这是我的问题代码，我的问题是我无法创建代码从xml中随机输出一个问题而没有任何重复， 这是我的代码：
public class QuizFunActivity extends Activity{
Intent menu = null;
BufferedReader bReader = null;
static JSONArray quesList = null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main2);
Thread thread = new Thread() {
public void run() {
try {
Thread.sleep(3*1000);
finish();
loadQuestions();
Intent intent = new Intent(QuizFunActivity.this, QuestionActivity.class);
QuizFunActivity.this.startActivity(intent);
} catch (Exception e) {
}
}
};
thread.start();
}
private void loadQuestions() throws Exception {
try {
InputStream questions = this.getBaseContext().getResources()
.openRawResource(R.raw.questions);
bReader = new BufferedReader(new InputStreamReader(questions));
StringBuilder quesString = new StringBuilder();
String aJsonLine = null;
while ((aJsonLine = bReader.readLine()) != null) {
quesString.append(aJsonLine);
}
Log.d(this.getClass().toString(), quesString.toString());
JSONObject quesObj = new JSONObject(quesString.toString());
quesList = quesObj.getJSONArray("Questions");
Log.d(this.getClass().getName(),
"Num Questions " + quesList.length());
} catch (Exception e){
} finally {
try {
bReader.close();
} catch (Exception e) {
Log.e("", e.getMessage().toString(), e.getCause());
}
}
}
public static JSONArray getQuesList() {
return quesList;
}
}
你能给我一个关于我的代码中应该创建随机输出代码的部分的样本吗？ 谢谢你的帮助！
您可以查看此活动，
public class QuestionActivity extends Activity {
/** Called when the activity is first created. */
EditText question = null;
RadioButton answer1 = null;
RadioButton answer2 = null;
RadioButton answer3 = null;
RadioButton answer4 = null;
RadioGroup answers = null;
Button finish = null;
int selectedAnswer = -1;
int quesIndex = 0;
int numEvents = 0;
int selected[] = null;
int correctAns[] = null;
boolean review =false;
Button prev, next = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.question);
TableLayout quizLayout = (TableLayout) findViewById(R.id.quizLayout);
quizLayout.setVisibility(android.view.View.INVISIBLE);
try {
question = (EditText) findViewById(R.id.question1);
answer1 = (RadioButton) findViewById(R.id.a0);
answer2 = (RadioButton) findViewById(R.id.a1);
answer3 = (RadioButton) findViewById(R.id.a2);
answer4 = (RadioButton) findViewById(R.id.a3);
answers = (RadioGroup) findViewById(R.id.answers);
RadioGroup questionLayout = (RadioGroup)findViewById(R.id.answers);
Button finish = (Button)findViewById(R.id.finish);
finish.setOnClickListener(finishListener);
prev = (Button)findViewById(R.id.Prev);
prev.setOnClickListener(prevListener);
next = (Button)findViewById(R.id.Next);
next.setOnClickListener(nextListener);
selected = new int[QuizFunActivity.getQuesList().length()];
java.util.Arrays.fill(selected, -1);
correctAns = new int[QuizFunActivity.getQuesList().length()];
java.util.Arrays.fill(correctAns, -1);
this.showQuestion(0,review);
quizLayout.setVisibility(android.view.View.VISIBLE);
} catch (Exception e) {
Log.e("", e.getMessage().toString(), e.getCause());
}
}
private void showQuestion(int qIndex,boolean review) {
try {
JSONObject aQues = QuizFunActivity.getQuesList().getJSONObject(qIndex);
String quesValue = aQues.getString("Question");
if (correctAns[qIndex] == -1) {
String correctAnsStr = aQues.getString("CorrectAnswer");
correctAns[qIndex] = Integer.parseInt(correctAnsStr);
}
question.setText(quesValue.toCharArray(), 0, quesValue.length());
answers.check(-1);
answer1.setTextColor(Color.WHITE);
answer2.setTextColor(Color.WHITE);
answer3.setTextColor(Color.WHITE);
answer4.setTextColor(Color.WHITE);
JSONArray ansList = aQues.getJSONArray("Answers");
String aAns = ansList.getJSONObject(0).getString("Answer");
answer1.setText(aAns.toCharArray(), 0, aAns.length());
aAns = ansList.getJSONObject(1).getString("Answer");
answer2.setText(aAns.toCharArray(), 0, aAns.length());
aAns = ansList.getJSONObject(2).getString("Answer");
answer3.setText(aAns.toCharArray(), 0, aAns.length());
aAns = ansList.getJSONObject(3).getString("Answer");
answer4.setText(aAns.toCharArray(), 0, aAns.length());
Log.d("",selected[qIndex]+"");
if (selected[qIndex] == 0)
answers.check(R.id.a0);
if (selected[qIndex] == 1)
answers.check(R.id.a1);
if (selected[qIndex] == 2)
answers.check(R.id.a2);
if (selected[qIndex] == 3)
answers.check(R.id.a3);
setScoreTitle();
if (quesIndex == (QuizFunActivity.getQuesList().length()-1))
next.setEnabled(false);
if (quesIndex == 0)
prev.setEnabled(false);
if (quesIndex > 0)
prev.setEnabled(true);
if (quesIndex < (QuizFunActivity.getQuesList().length()-1))
next.setEnabled(true);
if (review) {
Log.d("review",selected[qIndex]+""+correctAns[qIndex]);;
if (selected[qIndex] != correctAns[qIndex]) {
if (selected[qIndex] == 0)
answer1.setTextColor(Color.RED);
if (selected[qIndex] == 1)
answer2.setTextColor(Color.RED);
if (selected[qIndex] == 2)
answer3.setTextColor(Color.RED);
if (selected[qIndex] == 3)
answer4.setTextColor(Color.RED);
}
if (correctAns[qIndex] == 0)
answer1.setTextColor(Color.GREEN);
if (correctAns[qIndex] == 1)
answer2.setTextColor(Color.GREEN);
if (correctAns[qIndex] == 2)
answer3.setTextColor(Color.GREEN);
if (correctAns[qIndex] == 3)
answer4.setTextColor(Color.GREEN);
}
} catch (Exception e) {
Log.e(this.getClass().toString(), e.getMessage(), e.getCause());
}
}
private OnClickListener finishListener = new OnClickListener() {
public void onClick(View v) {
setAnswer();
//Calculate Score
int score = 0;
for(int i=0; i<correctAns.length; i++){
if ((correctAns[i] != -1) && (correctAns[i] == selected[i]))
score++;
}
AlertDialog alertDialog;
alertDialog = new AlertDialog.Builder(QuestionActivity.this).create();
alertDialog.setTitle("Score");
alertDialog.setMessage((score) +" out of " + (QuizFunActivity.getQuesList().length()));
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "Retake", new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int which) {
review = false;
quesIndex=0;
QuestionActivity.this.showQuestion(0, review);
}
});
/* alertDialog.setButton(AlertDialog.BUTTON_POSITIVE, "Review", new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int which) {
review = true;
quesIndex=0;
QuestionActivity.this.showQuestion(0, review);
}
}); */
alertDialog.setButton(AlertDialog.BUTTON_NEGATIVE,"Quit", new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int which) {
review = false;
Intent instructionsIntent = new Intent(QuestionActivity.this,MainBookActivity.class);
startActivity(instructionsIntent);
finish();
}
});
alertDialog.show();
}
};
private void setAnswer() {
if (answer1.isChecked())
selected[quesIndex] = 0;
if (answer2.isChecked())
selected[quesIndex] = 1;
if (answer3.isChecked())
selected[quesIndex] = 2;
if (answer4.isChecked())
selected[quesIndex] = 3;
Log.d("",Arrays.toString(selected));
Log.d("",Arrays.toString(correctAns));
}
private OnClickListener nextListener = new OnClickListener() {
public void onClick(View v) {
setAnswer();
quesIndex++;
if (quesIndex >= QuizFunActivity.getQuesList().length())
quesIndex = QuizFunActivity.getQuesList().length() - 1;
showQuestion(quesIndex,review);
}
};
private OnClickListener prevListener = new OnClickListener() {
public void onClick(View v) {
setAnswer();
quesIndex--;
if (quesIndex < 0)
quesIndex = 0;
showQuestion(quesIndex,review);
}
};
private void setScoreTitle() {
this.setTitle("SciQuiz3 " + (quesIndex+1)+ "/" + QuizFunActivity.getQuesList().length());
}
@Override
public void onBackPressed() {
moveTaskToBack(true);
}
}
谢谢！