CODEWITHSUNDEEP
javaandroid
Harshad Loya
Harshad Loya

Reputation: 123

Missing TextView data(text) in a fragment

I have a few edittexts and textviews in Fragment A. I use edittexts to get value from user and then I calculate based on my formula and show the result in the textview.

For example Edittext A has 1 and Edittext B has 2 and my formula is add so the textview will show the result as 3.

Also, there is a button, info on the Fragment A. On clicking this button a new fragment B is displayed using the below code:

FragmentTransaction fragmentTransaction = 
fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.contentFrag, fragment);
fragmentTransaction.addToBackStack(backStackStateName);
fragmentTransaction.commit();

Now, when I press the back button, I let the system call super.onBackPressed() so that the current Fragment B is removed and I get back Fragment A.

MY PROBLEM:

Now the edittexts retain all their values, however the value I calculated and displayed on TextViews disappears.

I checked onViewStateRestored(Bundle savedInstanceState) method however the parameter savedInstanceState is null.

My Question:

How do I save/retrieve the values for my textviews?

OR

where can I call that code again that calculates the data for textviews ??

Upvotes: 1

Views: 100

Answers (2)

Serg Burlaka
Serg Burlaka

Reputation: 2496

To resolve this problem you need use some data layer like Shared Preference or SQL storage. In some primitive way it looks like:

 public override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
                                     savedInstanceState: Bundle?): View? {

        return inflater?.inflate(R.layout.fragment_blank, container, false)

        //update you UI from local STORAGE on create
        textView.text = sharedPreference.getInt("result_data", 0).toString()//make request local for date


        //calling your calculation
        button.setOnClickListener {

            calculateData(dataInput, object : Callback {
                override fun onCalculated() {

                    //update you UI from local STORAGE layer in MAIN THREAD
                    Handler(Looper.getMainLooper()).post {
                        textView.text = sharedPreference.getInt( 
                                  "result_data",0
                          ).toString()
                    }
                }

            })
        }
    }

//you calculate and request to data layer

    private fun calculateData(inPutData:Int, callback:Callback){

           //use background for calculate It will be available. 
           Thread{

                //calculate
                val result = inPutData+ ARG_PARAM 

                //save result in LOCAL STORAGE
                sharedPreference.edit().putInt( " result", result).apply()

               //update UI 
               callback.onCalculated()

            }.start()

        }

    interface Callback{
        fun onCalculated()

    }

Think also about MVP and Presenter. It is also be available. In open source you can find amazing MVP library called moxy. It can restore your view state.

Upvotes: 1

Murtaza Agaz
Murtaza Agaz

Reputation: 69

Using SharedPreferences will solve your issue just save them in sharedPreferences and clear SharedPreference after Use.

Upvotes: 0

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