Develop Reference

Passing String from Activity back to running Fragment in Android

There are a few posts about similar problems but I just don't get the wright answers and I hope that anyone can help me.
Situation:
I have a MainActivity that contains several Fragments. In one Fragment I start a CameraActivity with an intent. When the user has taken the picture, the CameraActivity gets closed with finish() and we return back to the previous Fragment.
Goal:
I give the Picture a certain name and would like to pass this name from the CameraActivity to the Fragment.
Problem:
Even though I call finish() in the CameraActivity and the screen returns back to the previous Fragment, the method onSaveInstanceState(Bundle outstate) is never called. Why is that?
Or how could I solve the problem otherwise?
Here is my code:
public class CameraActivity extends Activity {
// more code here
String imageFileName;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// some methods here
finish(); // finish the current Activity and get back to previous Fragment
}
// more code here
#Override
protected void onSaveInstanceState(Bundle outState) {
Log.d(TAG_LOG, "onSaveInstanceState() called"); // is never called!
outState.putString("imageFileName", imageFileName);
super.onSaveInstanceState(outState);
}
}
And in the Fragment I do this:
public class MapFragment extends Fragment implements View.OnClickListener {
// more code here
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_map, container, false);
// some methods here
if (savedInstanceState != null) {
String imageFileName = getArguments().getString("imageFileName");
Log.d(TAG_LOG, "image filename: " + imageFileName);
}
return view;
}
// more code here
}
Any help is highly appreciated!

You should take a look at startActivityForResults. Here is a short example (haven't tried it but you will get the idea) :
Fragment
Intent intent = new Intent(MainActivity.this,CameraActivity.class);
getActivity().startActivityForResult(intent,RESULT_PIC_TAKEN); // you may start an activity from another activity, not a fragment
CameraActivity
Intent results = new Intent();
results.putExtra("com;yourpackage.PIC_NAME", picName);
setResult(CameraActivity.RESULT_OK,results);
finish();
Back to MainActivity (since you called getActivity())
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == RESULT_PIC_TAKEN) {
if(resultCode == Activity.RESULT_OK){
Bundle results = data.getExtras();
String picName = results.getString("com.yourpackage.PIC_NAME");
// code, and send what you want to the fragment
}
}
}
Hope this will help you!

Start the CameraActivity using startActivityForResult(), once you get the string to pass back in your previous screen, just create an Intent that will contain that string, and in your MainActivity, implement:
protected void onActivityResult(int requestCode, int resultCode, Intent data)
Get the string from the intent, and pass it to your fragment.
onSaveInstanceState is used for other purposes.

How to call startactivityforresult from a non-activity class to get the resuts

Is it possible to call startActivityForResult() from a non-activity class to get the results?
Scenario is something like this:
I have a class NonActivity (it doesn't derive from Activity as its not a UI).
This class will have bunch of functions(steps basically) to run.
One of the steps requires to show UI(Activity) and then get the result (user enter something).
Then been able to use that data in next following steps.
How can this be achieved without deriving from activity class as I don't have UI component?
Also since I don't want to derive from activity class that means I cannot override OnActivityResult(). Where results actually come from?

startActivityForResult() is only available from real on-screen activities, since it is a method in, well, Activity. Please redesign your application so that the user interface is driven from activities.
On the other hand, if your non Activity class is initialized and used from an onscreen Activity, you could pass that instance of the Activity to your class as a parameter in the constructor and use it to launch other Activities.
Be careful though. Using this method increases the risk of a memory leak, as the external class (Utils in my example) might keep a reference to the Activity even after its gone.
If all you want to do is access data, then you could try writing it to SharedPreferences or a Database or some files and then using the application context (passed in via a constructor again) to read it. This reduces the risk of a memory leak. Something like:
MyApiClass myApiClass = new MyApiClass(getApplicationContext());
EXAMPLE CODE
Main Activity:
public class Main extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Utils util = new Utils(this);
util.startTest();
}
#Override
protected void onActivityResult(int arg0, int arg1, Intent arg2) {
Toast.makeText(this, "onActivityResult called", Toast.LENGTH_LONG).show();
super.onActivityResult(arg0, arg1, arg2);
}
}
Utils class (which launches for result):
public class Utils {
Activity activity;
public Utils(Activity ac) {
activity = ac;
}
public void startTest() {
Intent i = new Intent(activity, Test.class);
activity.startActivityForResult(i, 1);
}
}
Test Activity:
public class Test extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Toast.makeText(this, "Test", Toast.LENGTH_LONG).show();
this.setResult(Activity.RESULT_OK);
this.finish();
}
}

StartActivityForResult from a class using a fragment with no visible GUI. You might find something like this in a utility class.
see runGetUserAccount below. It creates its own fragment and executes a startActivityForResult. Then it has it's own onActivityResult.
public class MyGooglePlay {
private static final int CONNECTION_FAILURE_RESOLUTION_REQUEST = 31502;
private ActionBarActivity activity;
private FragmentManager fragManager;
public MyGooglePlay(ActionBarActivity activity) {
this.activity = activity;
this.fragManager = activity.getSupportFragmentManager();
}
/**
* Starts an activity in Google Play Services so the user can pick an
* account
*/
private String mEmail = "";
static final int REQUEST_CODE_PICK_ACCOUNT = 1000;
public void runGetUserAccount() {
if (TextUtils.isEmpty(mEmail)) {
// run this code in gui less fragment so we can pickup the
// on activity result from inside the mygoogleplay class.
Fragment f = new Fragment() {
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
String[] accountTypes = new String[] { "com.google" };
Intent intent = AccountPicker.newChooseAccountIntent(null,
null, accountTypes, false, null, null, null, null);
startActivityForResult(intent, REQUEST_CODE_PICK_ACCOUNT);
}
#Override
public void onActivityResult(int requestCode, int resultCode,
Intent data) {
if (requestCode == REQUEST_CODE_PICK_ACCOUNT) {
if (resultCode == Activity.RESULT_OK) {
set_Email(data
.getStringExtra(AccountManager.KEY_ACCOUNT_NAME));
// getUsername();
}
super.onActivityResult(requestCode, resultCode, data);
}
//this is to verify the fragment has been removed.
//you can log or put a breakpoint to verify
#Override public void onDestroy(){
super.onDestroy();
}
};
FragmentTransaction fragmentTransaction = this.fragManager
.beginTransaction();
fragmentTransaction.add(f, "getusername");
fragmentTransaction.commit();
}
}
/**
* #param mEmail
* the mEmail to set
*/
private void set_Email(String mEmail) {
this.mEmail = mEmail;
if (!TextUtils.isEmpty(mEmail)) {
// TODO notify caller email is ready;
// activity.onEmailReady(mEmail);
}
//we are done with the "getusername" fragment
Fragment f = fragManager.findFragmentByTag("getusername");
if (f!=null) {
fragManager.beginTransaction().remove(f).commit();
}
}
}

U should pass context as Activity,then u will get solution.
try this below code.it will work
In non Activity class
public class nonActivity {
public static void method(Activity activity)
{
Intent intent = new Intent(activity, SecondActivity.class);
activity. startActivityForResult(intent, REQUEST_CODE);
}
}
In SecondActivity
Intent intent = getIntent();
intent.putExtra("data", "data"); //here u can pass data to previous activity
setResult(RESULT_OK, intent);
finish();
In firstActivity
protected void onActivityResult(int requestCode, int resultCode, #Nullable Intent data) {
try {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_CODE && resultCode == RESULT_OK) {
String status = data.getStringExtra("data");
//Do what u want with data
}
} catch (Exception e) {
System.out.println("=====Exception=====" + e.toString());
}
}

If you want the result back from the activity to your normal class, supposed it is a class with a custom adapter within it.
you cannot use startActivityForResult because you are not in an activity
what I did is that i launched the activity from the class with an intent. Then I calculated or did what I have to. From this activity I send the information to the main class supposed with a method MainActivity.the_method() and in the main activity I changed the custom adapter o did what I have to using the adapter object and calling adapter.getItem(position)
Hope this can give you an idea

Android Override methods inside classes with Activity parameter

I want to know if I put my activity through other class like this way:
public class GateActivity extends MapActivity {
private Presenter assistant = null;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
assistant = new Presenter(this);
// ...
}
And this other class:
public class Presenter {
private android.app.Activity act;
public Presenter(android.app.Activity a){
this.act = a;
// ...
}
If it's possible in "Presenter" class to create an intent like this:
intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.INTERNAL_CONTENT_URI);
intent.setType("image/*");
act.startActivityForResult(intent, 1);
AND create/handle its "Override onActivityResult(...)" method:
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data){
switch (requestCode){
case 1: // ...
}
Thanks in advance! ;)

Yep, that should work.
When the called activity has completed, GateActivity.onActivityResult() will be called.

Clearing task and start a new activity

I don't know why this is so difficult to figure out. I have my main activity that, when launched, checks if this is the first time it's been opened. If it is, then it closes the main activity and opens the setup/introduction activity with FLAG_ACTIVITY_NEW_TASK. The setup process consists of three activities (A, B, and C). At the end of activity C, how do I get it to clear and the setup task that contains A, B, and C and start the main activity again. I've tried adding FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TOP to main activity Intent but when I press BACK, it returns to activity C of the setup process. How do I get it to clear the task of activities A, B, and C when C finishes and starts the main? Thanks!
I'm building in Android 1.6 (API 4), so some of the Activity flags may be limited.

FLAG_ACTIVITY_CLEAR_TOP will clear activities it it is of the same activity instance. Here in your case all your activities are of different instances so FLAG_ACTIVITY_CLEAR_TOP won't work. To clear your task, create an Activity instance in each of your activity and assign that instance 'this' on your onCreate method of every activity. whenever you want to clear your task jus call that instance.finish(). and start the activity that you want.

Actually this can be achieved with startActivityForResult
public class A extends Activity {
public onButtonClick() {
startActivityForResult(new Intent(this, B.class), 0);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
finish();
}
}
}
public class B extends Activity {
public onButtonClick() {
startActivityForResult(new Intent(this, C.class), 0);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
setResult(RESULT_OK);
finish();
}
}
}
public class C extends Activity {
public onButtonClick() {
setResult(RESULT_OK);
finish();
}
}
I think this is the right way, you don't leak anything this way.
PS: I know this is old post, but maybe someone will find this useful.

I answered a similar question here
As Mudassir says in their comment just finish() your activities immediately after starting a new one.

class A extends Activity {
public static Activity instanceOfA = null;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
instanceOfA = this;
}
}
class b extends Activity {
public static Activity instanceOfB = null;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
instanceOfB = this;
}
}
class c extends Activity {
public static Activity instanceOfC = null;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
instanceOfC = this;
}
}
Now suppose you want to clear all the task from your current activity, then call
instanceOfA.finish();
instanceOfB.finish();
instanceOfC.finish();

how to use startActivityForResult() in ActivityGroup?

I use a TabActivity with some tabs,each tab contain a ActvityGroup,each ActivityGroup manage more than one Activity.one of ActivtyGroups have three Activies:A,B and C.
At first A is created,when user click a button in A,it jump to B.
in B there are some important data which can be edited in C,when click a "edit"button in B,it jump to C.
if some data is edited in C,when i click back button,i want modify the same data in B.
what drive me crazy is when i use "finish()" in class C,my app exit directly.
I had searched many solutions on the net,bu none of them fit for my case,I don't know where is wrong,please help me or give me a example of how to use startActivityForResult() in ActivityGroup
here is my group:
public class MyGroup extends ActivityGroup
{
private int ID=0;
private AlertDialog dialog;
private Stack<View>history;
private LocalActivityManager manager;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
history = new Stack<View>();
manager = getLocalActivityManager();
Intent intent = new Intent(this,A.class);
startActivity(intent);
}
#Override
public void startActivity(Intent intent)
{
View view = manager.startActivity(""+ID++,intent).getDecorView();
history.push(view);
setContentView(view);
}
#Override
public void startActivityForResult(Intent intent,int requestCode)
{
// super.startActivityForResult(intent, requestCode);
View view = manager.startActivity(""+ID++,intent).getDecorView();
history.push(view);
setContentView(view);
}
/*
* if user edited data in C.class.
* when C.class finished,refresh data in the B.class
*/
#Override
protected void onActivityResult(int requestCode,int resultCode,Intent data)
{
Log.e("MyGroup","running");
super.onActivityResult(requestCode, resultCode, data);
if(resultCode==RESULT_OK)
{
//modify data in B.java
B subActivity=(B)(manager.getCurrentActivity());
subActivity.handleActivityResult(requestCode, resultCode, data);
}
}
/*
* when press back button, manage which page to show next
* if there is one page in stack,that means when press back button it will
* exit the app,so we add a dialog to notify user whether exit app or not
*/
#Override
public void onBackPressed()
{
int size=history.size();
if ( history.size()>= 2)
{
history.remove(size-1);
setContentView(history.get(size-2));
}
else
{
if(dialog==null)
{
createDialog();
}
dialog.show();
}
}
}
in B.class:
public void nextPage()
{
Intent intent=new Intent(B.this,C.class);
intent.putExtra("name", productAdapter.getName(position));
intent.putExtra("id", productAdapter.getID(position));
B.this.getParent().startActivityForResult(intent,11);
}
/*
* modify data in modifyItem
*/
public void handleActivityResult(int requestCode,int resultCode,Intent data)
{
String price=data.getExtras().getString("price");
String name=data.getExtras().getString("name");
String quantity=data.getExtras().getString("quantity");
productAdapter.setName(name, modifyItem);
productAdapter.setPrice(price, modifyItem);
productAdapter.setQuantity(quantity, modifyItem);
productAdapter.notifyDataSetChanged();
}
in C.class:
#Override
public void onBackPressed()
{
if(price!=null)
{
Bundle bundle=new Bundle();
bundle.putString("name",name);
bundle.putString("price",price);
bundle.putString("quantity",quantity);
this.getParent().setResult(RESULT_OK,new Intent().putExtras(bundle));
this.finish();
Log.e("C","inner");
}
Log.e("C","outer");
this.getParent().onBackPressed();
}

Why do you call finish? Pressing back means it will destroy

Your Activity from a ActivityGroup will not get the response calls directly.
You need to redirect from ActivityGroup.
Please see the below answer
Here is the solution. Please try this
https://stackoverflow.com/a/15047518/1403112