我正在创建一个随机引用生成器，但我有一个问题，即引号经常重复是为了使它们不重复？
这是我的MainActivity，提前感谢您的帮助
public class MainActivity extends AppCompatActivity {
private Button addButton;
private TextView displayMessageTextView;
private ArrayList<String> quotes = new ArrayList<String>();
private Random randomGenerator = new Random();
private int previousNumber = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
quotes.add("You smart! You loyal! You're a genious!");
quotes.add("I appreciate you");
quotes.add("This is a major key");
quotes.add("They will try to close the door on U, just open it");
quotes.add("The key to more success is CoCo butter");
quotes.add("Congratulations, you played yourself");
quotes.add("Another one, no. Another two");
quotes.add("I changed... a lot");
quotes.add("They don't want you to jet ski");
quotes.add("The key is to have every key");
quotes.add("Almond milk + Cinnamon Toast Crunch = Major key to success");
quotes.add("Do you see that bamboo? Ain't nothing like bamboo. Blessup");
quotes.add("Bless up. Egg whites, Turkey bacon, Hashbrown, Water");
quotes.add("They wanna come stress me out? Heh, bye");
quotes.add("Lion Order");
quotes.add("Watch your back, but when you get out of the shower dry your back, it's a cold world");
quotes.add("Some of ya'll crabs");
quotes.add("ANOTHA ONE");
quotes.add("We jus seen 2 dolphins");
quotes.add("They don't want you to win");
quotes.add("Be A Star. Be A Superstar");
quotes.add("I remember when I ain't have a jacuzzi");
quotes.add("The other day the grass was brown, now it's green cuz I ain't give up");
quotes.add("In life everyone has a choice. The key is...make a right choice");
quotes.add("We have to get money. We have no choice. It cost money to eat");
quotes.add("I love my bamboo trees. I love fruits. I love apples.");
quotes.add("I told y'all this before, when you have a swimming pool do not use chlorine, use salt water");
quotes.add("The key is: never fold");
quotes.add("major key, get a pedicure and manicure once a week");
quotes.add("They dont want you to be healthy");
quotes.add("To make it thru the jungle you're gonna have to sweat");
quotes.add("They never said winning was easy");
quotes.add("It's important to shape up your hedges. It's like getting a haircut");
quotes.add("LIOOOOON");
quotes.add("To succeed, you must believe. When you believe you will succeed. ");
quotes.add("The key to success is to have a hammock");
quotes.add("Some people can't handle winning. I can.");
quotes.add("They don't want you to have lunch");
quotes.add("It's not an easy road but give thanks to the road");
quotes.add("The key to success is to have a lot of pillows. A lot.");
displayMessageTextView = (TextView) findViewById(R.id.displayMessageTextView);
displayMessageTextView.setText("Press the button to generate a random quote");
addButton = (Button) findViewById(R.id.addObjecttive);
addButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int randomQuoteIndex = getRandomNumber();
String quote = quotes.get(randomQuoteIndex);
displayMessageTextView.setText(quote);
}
});
}
public int getRandomNumber() {
int randomNumber = randomGenerator.nextInt(40);
while (previousNumber == randomNumber) {
randomNumber = randomGenerator.nextInt(40);
}
previousNumber = randomNumber;
return randomNumber;
}
}
答案 0 :(得分：0)
在stackoverflow上有很多关于这个主题的讨论：
Creating random numbers with no duplicates
在您的情况下，以下方法也可能有效：
编辑：
Code cood看起来像这样：
String returnRandomQuote(){
if(quotesCopy==null || quotesCopy.size()==0){
quotesCopy = (ArrayList<String>) quotes.clone();
}
Collections.shuffle(quotesCopy);
String ret = quotesCopy.get(0);
quotesCopy.remove(0);
return ret;
}
答案 1 :(得分：0)
我想到的第一件事就是创建该列表的副本并删除您显示的每个引用。当cpied数组的长度小于某个硬编码值时，你将重新复制原始arrray。
第二个实现相同的工作是将每个选择的引用复制到某个数组，并在每个随机获取后检查它是否存在于此数组中，如果是，则尝试获取另一个。如果该数组的长度将大于某些硬编码值而不是刷新它。
编辑：
您必须创建另一个ArrayList。然后当你接受任何引用时，你检查它是否存在（当然第一个不存在，因为它是空数组）。如果它不存在，则将其添加到副本数组中。所以它不会在短时间内被选中。当保存（显示）的引号数重现一些值（此处为20）时，您清空此数组，以便随机选择可以再次启动将原始列表。如果修改了下面的代码。我不是Java程序员，但应该可以工作。
public class MainActivity extends AppCompatActivity {
private Button addButton;
private TextView displayMessageTextView;
private ArrayList<String> quotes = new ArrayList<String>();
private ArrayList<String> quotes = new ArrayList<String>();
private Random randomGenerator = new Random();
private int previousNumber = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
quotes.add("You smart! You loyal! You're a genious!");
quotes.add("I appreciate you");
quotes.add("This is a major key");
quotes.add("They will try to close the door on U, just open it");
quotes.add("The key to more success is CoCo butter");
quotes.add("Congratulations, you played yourself");
quotes.add("Another one, no. Another two");
quotes.add("I changed... a lot");
quotes.add("They don't want you to jet ski");
quotes.add("The key is to have every key");
quotes.add("Almond milk + Cinnamon Toast Crunch = Major key to success");
quotes.add("Do you see that bamboo? Ain't nothing like bamboo. Blessup");
quotes.add("Bless up. Egg whites, Turkey bacon, Hashbrown, Water");
quotes.add("They wanna come stress me out? Heh, bye");
quotes.add("Lion Order");
quotes.add("Watch your back, but when you get out of the shower dry your back, it's a cold world");
quotes.add("Some of ya'll crabs");
quotes.add("ANOTHA ONE");
quotes.add("We jus seen 2 dolphins");
quotes.add("They don't want you to win");
quotes.add("Be A Star. Be A Superstar");
quotes.add("I remember when I ain't have a jacuzzi");
quotes.add("The other day the grass was brown, now it's green cuz I ain't give up");
quotes.add("In life everyone has a choice. The key is...make a right choice");
quotes.add("We have to get money. We have no choice. It cost money to eat");
quotes.add("I love my bamboo trees. I love fruits. I love apples.");
quotes.add("I told y'all this before, when you have a swimming pool do not use chlorine, use salt water");
quotes.add("The key is: never fold");
quotes.add("major key, get a pedicure and manicure once a week");
quotes.add("They dont want you to be healthy");
quotes.add("To make it thru the jungle you're gonna have to sweat");
quotes.add("They never said winning was easy");
quotes.add("It's important to shape up your hedges. It's like getting a haircut");
quotes.add("LIOOOOON");
quotes.add("To succeed, you must believe. When you believe you will succeed. ");
quotes.add("The key to success is to have a hammock");
quotes.add("Some people can't handle winning. I can.");
quotes.add("They don't want you to have lunch");
quotes.add("It's not an easy road but give thanks to the road");
quotes.add("The key to success is to have a lot of pillows. A lot.");
displayMessageTextView = (TextView) findViewById(R.id.displayMessageTextView);
displayMessageTextView.setText("Press the button to generate a random quote");
addButton = (Button) findViewById(R.id.addObjecttive);
addButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Boolean isDifferent = false;
while(!isDifferent)
{
int randomQuoteIndex = getRandomNumber();
String quote = quotes.get(randomQuoteIndex);
if(!quotesCopy.contains(quote)) {
isDifferent = true;
quotesCopy.add(quote);
}
if(quotesCopy.size() > 20)
quotesCopy = new ArrayList<String>();
}
displayMessageTextView.setText(quote);
}
});
}
public int getRandomNumber() {
int randomNumber = randomGenerator.nextInt(40);
while (previousNumber == randomNumber) {
randomNumber = randomGenerator.nextInt(40);
}
previousNumber = randomNumber;
return randomNumber;
}
}