Android: how to store value for variable in Stringsxml via encoding

Requirement: I need to store the user id and password values ​​as string values ​​in String.xml that are actually accepted by the user.

Problem. As far as I have seen, solutions involve using shared settings. Although I am using Shared Preferences, the values ​​are not stored in String.xml

Here is my Strings.xml

<?xml version="1.0" encoding="utf-8"?>
 <resources>

<string name="app_name">Sp</string>
<string name="hello_world">Hello world!</string>
<string name="menu_settings">Settings</string>
<string name="id" ></string>  <!-- fill in this value from java code, how ? -->
<string name="pwd"></string>  <!-- fill in this value from java code, how ? -->

 </resources> 

      

        
        
        
      

    

page layout: activity_main.xml

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context=".MainActivity" >

 <EditText
     android:id="@+id/text"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:layout_alignParentTop="true"
     android:layout_centerHorizontal="true"
     android:layout_marginTop="178dp"
     android:ems="10"
     android:text="id" >

     <requestFocus />
 </EditText>

 <Button
     android:id="@+id/button"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:layout_below="@+id/editText1"
     android:layout_centerHorizontal="true"
     android:layout_marginTop="44dp"
     android:text="Send" />

 <TextView
     android:id="@+id/textView1"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:layout_alignBottom="@+id/text"
     android:layout_alignParentLeft="true"
     android:layout_marginBottom="40dp"
     android:layout_marginLeft="22dp"
     android:text="id" />



 </RelativeLayout>

      

        
        
        
      

    

EdText.java

import android.app.Activity;

import android.content.SharedPreferences;

import android.content.SharedPreferences.Editor;

import android.os.Bundle;

import android.util.Log;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;


public class EdText extends Activity {

    @Override

    public void onCreate(Bundle savedInstanceState)

    {

       super.onCreate(savedInstanceState);

       setContentView(R.layout.activity_main);


    final EditText et=(EditText)findViewById(R.id.text);


    Button but = (Button) findViewById(R.id.Button);
    but.setOnClickListener(new View.OnClickListener(){

        public void onClick(View arg0) 
        {
            String s1 = ((EditText)findViewById(R.id.text)).getText().toString().trim();

          //Saving your strings
    SharedPreferences prefs = getSharedPreferences("myPrefsKey", Context.MODE_PRIVATE);
    Editor editor = PreferenceManager.getDefaultSharedPreferences(Context).edit();
        editor.putString("s1", s1.getText().toString());
    editor.commit();     



    //retrieving your strings from preferences
    SharedPreferences prefs2 = getSharedPreferences("myPrefsKey",Context.MODE_PRIVATE);
    String s12 = prefs.getString("s12", ""); //empty string is the default value


     }

    });
} }

      

        
        
        
      

    

thank you for your time