Java / Xml / Android-从Java中的.XML字符串文件中调用随机字符串

Question

I'm currently developing android quiz app and I implemented the "reset" button that resets the questions and randomize them, but I'm having trouble with calling the random Strings from .xml file in MainActivity.java.

I have all of my questions listed in the Strings.xml file like this, in order to make them easy to translate:

<string name="q1">The reactor at the site of the Chernobyl nuclear disaster is now in which country?</string>
<string name="a1">A. Slovakia</string>
<string name="b1">B. Ukraine</string>
<string name="c1">C. Hungary</string>
<string name="d1">D. Russia</string>
<string name="q1answer">B</string>

All of the questions are listed in that file like q1, q2, q3, and the same goes for ABCD answers: a1, b1, c1, d1; a2, b2, c2, d2 , and so on.

There are many questions, but button chooses only 5 of them and displays them on the screen. The problem is that I just can't access the Strings if I want to use an integer generated by randomizer to find them in .xml :

    for (int i = 1; i <= 5; i++) {

        // I managed to get the identifier of the TextView with the for loop like that (TextViews for questios are listed q1q, q2q, q3q, q4q, q5q):
        // I would like to do the same thing down there with Strings.
        TextView question = (TextView) findViewById(getResources().getIdentifier("q" + i + "q", "id", this.getPackageName()));

        // randomQuestion is the number of the question in random number generator from different method.
        randomQuestion = randomizeNumbers();

        // And here I'm stuck, this will show "q1-randomNumber" instead of the real question, 
        // because it does not see it as an ID. I tried various different solutions, but nothing works.
        question.setText("q" + randomQuestion);

        // I left the most silly approach to show what I mean.
    }

What can I do to make the computer distinguish the name of the String? So it displays the real question instead of "q1" "q6" "q17"?

Thank you for help in advance!

Answer 1

You can access strings from the string.xml file by using the getIdentifier() utility.

  private String getStringByName(String name) {
  int resId = getResources().getIdentifier(name, "string", getPackageName());
  return getString(resId);
}

It would be a lot easier if you also tried another approach entirely and create a Problem class which would look something like :

public class Problem(){
int ID;
String question;
String answer1; String answer2; //..and so on
String answerCorrect;

public class Problem(int ID, String question, ...){
this.question= question;
... 
}
}

And than, create and ArrayList = new ArrayList<>(); and populate it with your questions. Than, you would have the ability to access them by their ID / position in array, search them by name and so on. In the future, you can use this model to request the list of problems from a server too.

Answer 2

question.setText("q" + randomQuestion);

In here, your parameter is inferred as a string since you pass "q" , so it will display "q-randomNumber" as expected. I think what you want is to pass and actual ID to setText . To do this, you can do the same approach you did to find the question textview ID using "string" instead of "id".

Answer 3

In the MainActivity or in a function :

Resources res = getResources();

        myString = res.getStringArray(R.array.YOURXMLFILE);

        String q = myString[rgenerator.nextInt(myString.length)];
// WE GET THE TEXTVIEW
        tv = (TextView) findViewById(R.id.textView15);
        tv.setText(q);
// WE SET THE TEXTVIEW WITH A RANDOM QUESTION

And declare :

private String[] myString;
private static final Random rgenerator = new Random();
private TextView tv;