How to display Activity only one time?

Question

I'm developing a quiz app. The situation is:

• The user chooses a quiz by touching a button, that opens a new Activity. Inside of this activity the user has to write something on a TextView and than press another button to see if the text is right. If it is right, then another last activity is opened.

• At the moment, when the user returns back to the main activity, where he has to choose the quiz, if he chooses the same quiz he has to write down the answer again.

I need to find a way to save the answer, so that the app doesn't display the activity where he has to write down the answer anymore. It should jump immediately to the last activity. I know I can manage this using SharedPreferences, but i don't know ho to set it up.

Answer 1

First, add these methods - used to write to and read from the SharedPreference:

public String getAnswer()
{
   SharedPreferences sp = getSharedPreferences("prefName",0);
   return sp.getString("myAnswer1","TheDefaultValueIfNoAnswerHasBeenSet");
}

public void setAnswer(String theAnswer)
{
   SharedPreferences.Editor editor = getSharedPreferences("prefName",0).edit();
   editor.putString("myAnswer1", theAnswer);
   editor.commit();
}

Then, when the user returns back to the main activity (you can use the onBackPressed method to check when the activity is closing), you can write the answer to the preference.

For example, in your quiz activity:

@Override
public void onBackPressed() {
    setAnswer(/* the String answer the user currently has */);
}

And then when you are opening your quiz activity, you can read from the SharedPreference.

For example, in your onCreate method:

String previousAnswer = getAnswer();

// check to see if the answer is not "TheDefaultValueIfNoAnswerHasBeenSet"
// or whatever you set the default value to be

// set the answer in the quiz to be previousAnswer