我正在做一个 Android 测验。我用一个问题和四个选项以及难度级别创建了我的数据库。我创建了一个布局来显示带有四个按钮的问题。现在的问题是我将如何将我的数据库与问题和四个按钮连接起来。
因此，当我单击右键时，它会移动到下一个问题，当我单击错误的按钮时，它会出错并退出。
XML 中的代码
<?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;
}
}