Develop Reference

How to return data from a fragment using androidx.navigation?

I open a selection fragment using androidx.navigation, but I cannot find a way to return data to the previous fragment.

In one parent activity.. just use global variable that able to access inside same parent activity or
Other trick you can try preference, so that preference will able to read anywhere you want.
Data share active fragment
sharedPref = context.getSharedPreferences(context.getPackageName(),MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPref.edit();
prefEditor.putString(sKey, sValue);
prefEditor.apply();
Data read from other fragment
sharedPref = context.getSharedPreferences(context.getPackageName(),MODE_PRIVATE);
sValue = sharedPref.getString(sKey,defValue);

how to make check box check on button click in different activity in android

in my android app there is terms and condition fragment and in that there are two buttons accept and decline, the scenario is when user click on terms and condition the fragment open and user have two options accept and declined and when he press the accept button it return to main activity and there is one checkbox that should be check when user click on accept button in the fragment,So can anyone tell me how should i do that?

By using SharedPreferences short quick example:
SharedPreferences pref = getApplicationContext().getSharedPreferences("MyPref", 0);
Editor editor = pref.edit();
editor.putBoolean("switchOn", true);
editor.commit();
on the second activity
SharedPreferences pref = getApplicationContext().getSharedPreferences("MyPref", 0);
Editor editor = pref.edit();
boolean buttonOn = editor.getBoolean("switchOn", false);

How to call strings in fragment from activity?

I have Activity A that has String that updates every 1s.
I also have Fragment B which has a Button and a TextView.
When I press my button in Fragment B I want to get String from Activity A to my TextView.
How do I do this?

SharedPreferences.Editor editor = getSharedPreferences(YOUR_PREFS_NAME, MODE_PRIVATE).edit();
editor.putString("DATA_NAME", "YOUR_DATA");
editor.commit();
On the Button Click
SharedPreferences prefs = getSharedPreferences(YOUR_PREFS_NAME, MODE_PRIVATE);
String restoredData = prefs.getString("DATA_NAME", DEFAULT);
yourTextView.setText(restoredData );

How to link a favorite button to a new activity?

I want to add a favorite button in a layout which can save the layout and apply it to another activity. I'll show you an image bellow to understand exactly the way I want to do it..
I created the favorite button, and the activity for this button to save the layout, but the app is still crashing when I press the favorite button and the activity which should open the layout, which I have saved, is blank. Here are the code:
public void onClick(View v){
SharedPreferences prefs = this.getSharedPreferences(
getApplicationContext().getPackageName(), Context.MODE_PRIVATE);
prefs.edit().putString("activity", "YourActivityName");
}
public void onClick(View v){
SharedPreferences prefs = this.getSharedPreferences(
getApplicationContext().getPackageName(), Context.MODE_PRIVATE);
String activityToRun = prefs.getString("activity", "noFavorites");
if(activityToRun.equals("noFavorites")
return null;
if(activityToRun.equals("YOUR FIRST ACTIVTY")
//code for launching activity
}
I added this to Favorite.java, and I created another activity, called Favorite2.java which should be open the layout saved by the favorite button, but what I don't understand is how I can link the saved layout to the activity Favorite2.java?
And please, if someone can tell me exactly the explanation for getString and putString and the way that they should be implemented.

How to call another intent without losing previous data?

I have 2 pages in my application. From Page A I am calling Page B. On page B I have a ListView which is filled by users. Now when User clicks on Back Button of the phone he comes back to Page A. But when he clicks menu and select Add Items again, it opens Page B but my ListView is empty. How can I get back to Page B without losing data in ListView?

Override the onBackPressed in page B, and save your data some where..
then in the onStart of page B reload the data..

One way to accomplish this is to use the SharedPreferences:
public void onStop(Bundle bundle)
{
SharedPreferences mySharedPreferences = getPreferences(MODE_PRIVATE);
SharedPreferences.Editor editor = mySharedPreferences.edit();
editor.putBoolean("myBool",true);
//Continue saving all the data you need to recreate the listView
}
Then when you restart the activity, you can reload the preferences in the OnCreate() method like this:
public void onCreate(Bundle bundle)
{
SharedPreferences mySharedPreferences = getPreferences(MODE_PRIVATE);
// Retrieve the saved values.
boolean myBool = mySharedPreferences.getBoolean("myBool");
//Recreate the ListView here
}
It might not be the cleanest way to do so. But since onSavedInstanceState can't be used in your case, it will have to do :)

You can use SharedPreferences to save and load the data in a list
I.e
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
SharedPreferences settingsActivity = getPreferences(MODE_PRIVATE);
SharedPreferences.Editor prefEditor = settingsActivity.edit();
prefEditor.putString(LISTFROMB, savedItems);
prefEditor.commit();
}
return super.onKeyDown(keyCode, event);
}
And then load it in A like :
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.simple);
// Find the ListView resource.
mainListView = (ListView) findViewById(R.id.list);
ArrayList<String> selectedItems = new ArrayList<String>();
SharedPreferences settingsActivity = getPreferences(MODE_PRIVATE);
String savedItems = settingsActivity.getString(LISTFROMB, "");
selectedItems.addAll(Arrays.asList(savedItems.split(",")));
[CALL YOUR ADAPTER HERE WITH THE SELECTED ITEMS LIST]
}

Thanks for your help. I solved the problem just by declaring the ArrayList in Page A. So now when I go back to Page B the source of the ListView is in Page A so easy to load it back.
Don't know if this approach is wrong. Please leave your comment if you think this shouldn't be done.