I have a countdown timer app, but I need it to be able to run and count down even if the app is closed. I have been trying to learn SharedPreferences from youtube tutorials but I can't figure out how to get it to work. Are there easier options than SharedPreferences or could someone help me out with it? I've put my countdown timer code down below.
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<EditText
android:id="@+id/editText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="100dp"
android:ems="10"
android:hint="Aeg"
android:inputType="number"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
app:layout_constraintBottom_toTopOf="@+id/textView"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/editText" />
</androidx.constraintlayout.widget.ConstraintLayout>
package com.example.countdowntimerproov1;
import androidx.appcompat.app.AppCompatActivity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.text.DecimalFormat;
import java.text.NumberFormat;
public class MainActivity extends AppCompatActivity {
TextView textView;
Button button;
EditText editText;
long millisUntilFinished;
int finalValue;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = findViewById(R.id.textView);
button = findViewById(R.id.button);
editText = findViewById(R.id.editText);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String value = editText.getText().toString();
int finalValue = Integer.parseInt(value);
new CountDownTimer(finalValue, 1000) {
public void onTick(long millisUntilFinished) {
NumberFormat f = new DecimalFormat("00");
long hour = (millisUntilFinished / 3600000) % 24;
long min = (millisUntilFinished / 60000) % 60;
long sec = (millisUntilFinished / 1000) % 60;
textView.setText(f.format(hour) + ":" + f.format(min) + ":" + f.format(sec));
}
public void onFinish() {
textView.setText("00:00:00");
}
}.start();
}
});
}
}
