How to make it from vertical to horizontal view

Question

When I activate the start time I would like to see the number being increased during the time when I change from mobile landscape from vertical to horizontal and from horizontal to vertical.

Obstacle:
When the number displayed with increased value and I want to change the mobile landscape from vertical to horizontal view. When I did itthe numbers go back from scratch.

Today, I'm newbie in android and the source code below doesn't work to make it.

What part am I missing?

--------------------------
class StopwatchActivity





package com.jfdimarzio.stopwatch4;

import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class StopwatchActivity extends AppCompatActivity {

    private int seconds = 0;
    private boolean running;
    private boolean wasRunning;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_stopwatch);

        if(savedInstanceState != null)
        {
            seconds = savedInstanceState.getInt("Seconds");
            running = savedInstanceState.getBoolean("running");
            wasRunning = savedInstanceState.getBoolean("wasRunning");
        }

        runTimer();
    }

    @Override
    public void onSaveInstanceState(Bundle savedInstanceState)
    {
        savedInstanceState.putInt("seconds", seconds);
        savedInstanceState.putBoolean("running", running);
        savedInstanceState.putBoolean("wasRunning", wasRunning);
    }

    @Override
    protected void onStop()
    {
        super.onStop();
        wasRunning = running;
        running = false;
    }

    @Override
    protected void onStart()
    {
        super.onStart();
        if(wasRunning)
        {
            running = true;
        }
    }


    @Override
    protected void onPause()
    {
        super.onPause();
        wasRunning = running;
        running = false;
    }


    @Override
    protected void onResume()
    {
        super.onResume();
        if (wasRunning) {
            running = true;
        }
    }



    public void onClickStart(View view)
    {
        running = true;
    }

    public void onClickStop(View view)
    {
        running = false;
    }

    public void onClickReset(View view)
    {
        running = false;
        seconds= 0;
    }


    private void runTimer()
    {
        final TextView timeView = (TextView)findViewById(R.id.time_view);
        final Handler handler = new Handler();
        handler.post(new Runnable()
        {
            @Override
            public void run()
            {
                int hours = seconds/3600;
                int minutes = (seconds%3600)/60;
                int secs = seconds%60;
                String time = String.format("%d:%02d:%02d", hours, minutes, secs);
                timeView.setText(time);

                if(running)
                {
                    seconds++;
                }

                handler.postDelayed(this, 1000);
            }

        });

    }



}



------------------------------
activity_stopwatch.xml




<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_stopwatch"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.jfdimarzio.stopwatch4.StopwatchActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:id="@+id/textView" />

    <TextView
        android:id="@+id/time_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="0dp"
        android:text=""
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:textSize="92sp" />

    <Button
        android:id="@+id/start_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/time_view"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        android:onClick="onClickStart"
        android:text="@string/start" />

    <Button
        android:id="@+id/stop_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/start_button"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="10dp"
        android:onClick="onClickStop"
        android:text="@string/stop" />

    <Button
        android:id="@+id/reset_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/stop_button"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="10dp"
        android:onClick="onClickReset"
        android:text="@string/reset" />


</RelativeLayout>




------------------------------
strings.xml




<resources>
    <string name="app_name">Stopwatch4</string>
    <string name="start">Start</string>
    <string name="stop">Stop</string>
    <string name="reset">Reset</string>
</resources>

Answer 1

You use savedInstanceState.putInt("seconds") but savedInstanceState.getInt("Seconds"); Change "Seconds" to "seconds" inside the onCreate().

Hope this help, I'm new to StackOverFlow.

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_stopwatch);

    if(savedInstanceState != null)
    {
        seconds = savedInstanceState.getInt("seconds");
        running = savedInstanceState.getBoolean("running");
        wasRunning = savedInstanceState.getBoolean("wasRunning");
    }

    runTimer();
}