Hi my MainActivity and MainActivity2 are supposed to be saving the instance state, but when I rotate the device into landscape it does not save the time, the timer restarts. My app is a log in verication that displays time stamps when you click the verify button, right now I am trying to save the timer when I rotate the device, but it is not saving I will include the code below thanks.
package com.example.security_token_app;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.os.PersistableBundle;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Locale;
import java.util.Calendar;
public class MainActivity extends AppCompatActivity
{
private static String SHARED_PREF_NAME = "SharedPrefFile";
SharedPreferences sharedPreferences;
SharedPreferences.Editor editor;
private static String TIMESTAMP_KEY = "TIMESTAMP_KEY";
private TextView countDownTextView;
TextView passCodeTextView;
static int passCode;
static String currentDateTime;
static ArrayList<String> arrayIntegerList = new ArrayList<String>();
Button verifyButton;
private static String LOG_TAG = "log state 1";
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
countDownTextView = (TextView)findViewById(R.id.textView4_time_remaining);
passCodeTextView= (TextView)findViewById(R.id.textView3_passCode_int);
verifyButton = (Button)findViewById(R.id.button1);
sharedPreferences = getSharedPreferences(SHARED_PREF_NAME,MODE_PRIVATE);
createPassCode();
new CountDownTimer(60000, 1000)
{
@Override
public void onTick(long timeUntillFinished)
{
countDownTextView.setText("seconds remaining: " timeUntillFinished / 1000 % 60);
}
@Override
public void onFinish()
{
createPassCode();
start();
}
}.start();
verifyButton.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)
{
String check = sharedPreferences.getString(TIMESTAMP_KEY, null);
Log.i("k1","timestamp: " check);
if(check != null)
{
arrayIntegerList.add(check);
Toast.makeText(getBaseContext(), "restored", Toast.LENGTH_SHORT).show();
}
openSecondaryActivity();
}
});
}
public void createPassCode()
{
int minute = Calendar.getInstance().get(Calendar.MINUTE);
passCode=minute*1245 10000;
String timeStamp = getTimeStamp();
arrayIntegerList.add(timeStamp);
String passCodeStr = Integer.toString(passCode);
passCodeTextView.setText(passCodeStr);
}
public void openSecondaryActivity()
{
Intent intent = new Intent(this, MainActivity2.class);
intent.putExtra("timestamp_list", arrayIntegerList);
startActivity(intent);
}
public static int getPassCode()
{
return passCode;
}
public static String getTimeStamp()
{
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
currentDateTime = dateFormat.format(new Date());
return currentDateTime;
}
@Override
public void onSaveInstanceState(@NonNull Bundle outState, @NonNull PersistableBundle outPersistentState)
{
super.onSaveInstanceState(outState, outPersistentState);
Log.i(LOG_TAG, "saved state success");
TextView textView = (TextView) findViewById(R.id.textView4_time_remaining);
CharSequence savedData = textView.getText();
outState.putCharSequence("outStateKey", savedData);
}
@Override
public void onRestoreInstanceState(@Nullable Bundle savedInstanceState, @Nullable PersistableBundle persistentState)
{
super.onRestoreInstanceState(savedInstanceState, persistentState);
Log.i(LOG_TAG, "restore state success");
CharSequence storedData = savedInstanceState.getCharSequence("outStateKey");
TextView textView = (TextView)findViewById(R.id.textView4_time_remaining);
textView.setText(storedData);
}
}
package com.example.security_token_app;
import androidx.appcompat.app.AppCompatActivity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
public class MainActivity2 extends AppCompatActivity
{
SharedPreferences sharedPreferences;
private static String SHARED_PREF_NAME = "SharedPrefFile";
private static String TIMESTAMP_KEY = "TIMESTAMP_KEY";
ArrayList<String> arrayList = new ArrayList<String>();
ListView listView;
Button clearButton;
int count;
String item;
static ArrayAdapter<String> adapter;
static boolean isSaved = false;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
listView = (ListView) findViewById(R.id.listView1);
clearButton = (Button) findViewById(R.id.passButton);
sharedPreferences = getSharedPreferences(SHARED_PREF_NAME,MODE_PRIVATE);
ArrayList<String> timestampList = (ArrayList<String>)getIntent().getSerializableExtra("timestamp_list");
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, timestampList);
listView.setAdapter(adapter);
clearButton.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)
{
count = adapter.getCount();
String checkFirstPass = sharedPreferences.getString(TIMESTAMP_KEY,null);
Log.i("k2","timestamp: " checkFirstPass);
if(checkFirstPass==null)
{
item = adapter.getItem(count - 1);
}
else if(checkFirstPass!=null)
{
item = adapter.getItem(count-2);
}
adapter.clear();
adapter.add(item);
saveTimeStamp(item);
}
});
}
public void saveTimeStamp(String lastItem)
{
if(!lastItem.isEmpty())
{
sharedPreferences = getSharedPreferences(SHARED_PREF_NAME,MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(TIMESTAMP_KEY, lastItem);
editor.apply();
Toast.makeText(getBaseContext(), "time stamp saved", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(getBaseContext(), "nothing saved", Toast.LENGTH_SHORT).show();
}
}
}
<?xml version="1.0" encoding="utf-8"?>
<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:id="@ id/root_constraint_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<LinearLayout
android:id="@ id/linear_layout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:layout="@layout/activity_main">
<TextView
android:id="@ id/textView1_blueBox"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_gravity="center"
android:layout_weight="0.25"
android:background="@color/sky_blue"
android:text="test" />
<TextView
android:id="@ id/textView2_passCode_string"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.5"
android:textAlignment="center"
android:text="PASS CODE"
android:textStyle="bold"
android:textSize="38sp"/>
<TextView
android:id="@ id/textView3_passCode_int"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.5"
android:textAlignment="center"
android:textSize="38sp"
android:textStyle="bold"
android:text="test" />
<TextView
android:id="@ id/textView4_time_remaining"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.5"
android:textAlignment="center"
android:textSize="24sp"
tools:text="1:00 seconds remaining"/>
<Button
android:id="@ id/button1"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="center"
android:text="Verify"
android:textStyle="bold"
/>
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
<?xml version="1.0" encoding="utf-8"?>
<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=".MainActivity2">
<LinearLayout
android:id="@ id/linear_layout1"
android:layout_width ="match_parent"
android:layout_height ="match_parent"
android:orientation="vertical"
tools:layout="@layout/activity_main">
<TextView
android:id="@ id/textView1_blueBox"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_gravity="center"
android:layout_weight="0.25"
android:background="@color/sky_blue" />
<ListView
android:id="@ id/listView1"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:textStyle="bold"
android:dividerHeight="32dp"
/>
<Button
android:id="@ id/passButton"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="center"
android:text="PASS"
android:textStyle="bold"
/>
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
CodePudding user response：
ViewModel Use ViewModelenter link description here
It's no problem to rotate
You can learn about the login module of Android studio enter image description here
CodePudding user response：
Use ViewModel to solve this problem
if you need a practical implementation of how to use this here