CODEWITHSUNDEEP
androidsavecontinue
Maduranga E
Maduranga E

Reputation: 1689

how to save and retrive data from the last run of an android application?

I have to create a small android application for my college course work which presents 10 maths problems and take answers from users to calculate the score.

The program is supposed to have a main screen with "new game" button and a "continue" button.

How do I program to save data during the application run and retrieve them from the stored place to continue from that point if the user presses continue button? (what sort of a method I should be looking at for such a task? )

Thanks in advance.

Upvotes: 2

Views: 478

Answers (4)

Karthik
Karthik

Reputation: 5033

Just use preference to store and retrieve value in the code.Here is the snippet

//Set Preference
SharedPreferences myPrefs = getSharedPreferences("myPrefs", MODE_WORLD_READABLE);
SharedPreferences.Editor prefsEditor;  
prefsEditor = myPrefs.edit();  
prefsEditor.putString("REFKEY", valuetobestored);
prefsEditor.commit();

//Get Preferenece  
SharedPreferences myPrefs;  
myPrefs = getSharedPreferences("myPrefs", MODE_WORLD_READABLE);
String output=myPrefs.getString("REFKEY", "");

Upvotes: 1

5hssba
5hssba

Reputation: 8079

May be this is not the best solution.. but this is a way to get required functionality.. in on click of continue button put this code

finish();
                 Intent k=new Intent(youractivitytivity.this,youractivity.class);
k.putExtra("qno",x+1)<---- next question number to appear on screen(x is the present question number)
k.putExtra("score",bool)<--- if the answer is right or wrong)
                 startActivity(k);

then in the on create of your activity.. get extras and check which question you have to display... i think you have an array of 10 questions..

Upvotes: 0

AndreiBogdan
AndreiBogdan

Reputation: 11164

Just use SharedPreferences. Check this link out for more details. 2 early in the morning to give you an example of my own :P

How do I get the SharedPreferences from a PreferenceActivity in Android?

The preferences lasts as long as the application is installed on the device. One you delete if , it removes them as well.

Another cool thing you might want to know, if you want to check if your app is at it's first run, EVER, then just check a boolean value stored (or not stored on the first run) on the device. :) If there isn't one (it will return the default value), then just change it's value to true or something and as you'll check it every time the app runs, you'll know it's not the first run :)

Hope this helps, cheers.

Upvotes: 0

Soham
Soham

Reputation: 4960

It depends on the kind of data you want to store. If it is really basic, you would want to store them as name value pairs in the onSaveInstanceState method or as Preferences in the onPause method, if it is a bit more complex, you might want to store in a SQLiteDB.

The guide says

the method onSaveInstanceState(Bundle) is called before placing the activity in such a background state, allowing you to save away any dynamic instance state in your activity into the given Bundle, to be later received in onCreate(Bundle) if the activity needs to be re-created. See the Process Lifecycle section for more information on how the lifecycle of a process is tied to the activities it is hosting. Note that it is important to save persistent data in onPause() instead of onSaveInstanceState(Bundle) because the latter is not part of the lifecycle callbacks, so will not be called in every situation as described in its documentation.

This is how you save data in onSaveInstanceState: Saving Android Activity state using Save Instance State

This is how you can save data in Preferences: Making data persistent in android

Upvotes: 0

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