我正在制作一款多选游戏。
我有一个字符串的ArrayList，我想从未解答的问题集中删除已回答的问题。我有以下信息：
删除重复元素的最简单方法是将内容添加到Set（不允许重复），然后将Set添加回ArrayList：
List<String> al = new ArrayList<>();
// add elements to al, including duplicates
Set<String> hs = new HashSet<>();
hs.addAll(al);
al.clear();
al.addAll(hs);
但我仍然不知道在我的代码中应用它，
这是我的代码的两个文件
TriviaQuestion.java
public class TriviaQuestion extends Activity {
private int id;
private String question;
private String opta;
private String optb;
private String optc;
private String optd;
private String answer;
public TriviaQuestion(String q, String oa, String ob, String oc, String od, String ans) {
question = q;
opta = oa;
optb = ob;
optc = oc;
optd = od;
answer = ans;
}
public TriviaQuestion() {
id = 0;
question = "";
opta = "";
optb = "";
optc = "";
optd = "";
answer = "";
}
/* public int getId() {
return id;
}*/
public String getQuestion() {
return question;
}
public String getOpta() {
return opta;
}
public String getOptb() {
return optb;
}
public String getOptc() {
return optc;
}
public String getOptd() {
return optd;
}
public String getAnswer() {
return answer;
}
public void setId(int i) {
id = i;
}
public void setQuestion(String q1) {
question = q1;
}
public void setOpta(String o1) {
opta = o1;
}
public void setOptb(String o2) {
optb = o2;
}
public void setOptc(String o3) {
optc = o3;
}
public void setOptd(String o4) {
optd = o4;
}
public void setAnswer(String ans) {
answer = ans;
}
}
和
TriviaQuizHelper.java
public class TriviaQuizHelper extends SQLiteOpenHelper {
Context context;
private static final String DATABASE_NAME = "DATABASEQUIZ";
private static final int DATABASE_VERSION = 17;
private static final String TABLE_NAME = "TRIVIAQUIZ";
private static final String UID = "_UID";
private static final String QUESTION = "QUESTION";
private static final String OPTA = "OPTA";
private static final String OPTB = "OPTB";
private static final String OPTC = "OPTC";
private static final String OPTD = "OPTD";
private static final String ANSWER = "ANSWER";
private static final String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + " ( " + UID + " INTEGER PRIMARY KEY AUTOINCREMENT , " + QUESTION + " VARCHAR(255), " + OPTA + " VARCHAR(255), " + OPTB + " VARCHAR(255), " + OPTC + " VARCHAR(255), " + OPTD + " VARCHAR(255), " + ANSWER + " VARCHAR(255));";
private static final String DROP_TABLE = "DROP TABLE IF EXISTS " + TABLE_NAME;
public TriviaQuizHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.context = context;
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
sqLiteDatabase.execSQL(CREATE_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
sqLiteDatabase.execSQL(DROP_TABLE);
onCreate(sqLiteDatabase);
}
public void allQuestion() {
TriviaQuestion q1 = new TriviaQuestion("Galileo was an Italian astronomer who developed?", "Telescope", "Airoplane", "Electricity", "Train", "Telescope");
this.insert(q1);
TriviaQuestion q2 = new TriviaQuestion("Who is the father of Geometry ?", "Aristotle", "Euclid", "Pythagoras", "Kepler", "Euclid");
this.insert(q2);
TriviaQuestion q3 = new TriviaQuestion("Who was known as Iron man of India ?", "Govind Ballabh Pant", "Jawaharlal Nehru", "Subhash Chandra Bose", "Sardar Vallabhbhai Patel", "Sardar Vallabhbhai Patel");
this.insert(q3);
TriviaQuestion q4 = new TriviaQuestion("The first woman in space was ?", "Valentina Tereshkova", "Sally Ride", "Naidia Comenci", "Tamara Press", "Valentina Tereshkova");
this.insert(q4);
TriviaQuestion q5 = new TriviaQuestion("Who is the Flying Sikh of India ?", "Mohinder Singh", "Joginder Singh", "Ajit Pal Singh", "Milkha singh", "Milkha singh");
this.insert(q5);
TriviaQuestion q6 = new TriviaQuestion("The Indian to beat the computers in mathematical wizardry is", "Ramanujam", "Rina Panigrahi", "Raja Ramanna", "Shakunthala Devi", "Shakunthala Devi");
this.insert(q6);
TriviaQuestion q7 = new TriviaQuestion("Who is Larry Pressler ?", "Politician", "Painter", "Actor", "Tennis player", "Politician");
this.insert(q7);
TriviaQuestion q8 = new TriviaQuestion("Michael Jackson is a distinguished person in the field of ?", "Pop Music", "Jounalism", "Sports", "Acting", "Pop Music");
this.insert(q8);
TriviaQuestion q9 = new TriviaQuestion("The first Indian to swim across English channel was ?", "V. Merchant", "P. K. Banerji", "Mihir Sen", "Arati Saha", "Mihir Sen");
this.insert(q9);
TriviaQuestion q10 = new TriviaQuestion("Who was the first Indian to make a movie?", "Dhundiraj Govind Phalke", " Asha Bhonsle", " Ardeshir Irani", "V. Shantaram", "Dhundiraj Govind Phalke");
this.insert(q10);
TriviaQuestion q11 = new TriviaQuestion("Who is known as the ' Saint of the gutters ?", "B.R.Ambedkar", "Mother Teresa", "Mahatma Gandhi", "Baba Amte", "Mother Teresa");
this.insert(q11);
TriviaQuestion q12 = new TriviaQuestion("Who invented the famous formula E=mc^2", "Albert Einstein", "Galilio", "Sarvesh", "Bill Gates", "Albert Einstein");
this.insert(q12);
TriviaQuestion q13 = new TriviaQuestion("Who is elected as president of us 2016", "Donald Trump", "Hilary Clinton", "Jhon pol", "Barack Obama", "Donald Trump");
this.insert(q13);
TriviaQuestion q14 = new TriviaQuestion("Who was the founder of company Microsoft", "Bill Gates", "Bill Clinton", "Jhon rio", "Steve jobs", "Bill Gates");
this.insert(q14);
TriviaQuestion q15 = new TriviaQuestion("Who was the founder of company Apple ?", "Steve Jobs", "Steve Washinton", "Bill Gates", "Jobs Wills", "Steve Jobs");
this.insert(q15);
TriviaQuestion q16 = new TriviaQuestion("Who was the founder of company Google ?", "Steve Jobs", "Bill Gates", "Larry Page", "Sundar Pichai", "Larry Page");
this.insert(q16);
TriviaQuestion q17 = new TriviaQuestion("Who is know as god of cricket ?", "Sachin Tendulkar", "Kapil Dev", "Virat Koli", "Dhoni", "Sachin Tendulkar");
this.insert(q17);
TriviaQuestion q18 = new TriviaQuestion("who has won ballon d'or of 2015 ?", "Lionel Messi", "Cristiano Ronaldo", "Neymar", "Kaka", "Lionel Messi");
this.insert(q18);
TriviaQuestion q19 = new TriviaQuestion("who has won ballon d'or of 2014 ?", "Neymar", "Lionel Messi", "Cristiano Ronaldo", "Kaka", "Cristiano Ronaldo");
this.insert(q19);
TriviaQuestion q20 = new TriviaQuestion("the Founder of the most famous gaming platform steam is ?", "Bill Cliton", "Bill Williams", "Gabe Newell", "Bill Gates", "Gabe Newell");
this.insert(q20);
}
public void insert(TriviaQuestion triviaQuestion) {
ContentValues contentvalues = new ContentValues();
/* contentvalues.put(UID,triviaQuestion.getId());*/
contentvalues.put(QUESTION, triviaQuestion.getQuestion());
contentvalues.put(OPTA, triviaQuestion.getOpta());
contentvalues.put(OPTB, triviaQuestion.getOptb());
contentvalues.put(OPTC, triviaQuestion.getOptc());
contentvalues.put(OPTD, triviaQuestion.getOptd());
contentvalues.put(ANSWER, triviaQuestion.getAnswer());
SQLiteDatabase db = this.getWritableDatabase();
db.insert(TABLE_NAME, null, contentvalues);
}
public List<TriviaQuestion> getAllQuestion() {
List<TriviaQuestion> que = new ArrayList<>();
SQLiteDatabase db = this.getWritableDatabase();
String coloumns[] = {UID, QUESTION, OPTA, OPTB, OPTC, OPTD, ANSWER};
Cursor cursor = db.query(TABLE_NAME, coloumns, null, null, null, null, null);
while (cursor.moveToNext()) {
TriviaQuestion triviaQuestion = new TriviaQuestion();
triviaQuestion.setId(cursor.getInt(0));
triviaQuestion.setQuestion(cursor.getString(1));
triviaQuestion.setOpta(cursor.getString(2));
triviaQuestion.setOptb(cursor.getString(3));
triviaQuestion.setOptc(cursor.getString(4));
triviaQuestion.setOptd(cursor.getString(5));
triviaQuestion.setAnswer(cursor.getString(6));
que.add(triviaQuestion);
}
Collections.shuffle(que);
cursor.close();
return que;
}
}
答案 0 :(得分：0)
你应该在TriviaQuestion中添加布尔值＆＃39; isAnswered＆＃39;与吸气剂和setter并取ArrayList＆lt; TriviaQuestion＆GT;列表。
现在您可以按list.get(position).setIsAnswered(true)更新对象了。