通过两项活动维护活动状态

Question

We have and Android App that contains two Activities MainActivity and PageTwo. In the MainActivity we have an EditText widget set to accept number input only and a Button that goes to the next activity with the aid of an Intent. On the second activity PageTwo we have a Button that returns the user to the MainActivity with an Intent. When we enter a value in the EditText field and make the trip from the MainActivity to PageTwo activity and back the value is seemingly erased unless you use the device (emulator) back button. I am trying to maintain the Activity State of this one EditText variable

code snippets

 EditText ETage;
 int vAGE;
 static final String V_AGE = "vAGE"; //KeyValue Pair

@Override
public void onSaveInstanceState(Bundle outState){
    outState.putInt(V_AGE,vAGE);
    super.onSaveInstanceState(outState);
}

//@Override
public void onRestoreInstanceState(Bundle savedInstanceState){
    super.onRestoreInstanceState(savedInstanceState);
    vAGE = savedInstanceState.getInt(V_AGE);
    ETage.setText(String.valueOf(vAGE));
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //if(savedInstanceState != null){
        //vAGE = savedInstanceState.getChar(V_AGE);
    //}
    setContentView(R.layout.activity_main);

  ETage = (EditText)findViewById(R.id.editTextAge); 

Answer 1

if you want to go back to previous Activity why you are calling intent? just simply write onBackPressed(); inside onClick

Example

btn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        onBackPressed();
    }
});

or if you really wanted to use intent you can always use finish() .

Example

btn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

        Intent i = new Intent(PageTwo.this, MainActivity.class);            
        startActivity(i);
        finish();
    }
});

Answer 2

In PageTwo second activity don't return to MainActivity with an intent. Simply, do following in button click:

super.onBackPressed(); // this instead of intent to start MainActivity

Answer 3

From what I understand from your question you can do like this in second page:

@Override
public void onBackPressed() {
    super.onBackPressed();

Intent intent = new   Intent(SecondActivity.this,MainActivity.class);
        startActivity(intent);

}