Question

我正在进行Android测验。我创建了我的数据库，其中包含一个问题和四个选项以及难度级别。我创建了一个布局，用四个按钮显示问题。现在的问题是如何将我的数据库与问题和四个按钮连接起来。

这样，当我点击右键时，它会移动到下一个问题，当我点击错误按钮时会出现错误并退出。

XML格式的代码

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent" android:gravity="center_horizontal"
android:background="@drawable/background">

<LinearLayout android:orientation="horizontal"
      android:layout_width="wrap_content"
    android:layout_height="110dp" 
    android:paddingTop="5dip" android:paddingBottom="5dip"
    android:gravity="center_horizontal">

    <ImageView
        android:id="@+id/logo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingBottom="1dip"
        android:paddingTop="1dip"
        android:src="@drawable/logo2" />

</LinearLayout>

<LinearLayout android:orientation="horizontal"
    android:layout_width="fill_parent" android:layout_height="wrap_content"
    android:paddingTop="5dip" android:paddingBottom="5dip"
    android:gravity="center_horizontal">

    <RadioGroup android:layout_width="fill_parent"
        android:layout_height="wrap_content" android:orientation="vertical"
        android:background="#99CCFF"
        android:id="@+id/group1">

        <TextView android:layout_width="fill_parent"
            android:layout_height="wrap_content"        
            android:background="#0000CC"
            android:textStyle="bold" android:id="@+id/question"/>

        <Button android:onClick="false" android:id="@+id/answer1"
            android:layout_width="150dip" />

        <Button android:onClick="false" android:id="@+id/answer2"
            android:layout_width="150dip" />    
        <Button android:onClick="false" android:id="@+id/answer3" 
            android:layout_width="150dip"/> 
        <Button android:onClick="false" android:id="@+id/answer4"
            android:layout_width="150dip" />    
    </RadioGroup>
</LinearLayout>

我的DBHelper.java

public class DBHelper extends SQLiteOpenHelper{

//The Android's default system path of your application database.

private static String DB_PATH = "/data/data/com.starchazer.cyk/databases/";
private static String DB_NAME = "questionsDb";
private SQLiteDatabase myDataBase; 
private final Context myContext;

/**
 * Constructor
 * Takes and keeps a reference of the passed context in order to access to the application assets and resources.
 * @param context
 */
public DBHelper(Context context) {
    super(context, DB_NAME, null, 1);
    this.myContext = context;
}   

/**
 * Creates a empty database on the system and rewrites it with your own database.
 * */
public void createDataBase() throws IOException{

    boolean dbExist = checkDataBase();
    if(!dbExist)
    {
        //By calling this method and empty database will be created into the default system path
        //of your application so we are gonna be able to overwrite that database with our database.
        this.getReadableDatabase();

        try {
            copyDataBase(); 
        } catch (IOException e) {
            throw new Error("Error copying database");
        }
    }
}

/**
 * Check if the database already exist to avoid re-copying the file each time you open the application.
 * @return true if it exists, false if it doesn't
 */
private boolean checkDataBase(){
    SQLiteDatabase checkDB = null;
    try{
        String myPath = DB_PATH + DB_NAME;
        checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
    }catch(SQLiteException e){
        //database does't exist yet.
    }
    if(checkDB != null){
        checkDB.close();
    }

    return checkDB != null ? true : false;
}

/**
 * Copies your database from your local assets-folder to the just created empty database in the
 * system folder, from where it can be accessed and handled.
 * This is done by transfering bytestream.
 * */
private void copyDataBase() throws IOException{

    //Open your local db as the input stream
    InputStream myInput = myContext.getAssets().open(DB_NAME);

    // Path to the just created empty db
    String outFileName = DB_PATH + DB_NAME;

    //Open the empty db as the output stream
    OutputStream myOutput = new FileOutputStream(outFileName);

    //transfer bytes from the inputfile to the outputfile
    byte[] buffer = new byte[1024];
    int length;
    while ((length = myInput.read(buffer))>0){
        myOutput.write(buffer, 0, length);
    }

    //Close the streams
    myOutput.flush();
    myOutput.close();
    myInput.close();

}

public void openDataBase() throws SQLException{
    //Open the database
    String myPath = DB_PATH + DB_NAME;
    myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}

@Override
public synchronized void close() {
    if(myDataBase != null)
        myDataBase.close();
    super.close();
}

@Override
public void onCreate(SQLiteDatabase db) {
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}

// Add your public helper methods to access and get content from the database.
// You could return cursors by doing "return myDataBase.query(....)" so it'd be easy
// to you to create adapters for your views.




public List<Question> getQuestionSet(int difficulty, int numQ){
    List<Question> questionSet = new ArrayList<Question>();
    Cursor c = myDataBase.rawQuery("SELECT * FROM QUESTIONS WHERE DIFFICULTY=" + difficulty +
            " ORDER BY RANDOM() LIMIT " + numQ, null);
    while (c.moveToNext()){
        //Log.d("QUESTION", "Question Found in DB: " + c.getString(1));
        Question q = new Question();
        q.setQuestion(c.getString(1));
        q.setAnswer(c.getString(2));
        q.setOption1(c.getString(3));
        q.setOption2(c.getString(4));
        q.setOption3(c.getString(5));
        q.setRating(difficulty);
        questionSet.add(q);
    }
    return questionSet;
}
}

我的问题活动

public class QuestionActivity extends Activity implements OnClickListener{

private Question currentQ;
private GamePlay currentGame;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.question);
    /**
     * Configure current game and get question
     */



    currentGame = ((XYZ_Application)getApplication()).getCurrentGame();
    currentQ = currentGame.getNextQuestion();
    Button c1 = (Button) findViewById(R.id.answer1 );
    c1.setOnClickListener(this);
    Button c2 = (Button) findViewById(R.id.answer2 );
    c2.setOnClickListener(this);
    Button c3 = (Button) findViewById(R.id.answer3 );
    c3.setOnClickListener(this);
    Button c4 = (Button) findViewById(R.id.answer4 );
    c4.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)));
}


@Override
public void onClick(View arg0) {


    /**
     * validate a buttonselected has been selected
     */    
    if (!checkAnswer()) return;


    /**
     * check if end of game
     */
    if (currentGame.isGameOver()){


        Intent i = new Intent(this, Main.class);
        startActivity(i);
        finish();
    }
    else{
        Intent i = new Intent(this, QuestionActivity.class);
        startActivity(i);
        finish();
    }
}


@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() {
    String answer = getSelectedAnswer();
    if (answer==null){

        return false;
    }
    else {

        if (currentQ.getAnswer().equalsIgnoreCase(answer))
        {
            //Log.d("Questions", "Correct Answer!");
            currentGame.incrementRightAnswers();
        }
        else{
            //Log.d("Questions", "Incorrect Answer!");
            currentGame.incrementWrongAnswers();
        }
        return true;
    }
}


/**
 * 
 */
private String getSelectedAnswer() {
    Button c1 = (Button)findViewById(R.id.answer1);
    Button c2 = (Button)findViewById(R.id.answer2);
    Button c3 = (Button)findViewById(R.id.answer3);
    Button c4 = (Button)findViewById(R.id.answer4);
    if (c1.callOnClick())
    {
        return c1.getText().toString();
    }
    if (c2.callOnClick())
    {
        return c2.getText().toString();
    }
    if (c3.callOnClick())
    {
        return c3.getText().toString();
    }
    if (c4.callOnClick())
    {
        return c4.getText().toString();
    }

    return null;
}


}

Answer 1

对不起，我不会在这里提供代码。

这就是我要做的当Actvity开始

使用选项从Db加载问题
我更喜欢选项array / arraylist
为每个按钮分配文本选项

添加常见的onclick侦听器，例如this

public void onClick(View v){
int id=v.getId();
String answer=v.getText();
if(answer.equals('ANSWER FROM DB'){
// If right then next question
// Else to MainActivity
    }

/**switch(id){
    case R.id.answer1:
         processAnswer(1);

         break;
    case R.id.answer2:
         processAnswer(2);
         break;
    // So on
    }
 **/
}

processAnswer看起来像

void processAnswer(int option){
// Since I have the option here
// I will check it with Database
// If its correct then next question else exit
}

如何检索按钮上的数据并移动到下一步按钮？

1 个答案: