android - (帮助)java.lang.runtimeException 无法启动 Activity componentinfo

标签 android runtimeexception main-activity

我是编程新手，如果此类问题已经被问过很多次，我很抱歉。 我对这些错误感到很困惑，请帮忙...... 这是我的 MainActivity.java

package id.romi.androidquiz;

import java.util.Collections;
import java.util.List;


import id.romi.androidquiz.entity.Quiz;
import id.romi.androidquiz.util.DBAdapter;
import id.romi.androidquiz.util.Utils;

import com.actionbarsherlock.app.SherlockActivity;



import android.app.AlertDialog;
import android.content.Intent;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends SherlockActivity implements OnClickListener
{
    private static final String TAG = MainActivity.class.getName();

    private TextView    soal, user, txtScore, soalCounter, Timer;
    private Button      btnNext;
    private RadioGroup  rg_answer;
    private RadioButton rb_A, rb_B, rb_C, rb_D;


    private DBAdapter   mDb;
    private List<Quiz>  mListQuiz;
    private Quiz        mQuiz;
    private CountDownTimer  mCountDownTimer;

    private int         mScore;
    private int         mTime = 0;
    private int         currentSoal = 0;
    private static final int    milisecond  = 1000;
    private static final int    second = 90;
    private static final int    detik  = second * milisecond;





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

        //savedInstanceState instance dbAdapter
        mDb = DBAdapter.getInstance(this);

        // get data soal
        mListQuiz = mDb.getAllSoal();

        // acak list 
        Collections.shuffle(mListQuiz);
        setupView();

        // tampilkan input username
        showInputUser();

    }


    private void mulaiQuiz()
    {
        setupSoal();
        setupTimer();
    }

    private void showInputUser()
    {
        LayoutInflater mInflater = LayoutInflater.from(this);
        View v = mInflater.inflate(R.layout.input_user, null);

        final AlertDialog dialog = new AlertDialog.Builder(this).create();

        dialog.setView(v);
        dialog.setTitle("Input Username");

        final Button btnOk = (Button) v.findViewById(R.id.btnOk);
        final EditText inputUser = (EditText) v.findViewById(R.id.inputUser);

        btnOk.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                user.setText(inputUser.getText().toString());
                mulaiQuiz();
                dialog.dismiss();

            }
        });
        dialog.show();

        }

        private void setupTimer()
        {
            mCountDownTimer = new CountDownTimer(detik, 1000)
            {
                @Override
                public void onTick(long millisUntilFinished)
                {
                    // TODO Auto-generated method stub
                    Timer.setText("time: " + millisUntilFinished / 1000 + "detik");
                    mTime = (int) (millisUntilFinished / 1000);
                }

                @Override
                public void onFinish()
                {
                    // TODO Auto-generated method stub
                    Timer.setText("time: 0 detik");
                    Toast.makeText(MainActivity.this, "Waktu Habis", Toast.LENGTH_SHORT).show();
                }
            };
            mCountDownTimer.start();

            }

    private void setupSoal()
    {
        Utils.TRACE(TAG, "Soal ke - " + currentSoal);
        Utils.TRACE(TAG, "Size - " + mListQuiz.size());

        //clear checked radiobutton
        rg_answer.clearCheck();

        //get soal berdasar index
        mQuiz = mListQuiz.get(currentSoal);

        //set counter soal
        soalCounter.setText("Soal ke -" + (currentSoal + 1));
        //set soalnya
        soal.setText(mQuiz.getSoal());

        rb_A.setText("A. " + mQuiz.getJawaban_a());
        rb_B.setText("B. " + mQuiz.getJawaban_b());
        rb_C.setText("C. " + mQuiz.getJawaban_c());
        rb_D.setText("D. " + mQuiz.getJawaban_d());

        currentSoal++;
    }

    private void setupView()
    {
        soal = (TextView) findViewById(R.id.txtSoal);
        soalCounter = (TextView) findViewById(R.id.txtSoalCount);
        txtScore = (TextView) findViewById(R.id.txtScore);
        user = (TextView) findViewById(R.id.txtUser);
        Timer = (TextView) findViewById(R.id.timer);

        txtScore.setText("Score : " + mScore);

        rb_A = (RadioButton) findViewById(R.id.rb_A);
        rb_B = (RadioButton) findViewById(R.id.rb_B);
        rb_C = (RadioButton) findViewById(R.id.rb_C);
        rb_D = (RadioButton) findViewById(R.id.rb_D);
        rg_answer = (RadioGroup) findViewById(R.id.rgAnswer);
        btnNext = (Button) findViewById(R.id.btnNext);

        btnNext.setOnClickListener(this);
    }

    @Override
    public void onClick(View v)
    {
        if (v == btnNext)
        {
            if(getAnswer().equals(mQuiz.getJawaban_benar().toUpperCase()))
            {
                mScore += 10;
                txtScore.setText("Score" + mScore);
                // setupSoal();
            }
            if(currentSoal < mListQuiz.size())
            {
                setupSoal();
            }
            else
            {
                mTime = second - mTime;

                Bundle bundle = new Bundle();
                bundle.putString("user", user.getText().toString());
                bundle.putInt("score", mScore);
                bundle.putInt("time", mTime);

                Intent i = new Intent(MainActivity.this, ResultActivity.class);
                i.putExtras(bundle);
                startActivity(i);
                finish();
            }
            Utils.TRACE(TAG,  "Your score" + mScore);
        }
    }


    private String getAnswer()
    {
        int id = rg_answer.getCheckedRadioButtonId();
        if (id == R.id.rb_A )
        {
        return "A";
        } else if (id == R.id.rb_B )
        {
        return "B";
        } else if (id == R.id.rb_C )
        {
        return "C";
        } else if (id == R.id.rb_D )
        {
        return "D";
        }
        return "";
    }

}

我的AndroidManifest.xml

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

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/Theme.Sherlock.Light" >
        <activity
            android:name="id.romi.androidquiz.MainActivity"
            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:name="id.romi.androidquiz.ResultActivity"
            android:label="@string/title_activity_result"
            ></activity>
    </application>

</manifest>

最后这是我的 logcat

10-28 00:40:52.024: I/SQLiteAssetHelper(807): successfully opened database db_quiz
10-28 00:40:52.034: D/AndroidRuntime(807): Shutting down VM
10-28 00:40:52.034: W/dalvikvm(807): threadid=1: thread exiting with uncaught exception (group=0x41465700)
10-28 00:40:52.054: E/AndroidRuntime(807): FATAL EXCEPTION: main
10-28 00:40:52.054: E/AndroidRuntime(807): java.lang.RuntimeException: Unable to start activity ComponentInfo{id.romi.androidquiz/id.romi.androidquiz.MainActivity}: java.lang.NullPointerException
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.os.Handler.dispatchMessage(Handler.java:99)
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.os.Looper.loop(Looper.java:137)
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.app.ActivityThread.main(ActivityThread.java:5103)
10-28 00:40:52.054: E/AndroidRuntime(807):  at java.lang.reflect.Method.invokeNative(Native Method)
10-28 00:40:52.054: E/AndroidRuntime(807):  at java.lang.reflect.Method.invoke(Method.java:525)
10-28 00:40:52.054: E/AndroidRuntime(807):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
10-28 00:40:52.054: E/AndroidRuntime(807):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-28 00:40:52.054: E/AndroidRuntime(807):  at dalvik.system.NativeStart.main(Native Method)
10-28 00:40:52.054: E/AndroidRuntime(807): Caused by: java.lang.NullPointerException
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.database.sqlite.SQLiteCursor.getColumnIndex(SQLiteCursor.java:178)
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:301)
10-28 00:40:52.054: E/AndroidRuntime(807):  at id.romi.androidquiz.util.DBAdapter.getAllSoal(DBAdapter.java:95)
10-28 00:40:52.054: E/AndroidRuntime(807):  at id.romi.androidquiz.MainActivity.onCreate(MainActivity.java:65)
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.app.Activity.performCreate(Activity.java:5133)
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
10-28 00:40:52.054: E/AndroidRuntime(807):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
10-28 00:40:52.054: E/AndroidRuntime(807):  ... 11 more

我添加我的 DBAdapter.java

package id.romi.androidquiz.util;

import id.romi.androidquiz.entity.Quiz;

import java.util.ArrayList;
import java.util.List;

import com.readystatesoftware.sqliteasset.SQLiteAssetHelper;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;


public class  DBAdapter extends SQLiteAssetHelper {
private static final String DB_NAME ="db_quiz";
private static final int DB_VER = 1;

public static final String TABLE_SOAL ="tb_soal";

public static final String COL_SOAL_ID ="id";
public static final String COL_SOAL_SOAL ="soal";
public static final String COL_SOAL_JAWABAN_A ="jawaban_a";
public static final String COL_SOAL_JAWABAN_B ="soal";
public static final String COL_SOAL_JAWABAN_C ="soal";
public static final String COL_SOAL_JAWABAN_D ="soal";


    private static DBAdapter dbInstance = null;
    private static SQLiteDatabase db;
    private String COL_SOAL_JAWABAN_BENAR;



    private DBAdapter(Context context)
    {
        super(context, DB_NAME, null, DB_VER);
    }


    public static DBAdapter getInstance(Context context)
    {
        if(dbInstance == null)
        {
            dbInstance = new DBAdapter(context);
            db = dbInstance.getWritableDatabase();
        }
        return dbInstance;
    }





     @Override

    public synchronized void close()
    {
        super.close();
        if (dbInstance != null)
        {
            dbInstance.close();
        }
    }



    public List<Quiz> getAllSoal()
    {
        List<Quiz> listSoal = new ArrayList<Quiz>();

        Cursor cursor = db.query(TABLE_SOAL, new String[]
                {
                COL_SOAL_ID,
                COL_SOAL_SOAL,
                COL_SOAL_JAWABAN_A,
                COL_SOAL_JAWABAN_B,
                COL_SOAL_JAWABAN_C,
                COL_SOAL_JAWABAN_D,
                COL_SOAL_JAWABAN_BENAR
                }, null, null, null, null, null, null);


    if (cursor.moveToFirst())
    {
        do
        {
            Quiz quiz = new Quiz();
            quiz.setId(cursor.getInt(cursor.getColumnIndexOrThrow(COL_SOAL_ID)));
            quiz.setSoal(cursor.getString(cursor.getColumnIndexOrThrow(COL_SOAL_SOAL)));
            quiz.setJawaban_a(cursor.getString(cursor.getColumnIndexOrThrow(COL_SOAL_JAWABAN_A)));
            quiz.setJawaban_b(cursor.getString(cursor.getColumnIndexOrThrow(COL_SOAL_JAWABAN_B)));
            quiz.setJawaban_c(cursor.getString(cursor.getColumnIndexOrThrow(COL_SOAL_JAWABAN_C)));
            quiz.setJawaban_d(cursor.getString(cursor.getColumnIndexOrThrow(COL_SOAL_JAWABAN_D)));
            quiz.setJawaban_benar(cursor.getString(cursor.getColumnIndexOrThrow(COL_SOAL_JAWABAN_BENAR)));

            listSoal.add(quiz);
        } while (cursor.moveToNext());
    }
    return listSoal;
}
}

希望大家能帮我解决我的应用问题 它表明错误位于 DBAdapter.java 中的代码: "quiz.setJawaban_benar(cursor.getString(cursor.getColumnIndexOrThrow(COL_SOAL_JAWABAN_BENAR)));" 和 MainActivity.Java 中的代码: "mListQuiz = mDb.getAllSoal();" MainActivity 中的 getAllSoal() 方法取自 DBAdapter.java

最佳答案

`从 logcat 中的这一行开始

10-27 05:30:40.517: E/AndroidRuntime(822): Caused by: java.lang.ClassNotFoundException:
 Didn't find class "android.view.Linearlayout" on path: 
DexPathList[[zip file "/data/app/id.romi.androidquiz-1.apk"],nativeLibraryDirectories=[/data/app-lib/id.romi.androidquiz-1, /system/lib]]

我想说，您可能在 layout 文件中将 LinearLayout 声明为 

<Linearlayout>

什么时候应该

<LinearLayout>

注意两者大写“L”

你的终止标签可能是同样的方式。检查这些并修复它们，如果它们不正确。如果这不是问题，请发布您的 activity_main.xml。

离题

在 onClick() 中，您正在比较 View，但通常最好比较 的 id查看所以它看起来更像这样

 @Override
public void onClick(View v)
{
    int id = v.getId();  // get the id of the View clicked then switch on it below

    switch (id)
    {
       case R.id.btnNext:
          //code if btnNext was clicked
          break;
       case R.id.idOfAnotherView:
          // more code
          break;
       default:
          //default code
          break;

通过这种方式，您可以比较 id，如果您想要的话，它还允许您使用 switch 语句，恕我直言，它看起来比一堆 更干净>if/else 语句(如果您将此代码用于其他View)。

Logcat

Check out this answer on reading your logcat这将对初步的 self 调试有很大帮助，并让您更好地了解当您遇到困难时要发布的代码中最相关的部分是什么。

关于android - (帮助)java.lang.runtimeException 无法启动 Activity componentinfo，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/19626265/

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