CODEWITHSUNDEEP
javaandroidandroid-fragmentsorientation
user963241
user963241

Reputation: 7038

Retaining Fragment Data

Following my previous post where I asked about implementing parceable objects, the solution I got was to use setRetainInstance(true); method.

@CommonsWare provided me a sample which I modified as follows:

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <TextView
        android:layout_width="387dp"
        android:layout_height="103dp"
        android:text="New Text"
        android:id="@+id/textView" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Change Text"
        android:id="@+id/button"
        android:layout_gravity="center_horizontal" />

</LinearLayout>

RotationFragmentDemo.java

package com.rotationfragment;

import android.app.Activity;
import android.os.Bundle;

public class RotationFragmentDemo extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // This check returns 'null' for the first time when there are no fragments
        if (getFragmentManager().findFragmentById(android.R.id.content) == null) {

            getFragmentManager().beginTransaction().add(android.R.id.content, new RotationFragment()).commit();
        }
    }
}

RotationFragment.java

package com.rotationfragment;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class RotationFragment extends Fragment implements
        View.OnClickListener {

    TextView textView;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup parent,
                             Bundle savedInstanceState) {

        // This should help to retain fragment
        setRetainInstance(true);

        View result=inflater.inflate(R.layout.activity_main, parent, false);

        result.findViewById(R.id.button).setOnClickListener(this);

        textView = (TextView)result.findViewById(R.id.textView);

        return(result);
    }


    @Override
    public void onClick(View v) {

        textView.setText("Hello.");
    }
}

Upon rotation the text in TextView is not restored.

I know some of you would suggest using parceable writeString parceable method to fix this simple example but I want to know why is the Fragment not retained here using setRetainInstance(true)?

And I don't need to retain a string but Socket, Thread and Activity as in previous post.

Upvotes: 0

Views: 391

Answers (1)

Ajeet Singh
Ajeet Singh

Reputation: 2009

See the answer, "onRetainInstance saves the Fragment object, but I still have to rebuild UI in onCreateView", So you have to restore the state of your views manually

Upvotes: 2

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