Counter variable not updating when switching between views - android-studio

Question

I am trying to create a counter that updates everytime you go back to the main view. The only issue is that everytime I go back to the main view, the counter is getting reset to 1.
package com.example.usingintent2;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
private int counter = 0;
Button btn;
TextView txv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txv = (TextView) findViewById(R.id.counterText);
}
public void onClick(View view) {
startActivity(new Intent("com.example.usingintent2.SecondActivity"));
counter++;
txv = (TextView) findViewById(R.id.counterText);
txv.setText(Integer.toString(counter));
}
public void onStart(){
super.onStart();
counter++;
txv = (TextView) findViewById(R.id.counterText);
txv.setText(Integer.toString(counter));
}
public void onResume(){
super.onResume();
counter++;
txv.setText(Integer.toString(counter));
}
}

Answer 1

You have to use your saveInstanceState Bundle to save your value.
public TextView txv;
private static final String KEY_USERENTRY = "KEY_USERENTRY";
private int counter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txv = (TextView) findViewById(R.id.textView);
txv.setText(Integer.toString(counter));
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(KEY_USERENTRY, yourvalue);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
counter = savedInstanceState.getInt(KEY_USERENTRY);
}
}
yourvalue is the value you want to save.