In my app I get the current time and convert it to a string.
as you see this string will be changed every time I open the activity But I want to save this time string in a static string which if I went back to this activity I could show it to user.
This is my code so far:
Time now = new Time();
now.setToNow();
String str = now.toString().substring(0, 15);
textview.setText(str);
Actually I have a listview that has items.
this time string is in listview.onitemclicklistener and I want to whenever that item is created I save the time and when users clicked on that I show that time in second activity.
For example if user created the item in listview in two days ago, when clicks on that Item I show two days ago date and time:
This my code with more details:
first activity:
list.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
Time now = new Time();
now.setToNow();
String timedate = now.toString().substring(0, 15);
Intent intent = new Intent(Albums.this, AlbumPage.class);
intent.putExtra("extra", timedate);
startActivity(intent);
}
second activity:
String str = getIntent().getExtras().getString("extra");
textview.setText(str);
in this way when I click on each Item it just shows the current time not the time that Item is created (my listview is dynamic an user can add or delete items).
Try below code:
SharedPreferences sharedpreferences = getSharedPreferences("myPrefs",
Context.MODE_PRIVATE);
Editor editor = pref.edit();
Time now = new Time();
now.setToNow();
String str = now.toString().substring(0, 15);
editor.putString("key_name", str);
editor.commit();
textview.setText(str);
use this code in your Activity's onPause or onDestroy
SharedPreferences sharedpreferences = getSharedPreferences("PREF",
Context.MODE_PRIVATE);
Editor editor = sharedpreferences.edit();
Time now = new Time();
now.setToNow();
String str = now.toString().substring(0, 15);
editor.putString("time", str);
editor.commit();
then to Retrieve it use the following code in onStart() method
SharedPreferences sharedpreferences = getSharedPreferences("PREF",
Context.MODE_PRIVATE);
String time = sharedpreferences.getString("time" "default_value");
Add below code where you want to save current time.
list.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
//declare pref editor
SharedPreferences prefs;
SharedPreferences.Editor prefsEditor;
prefs = PreferenceManager.getDefaultSharedPreferences(this);
String savedTime=prefs.getString("time", "");
//now check the value of shared pref and apply the condition like this
if(savedTime.isEmpty()) {
//set time if time is not set
prefsEditor = prefs.edit();
Time now = new Time();
now.setToNow();
String str = now.toString().substring(0, 15);
prefsEditor.putString("time", str);
prefsEditor.commit();
Intent intent=new Intent(this, class2.class);
startActivity(intent);
}
else {
//perform your action here if time is already set
Intent intent=new Intent(this, class2.class);
startActivity(intent);
}
}
Related
i have successfully implemented a calculator with a history activity in which it will show old results in a list view
but i am facing a problem that the first line is always null
https://imgur.com/a/jvXms
i tried to make default string " Old Calculation "
> String w = "Old Calculation";
but this didn't work,
my app save the result in a multiline String in SharedPreferences and pass it to another activity through an intent
>SharedPreferences.Editor editor ; // saving shared preferences editor as MainAcitivty class attribute
under the onCreate i set the String value to sharedpref
> SharedPreferences prefs = getPreferences(MODE_PRIVATE);
w = prefs.getString("saved", null);
update method in which i update the result string value with the String s( String s is the calculated result)
> public void update(String s){
editor= getPreferences(MODE_PRIVATE).edit();
w = w
+ System.getProperty ("line.separator")
+ s
+ System.getProperty ("line.separator");
editor.putString("saved", w);
editor.apply();
}
Passing W value to the activity in which i will show the result in TextView list
> public void History(View v){
Intent myIntent = new Intent(MainActivity.this, History.class);
myIntent.putExtra("message", w);
startActivity(myIntent);
overridePendingTransition(R.anim.anim_slide_in_left,
R.anim.anim_slide_out_left);
}
History activity
public class History extends AppCompatActivity {
TextView tv1;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_history);
String w ="Old calculation is showed here";
tv1 = (TextView) findViewById(R.id.tv1);
print(w);
}
public void print(String w) {
Bundle bundle = getIntent().getExtras();
w = bundle.getString("message");
tv1.setMovementMethod(new ScrollingMovementMethod());
tv1.setText(w);
}
#Override
public void onBackPressed() {
super.onBackPressed();
overridePendingTransition(R.anim.anim_slide_in_right, R.anim.anim_slide_out_right);
}
public void deleteAppData(View v) {
try {
// clearing app data
String packageName = getApplicationContext().getPackageName();
Runtime runtime = Runtime.getRuntime();
runtime.exec("pm clear "+packageName);
} catch (Exception e) {
e.printStackTrace();
}
}
}
when you store data from activity A and you want retrieve it from another activity, You must use SharedPreferences as below:
SharedPreferences prefs = getSharedPreferences(String, int);
String is FileName like "result"
int is Mode like MODE_PRIVATE
for example see this link
in addition i wrote a simple code for help you
I am using shared preferences but my code is not working. I don't know what's wrong with it. Am I implementing something wrong?
My main java activity(relevant bit of code) is:
public class MainActivity extends AppCompatActivity {
private String s;
public static final String subjectKey = "SubjectID";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final SharedPreferences sharedPreferences = getSharedPreferences(subjectKey, Context.MODE_PRIVATE);
TextView calc_monday = (TextView) findViewById(R.id.monday_calc);
calc_monday.setOnClickListener(
new Button.OnClickListener(){
public void onClick(View v){
CustomDialogClass cdd = new CustomDialogClass(MainActivity.this);
cdd.show();
TextView text1 = (TextView) cdd.findViewById(R.id.Subject_ID);
String text = sharedPreferences.getString(subjectKey, " ");
if(text != " ")
{
text1.setText(text); /* Edit the value here*/
}
TextView text2 = (TextView) cdd.findViewById(R.id.Room_ID);
text2.setText("6 (SEECS)");
TextView text3 = (TextView) cdd.findViewById(R.id.Time_ID);
text3.setText("09:00am - 09:50am");
}
}
);
calc_monday.setOnLongClickListener(
new Button.OnLongClickListener() {
public boolean onLongClick(View v) {
SettingDialogClass SDC = new SettingDialogClass(MainActivity.this);
SDC.show();
EditText texii = (EditText) SDC.findViewById(R.id.set_Subject_ID);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(subjectKey, texii.getText().toString());
editor.apply();
return true;
}
}
);
Basically I want that when I longClick a textbox (calc_monday), a dialog box should appear which appears. Now I should be able to write something on the EditText field which appears on this dialog box. Whatever I write should be stored and then displayed when I SINGLE CLICK on the same textbox (calc_monday)
Please see the 2 methods: onClick and onLongClick to understand.
The code is not working, i.e the text I write on EditText field on onLongCLick dialog box is not being displayed when I single click on the textbox.
What's wrong with the code
When you long press calc_monday, it just show your custom dialog with empty value for EditText. To save your text when input in EditText, create a button in your custom dialog, and call onClickListener action for this button, then save value to SharePreferences.
calc_monday.setOnLongClickListener(
new Button.OnLongClickListener() {
public boolean onLongClick(View v) {
SettingDialogClass SDC = new SettingDialogClass(MainActivity.this);
EditText texii = (EditText) SDC.findViewById(R.id.set_Subject_ID);
Button btnSave = (Button)SDC.findViewById(R.id.your_custom_button);
btnSave.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(subjectKey, texii.getText().toString());
editor.apply();
SDC.dismiss();
}
});
SDC.show();
return true;
}
}
);
I think it's should be :
String text = sharedPreferences.getString("Name", " ");
Try these methods for saving and loading Strings with preferences:
//save prefs
public void savePrefs(String key, String value){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(key, value);
editor.commit();
}
//get prefs
public String loadPrefs(String key, String value){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
String data = sharedPreferences.getString(key, value);
return data;
}
You can call the load method like this:
subjectKey = loadPrefs("YouCanNameThisAnything", subjectKey);
And you can call the save method like this:
savePrefs("YouCanNameThisAnything", subjectKey);
More details on how to use shared preferences is also available in the documentation here:
http://developer.android.com/reference/android/content/SharedPreferences.html
//create and initialize the intance of shared preference
SharedPreferences sharedPreferences = getSharedPreferences("Session", MODE_PRIVATE);
//save a string
SharedPreferences.Editor edit = sharedPreferences.edit();
edit.putString(subjectKey , texii.getText().toString());
edit.commit();
//retrieve the string
String subject = sharedPreferences.getString(subjectKey, "");
In my MainActivity I have a textView.
In that textView there is a Number that I keep in a SharedPreferences.
and every couple of min The SharedPreferences is changed with an alarm manager,
but the SharedPreferences in my MainActivity wont change,
anyone has an idea why?
this is a part of The code in the MainActivity
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
int ReleaseDate = preferences.getInt("com.fisher.freedom.ReleaseDate", 0);
TextView edit = (TextView) findViewById(R.id.DaysLeft);
Toast.makeText(MainActivity.this, "" + preferences.getInt("com.fisher.freedom.ReleaseDate", 0), Toast.LENGTH_SHORT).show();
edit.setText("" + ReleaseDate);
This is the code in the AlarmReceiver
public static final String ReleaseDate_Key = "com.fisher.freedom.ReleaseDate";
#Override
public void onReceive(Context context, Intent intent) {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
int ReleaseDate = preferences.getInt(ReleaseDate_Key, 0);
SharedPreferences.Editor editor = preferences.edit();
editor.putInt(ReleaseDate_Key, --ReleaseDate);
editor.apply();
For get the value of your int use this:
SharedPreferences sharedPreferences = getSharedPreferences(getApplicationContext().getPackageName(),0);
int ReleaseDate = sharedPreferences.getInt("ReleaseDate",0);
And to save it use this:
SharedPreferences prefs = getSharedPreferences(getApplicationContext().getPackageName(), Context.MODE_PRIVATE);
prefs.edit().putInt("ReleaseDate", ReleaseDate).commit();
With this you forget about writing on static variable your package name, it worked for me, so it's going for you.
As we know to save something like int value's we use this
SharedPreferences pref = getSharedPreferences("SavedGame", MODE_PRIVATE);
SharedPreferences.Editor editor = pref.edit();
editor.putInt("Something", "Value");
editor.commit();
}
now my question how to save something like chronometer time with sharedpreferences? as we know chronometer code like this
focus = (Chronometer) findViewById(R.id.chronometer1);
focus.setOnChronometerTickListener(new OnChronometerTickListener(){
#Override
public void onChronometerTick(Chronometer cArg) {
long time = SystemClock.elapsedRealtime() - cArg.getBase();
int h = (int)(time /3600000);
int m = (int)(time - h*3600000)/60000;
int s= (int)(time - h*3600000- m*60000)/1000 ;
String hh = h < 10 ? "0"+h: h+"";
String mm = m < 10 ? "0"+m: m+"";
String ss = s < 10 ? "0"+s: s+"";
cArg.setText(hh+":"+mm+":"+ss);
}
});
to start the chronometer, put this in a button called "Button Start"
focus.setBase(SystemClock.elapsedRealtime());
focus.start();
to stop the chronometer, put this in a button called "Button Stop"
focus.stop();
Ok, so my question is how to save the chronometer time/tick if "Button Stop" was pressed? Thank's
Using your terminology, you have to put this piece of code:
SharedPreferences pref = getSharedPreferences("SavedGame", MODE_PRIVATE);
SharedPreferences.Editor editor = pref.edit();
editor.putInt("Something", "Value");
editor.commit();
into your 'Button Stop' OnClickListener
stopButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
//here
}
});
I have a configuration page which has a form on it. When the button is pressed, I want to save that value to a SharedPreference. This SharedPreference value then needs to be accessed from elsewhere in my app.
I am trying to save the value like the below. I want to save the collectionID so I can use it elsewhere
public class ConfigPage extends Activity {
public static final String PREFS_NAME = "MyPrefsFile";
Button mButton;
EditText mEdit;
String collectionID;
String key = "GregKey";
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.config);
getActionBar().hide();
mButton = (Button)findViewById(R.id.setCollection);
mEdit = (EditText)findViewById(R.id.collectionName);
mButton.setOnClickListener(
new View.OnClickListener()
{
public void onClick(View view)
{
collectionID = mEdit.getText().toString();
Log.d("EditText", collectionID);
SharedPreferences settings =
getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(key, collectionID);
editor.commit();
}
});
}
}
Once it has been saved, I then need to access it in another class, however I can't figure out how to do this. The example above crashes the application at the moment so something isn't quite right
I want to save the collectionID so I can use it elsewhere
Use mButton Button onClick event for saving EditText text in SharedPreferences as :
mButton.setOnClickListener( new View.OnClickListener()
{
public void onClick(View view)
{
collectionID = mEdit.getText().toString();
Log.d("EditText", collectionID);
// save value here in SharedPreferences
SharedPreferences settings =
ConfigPage.this.getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(collectionID, collectionID);
editor.commit();
}
});
Your crash occurs because your value is null:
String savedID;
You need to add a value to the variable:
String savedID = "somevalue";
Also, your key is null as long as the Button is not pressed which will also lead to a crash.
The putString(String key, String value) method enables you to store a specific value with a specific key, that can later be used to reaccess the stored value.
Example:
String key = "somekey";
String value = "yourvaluetostore";
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(key, value); // store the value
editor.commit();
In another Activity:
String key = "somekey";
SharedPreferences sharedPreferences = getSharedPreferences(PREFS_NAME, 0);
// get the value "" is default
String value = sharedPreferences.getString(key, "");
All you need in the other Activity is the key you stored the value with. With this key, you can pull the correct stored value out of the SharedPreferences. --> The key is needed to identify the value.
Since you are using the part of code :
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(collectionID, savedID);
editor.commit();
Log.d("Saved as", savedID);
in the onCreate method, that translates to
...
editor.putString(null, null);
Log.d("Saved as", null);
Correct your code so that you fill those elements before. I guess you wanted to make the save in the OnClick part
Yes something its not quite right here because as i see you are saving nothing. on shared pref you should have a "key" which will be use to identify the saved value in your example it should be something like this
public class ConfigPage extends Activity {
public static final String PREFS_NAME = "MyPrefsFile";
public static final String COLLECTIONID_KEY = "COLLECTIONID_KEY";
Button mButton;
EditText mEdit;
String collectionID;
String savedID;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.config);
getActionBar().hide();
mButton = (Button)findViewById(R.id.setCollection);
mEdit = (EditText)findViewById(R.id.collectionName);
mButton.setOnClickListener(
new View.OnClickListener()
{
public void onClick(View view)
{
collectionID = mEdit.getText().toString();
Log.d("EditText", collectionID);
}
});
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString(COLLECTIONID_KEY, collectionID);
editor.commit();
Log.d("Saved as", COLLECTIONID_KEY);
}
}
then to retrieve it :
SharedPreferences sharedPreferences = getSharedPreferences(PREFS_NAME, 0);
String mySavedCollectionID = sharedPreferences.getString(COLLECTIONID_KEY);
and make sure that its done on the Onclick event otherwise you might end up with crash again because after the on-click event in your code the lines below will run anyway and save null!