挫折资源（R.drawable.ansgreen）；
//Log.d（“问题”，“正确答案！”）；
currentGame.incrementScore（）；
}
否则{
b、 挫折资源（R.drawable.ansred）；
//Log.d（“
09-24 07:59:32.818: E/AndroidRuntime(17602): FATAL EXCEPTION: main
09-24 07:59:32.818: E/AndroidRuntime(17602): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.abc.cyk/com.abc.cyk.QuestionActivity}: java.lang.NullPointerException
09-24 07:59:32.818: E/AndroidRuntime(17602):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at android.os.Handler.dispatchMessage(Handler.java:99)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at android.os.Looper.loop(Looper.java:137)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at android.app.ActivityThread.main(ActivityThread.java:5041)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at java.lang.reflect.Method.invokeNative(Native Method)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at java.lang.reflect.Method.invoke(Method.java:511)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at dalvik.system.NativeStart.main(Native Method)
09-24 07:59:32.818: E/AndroidRuntime(17602): Caused by: java.lang.NullPointerException
09-24 07:59:32.818: E/AndroidRuntime(17602):    at com.abc.cyk.QuestionActivity.processScreen(QuestionActivity.java:41)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at com.abc.cyk.QuestionActivity.onCreate(QuestionActivity.java:33)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at android.app.Activity.performCreate(Activity.java:5104)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
09-24 07:59:32.818: E/AndroidRuntime(17602):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
09-24 07:59:32.818: E/AndroidRuntime(17602):    ... 11 more
09-24 07:59:38.557: I/Process(17602): Sending signal. PID: 17602 SIG: 9

public class QuestionActivity extends Activity implements OnClickListener{

    private Question currentQ;
    private GamePlay currentGame;
    private CountDownTimer counterTimer;

            @Override
            public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.question);
                processScreen();
         }
                /**
         * Configure current game and get question
         */
         private void processScreen()
         {
        currentGame = ((CYKApplication)getApplication()).getCurrentGame();
        currentQ = currentGame.getNextQuestion();
        Button nextBtn1 = (Button) findViewById(R.id.answer1);
        nextBtn1.setOnClickListener(this);
        Button nextBtn2 = (Button) findViewById(R.id.answer2);
        nextBtn2.setOnClickListener(this);
        Button nextBtn3 = (Button) findViewById(R.id.answer3);
        nextBtn3.setOnClickListener(this);
        Button nextBtn4 = (Button) findViewById(R.id.answer4);
        nextBtn4.setOnClickListener(this);
        Button nextBtn5 = (Button) findViewById(R.id.answer5);
        nextBtn5.setOnClickListener(this);
        /**
         * Update the question and answer options..
         */
        setQuestions();

    }


    /**
     * Method to set the text for the question and answers from the current games
     * current question
     */
    private void setQuestions() {
        //set the question text from current question
        String question = Utility.capitalise(currentQ.getQuestion());
        TextView qText = (TextView) findViewById(R.id.question);
        qText.setText(question);

        //set the available options
        List<String> answers = currentQ.getQuestionOptions();
        TextView option1 = (TextView) findViewById(R.id.answer1);
        option1.setText(Utility.capitalise(answers.get(0)));

        TextView option2 = (TextView) findViewById(R.id.answer2);
        option2.setText(Utility.capitalise(answers.get(1)));

        TextView option3 = (TextView) findViewById(R.id.answer3);
        option3.setText(Utility.capitalise(answers.get(2)));

        TextView option4 = (TextView) findViewById(R.id.answer4);
        option4.setText(Utility.capitalise(answers.get(3)));

        int score = currentGame.getScore();
        String scr = String.valueOf(score);
        TextView score1 = (TextView) findViewById(R.id.score);
        score1.setText(scr);

        counterTimer=new CountDownTimer(15000, 1000) {
            public void onFinish() {                
                if(currentGame.getRound()==20)
                    System.exit(0);
                currentGame.decrementScore();
                processScreen();
                             }

            public void onTick(long millisUntilFinished) {
                TextView time = (TextView) findViewById(R.id.timers);
                time.setText( ""+millisUntilFinished/1000);
                                }
        };
        counterTimer.start();
    }


    @Override
    public void onResume() {
        super.onResume();
    }


    @Override
    public void onClick(View arg0) {
        //Log.d("Questions", "Moving to next question");
        if(arg0.getId()==R.id.answer5)
        {
        new AlertDialog.Builder(this)
        .setMessage("Are you sure?")
        .setCancelable(true)
        .setPositiveButton("Yes",
         new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog,
         int id) {
                finish();
                 }
             }).setNegativeButton("No", null).show();

                }

        else
        {
            if(!checkAnswer(arg0)) return;  

        /**
         * check if end of game
         */
        if (currentGame.isGameOver()){
            //Log.d("Questions", "End of game! lets add up the scores..");
            //Log.d("Questions", "Questions Correct: " + currentGame.getRight());
            //Log.d("Questions", "Questions Wrong: " + currentGame.getWrong());
            Intent i = new Intent(this, EndgameActivity.class);
            startActivity(i);
            finish();
        }
            else
            {
            Intent i = new Intent(this, QuestionActivity.class);
                        finish();
                        startActivity(i);
        }
        }
      }



    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event)
    {
        switch (keyCode)
        {
        case KeyEvent.KEYCODE_BACK :
            return true;
        }

        return super.onKeyDown(keyCode, event);
    }


    /**
     * Check if a checkbox has been selected, and if it
     * has then check if its correct and update gamescore
     */
    private boolean checkAnswer(View v) {
        final Button b = (Button) v;
        String answer = b.getText().toString();
         counterTimer.cancel();
         b.setBackgroundResource(R.drawable.ans);
         b.setEnabled(false);
        //Log.d("Questions", "Valid Checkbox selection made - check if correct");
            if (currentQ.getAnswer().equalsIgnoreCase(answer))
                {
                b.setBackgroundResource(R.drawable.ansgreen);
                //Log.d("Questions", "Correct Answer!");
                currentGame.incrementScore();
                }

            else{
                b.setBackgroundResource(R.drawable.ansred);
                //Log.d("Questions", "Incorrect Answer!");
                currentGame.decrementScore1();
                            }
            return true;
        }

}

startActivity(new Intent(this, QuestionnActivity.class));

startActivity(new Intent(LoActivity.this, QuestionnActivity.class));