how to handle a getIntent() method with java nullpointerexception - java

I have 2 activities in my application, Activity1 and Activity2.When the app launches Acitivity1 is the the one that is called.Clicking on a button in Activity1 should take you to Activity2.
In Acivity2,some data processing is done then i send back data to Activity1 using an intent like this:
Intent in=new Intent(getApplicationContext(), Activity1.class);
in.putExtra("data", data);
startActivity(in);
Then getting back to Activity1 i obtain the intent data:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity1);
String data =(getIntent().getExtras().getString("data"));
The problem here is that the first time the app launches it checks for the intent data and it does not exist so i get the nullpointerexception error.how can i make sure it checks for the intent data when Activity2 is the previous class?

You can check if the intent is existing using:
getIntent().hasExtra("data");
This will return you a boolean.
Also if oyu want to return some datas to the first activity, your should start the second one with startActivityForResult

if (extras != null) {
if (extras.containsKey("data")) {
boolean hasData = extras.getBoolean("data", false);
// TODO: Do something with the value of "data".
}
}

put a check over it
if(getIntent().getExtras()!=null){
String data =(getIntent().getExtras().getString("data"));
}

Follow the following steps
1: from your activity1's button click call as follow
Intent i = new Intent(this, SecondActivity.class);
startActivityForResult(i, 1);
2: In your Activity2 set the data which you want to return back to Activity1 as follow and if you don't want to return back don't set anything.
Intent returnIntent = new Intent();
returnIntent.putExtra("result",result);
setResult(RESULT_OK,returnIntent);
finish();
if you don't want to return data:
Intent returnIntent = new Intent();
setResult(RESULT_CANCELED, returnIntent);
finish();
3: now again in your Activity1 handle the return data as follow
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1) {
if(resultCode == RESULT_OK){
String result=data.getStringExtra("result");
}
if (resultCode == RESULT_CANCELED) {
//Write your code if there's no result
}
}
}
EDIT:
and if you strictly want to use your own method as in your question try this:
in your Activity1 you obtain the intent data as:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity1);
String data ="default value";
try{
data =(getIntent().getExtras().getString("data"));
}catch(Exception e){
}
}

use ActvityForResult.
replace these codes.
in ACTVITY1:
put this after onCreate:
#Override
protected void onActivityResult(int requestCode ,int resultCode ,Intent data ) {
super.onActivityResult(requestCode, resultCode, data);
String name =data.getStringExtra("data");
if(resultCode == RESULT_OK){
switch(requestCode){
case 2:
if(resultCode == RESULT_OK){
Toast.makeText(this, name, Toast.LENGTH_LONG).show();
}
}
}
in ACTIVITY2:
Intent intent=new Intent();
intent.putExtra("data",data);
setResult(2,intent);
finish();

Related

Refresh Activity

This is my scenario
Activity A (List of user)
Activity B (User Add Activity)
Desired Flow in app
Step 1: A ==> B
Step 2: B ==> A
Step 3 (Required flow):
Activity A has to reload itself or call loadListView() function after Activity B exits or is closed.
onCreate(){
.......
....
btnAddClient.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent( ActivityA.this, ActivityB.class);
startActivity(intent);
}
});
loadListView();
......
....
}
Try to call loadListView() in onStart or onResume methods. It will refresh the list when you come back to your activity
Getting a result from an activity
From your Activity A, call the Activity B using the startActivityForResult() method.
int RESULT_CODE = 123;
Intent intent = new Intent(this, ActivityB.class);
startActivityForResult(intent, RESULT_CODE);
Now in your ActivityA class, write the following code for the onActivityResult() method.
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == RESULT_CODE) {
if(resultCode == Activity.RESULT_OK){
bool status=data.getBooleanExtra("isUserAdded");
if(status)
{
loadListView();
}
}
}
} //onActivityResult
Return back to ActivityA with status.
Intent returnIntent = new Intent();
returnIntent.putExtra("isUserAdded",true);
setResult(Activity.RESULT_OK,returnIntent);
finish();

How to pass a callback method between Xamarin Android activites [duplicate]

In my activity, I'm calling a second activity from the main activity by startActivityForResult. In my second activity, there are some methods that finish this activity (maybe without a result), however, just one of them returns a result.
For example, from the main activity, I call a second one. In this activity, I'm checking some features of a handset, such as does it have a camera. If it doesn't have then I'll close this activity. Also, during the preparation of MediaRecorder or MediaPlayer if a problem happens then I'll close this activity.
If its device has a camera and recording is done completely, then after recording a video if a user clicks on the done button then I'll send the result (address of the recorded video) back to the main activity.
How do I check the result from the main activity?
From your FirstActivity, call the SecondActivity using the startActivityForResult() method.
For example:
int LAUNCH_SECOND_ACTIVITY = 1
Intent i = new Intent(this, SecondActivity.class);
startActivityForResult(i, LAUNCH_SECOND_ACTIVITY);
In your SecondActivity, set the data which you want to return back to FirstActivity. If you don't want to return back, don't set any.
For example: In SecondActivity if you want to send back data:
Intent returnIntent = new Intent();
returnIntent.putExtra("result",result);
setResult(Activity.RESULT_OK,returnIntent);
finish();
If you don't want to return data:
Intent returnIntent = new Intent();
setResult(Activity.RESULT_CANCELED, returnIntent);
finish();
Now in your FirstActivity class, write the following code for the onActivityResult() method.
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == LAUNCH_SECOND_ACTIVITY) {
if(resultCode == Activity.RESULT_OK){
String result=data.getStringExtra("result");
}
if (resultCode == Activity.RESULT_CANCELED) {
// Write your code if there's no result
}
}
} //onActivityResult
To implement passing data between two activities in a much better way in Kotlin, please go through 'A better way to pass data between Activities'.
How to check the result from the main activity?
You need to override Activity.onActivityResult() and then check its parameters:
requestCode identifies which app returned these results. This is defined by you when you call startActivityForResult().
resultCode informs you whether this app succeeded, failed, or something different
data holds any information returned by this app. This may be null.
Example
To see the entire process in context, here is a supplemental answer. See my fuller answer for more explanation.
MainActivity.java
public class MainActivity extends AppCompatActivity {
// Add a different request code for every activity you are starting from here
private static final int SECOND_ACTIVITY_REQUEST_CODE = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
// "Go to Second Activity" button click
public void onButtonClick(View view) {
// Start the SecondActivity
Intent intent = new Intent(this, SecondActivity.class);
startActivityForResult(intent, SECOND_ACTIVITY_REQUEST_CODE);
}
// This method is called when the second activity finishes
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// check that it is the SecondActivity with an OK result
if (requestCode == SECOND_ACTIVITY_REQUEST_CODE) {
if (resultCode == RESULT_OK) { // Activity.RESULT_OK
// get String data from Intent
String returnString = data.getStringExtra("keyName");
// set text view with string
TextView textView = (TextView) findViewById(R.id.textView);
textView.setText(returnString);
}
}
}
}
SecondActivity.java
public class SecondActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
}
// "Send text back" button click
public void onButtonClick(View view) {
// get the text from the EditText
EditText editText = (EditText) findViewById(R.id.editText);
String stringToPassBack = editText.getText().toString();
// put the String to pass back into an Intent and close this activity
Intent intent = new Intent();
intent.putExtra("keyName", stringToPassBack);
setResult(RESULT_OK, intent);
finish();
}
}
Complementing the answer from Nishant, the best way to return the activity result is:
Intent returnIntent = getIntent();
returnIntent.putExtra("result",result);
setResult(RESULT_OK,returnIntent);
finish();
I was having a problem with
new Intent();
Then I found out that the correct way is using
getIntent();
to get the current intent.
startActivityForResult: Deprecated in Android X
For the new way we have registerForActivityResult.
In Java :
// You need to create a launcher variable inside onAttach or onCreate or global, i.e, before the activity is displayed
ActivityResultLauncher<Intent> launchSomeActivity = registerForActivityResult(
new ActivityResultContracts.StartActivityForResult(),
new ActivityResultCallback<ActivityResult>() {
#Override
public void onActivityResult(ActivityResult result) {
if (result.getResultCode() == Activity.RESULT_OK) {
Intent data = result.getData();
// your operation....
}
}
});
public void openYourActivity() {
Intent intent = new Intent(this, SomeActivity.class);
launchSomeActivity.launch(intent);
}
In Kotlin :
var resultLauncher = registerForActivityResult(StartActivityForResult()) { result ->
if (result.resultCode == Activity.RESULT_OK) {
val data: Intent? = result.data
// your operation...
}
}
fun openYourActivity() {
val intent = Intent(this, SomeActivity::class.java)
resultLauncher.launch(intent)
}
Advantage:
The new way is reduce complexity which we faced when we call the activity from a fragment or from another activity
Easily ask for any permission and get callback
For those who have problem with wrong requestCode in onActivityResult
If you are calling startActivityForResult() from your Fragment, the requestCode is changed by the Activity that owns the Fragment.
If you want to get the correct resultCode in your activity try this:
Change:
startActivityForResult(intent, 1); To:
getActivity().startActivityForResult(intent, 1);
The ActivityResultRegistry is the recommended approach
ComponentActivity now provides an ActivityResultRegistry that lets you handle the startActivityForResult()+onActivityResult() as well as requestPermissions()+onRequestPermissionsResult() flows without overriding methods in your Activity or Fragment, brings increased type safety via ActivityResultContract, and provides hooks for testing these flows.
It is strongly recommended to use the Activity Result APIs introduced in Android 10 Activity 1.2.0-alpha02 and Fragment 1.3.0-alpha02.
Add this to your build.gradle
def activity_version = "1.2.0-beta01"
// Java language implementation
implementation "androidx.activity:activity:$activity_version"
// Kotlin
implementation "androidx.activity:activity-ktx:$activity_version"
How to use the pre-built contract
This new API has the following pre-built functionalities
TakeVideo
PickContact
GetContent
GetContents
OpenDocument
OpenDocuments
OpenDocumentTree
CreateDocument
Dial
TakePicture
RequestPermission
RequestPermissions
An example that uses the takePicture contract:
private val takePicture = prepareCall(ActivityResultContracts.TakePicture()) { bitmap: Bitmap? ->
// Do something with the Bitmap, if present
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
button.setOnClickListener { takePicture() }
}
So what’s going on here? Let’s break it down slightly. takePicture is just a callback which returns a nullable Bitmap - whether or not it’s null depends on whether or not the onActivityResult process was successful. prepareCall then registers this call into a new feature on ComponentActivity called the ActivityResultRegistry - we’ll come back to this later. ActivityResultContracts.TakePicture() is one of the built-in helpers which Google have created for us, and finally invoking takePicture actually triggers the Intent in the same way that you would previously with Activity.startActivityForResult(intent, REQUEST_CODE).
How to write a custom contract
A simple contract that takes an Int as an input and returns a string that the requested Activity returns in the result Intent.
class MyContract : ActivityResultContract<Int, String>() {
companion object {
const val ACTION = "com.myapp.action.MY_ACTION"
const val INPUT_INT = "input_int"
const val OUTPUT_STRING = "output_string"
}
override fun createIntent(input: Int): Intent {
return Intent(ACTION)
.apply { putExtra(INPUT_INT, input) }
}
override fun parseResult(resultCode: Int, intent: Intent?): String? {
return when (resultCode) {
Activity.RESULT_OK -> intent?.getStringExtra(OUTPUT_STRING)
else -> null
}
}
}
class MyActivity : AppCompatActivity() {
private val myActionCall = prepareCall(MyContract()) { result ->
Log.i("MyActivity", "Obtained result: $result")
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
...
button.setOnClickListener {
myActionCall(500)
}
}
}
Check this official documentation for more information.
If you want to update the user interface with the activity result, you can't to use this.runOnUiThread(new Runnable() {}. Doing this, the UI won't refresh with the new value. Instead, you can do this:
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_CANCELED) {
return;
}
global_lat = data.getDoubleExtra("LATITUDE", 0);
global_lng = data.getDoubleExtra("LONGITUDE", 0);
new_latlng = true;
}
#Override
protected void onResume() {
super.onResume();
if(new_latlng)
{
PhysicalTagProperties.this.setLocation(global_lat, global_lng);
new_latlng=false;
}
}
This seems silly, but it works pretty well.
In Kotlin
Suppose A & B are activities the navigation is from A -> B
We need the result back from A <- B
in A
// calling the Activity B
resultLauncher.launch(Intent(requireContext(), B::class.java))
// we get data in here from B
private var resultLauncher =
registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
when (result.resultCode) {
Activity.RESULT_OK -> {
result.data?.getStringExtra("VALUE")?.let {
// data received here
}
}
Activity.RESULT_CANCELED -> {
// cancel or failure
}
}
}
In B
// Sending result value back to A
if (success) {
setResult(RESULT_OK, Intent().putExtra("VALUE", value))
} else {
setResult(RESULT_CANCELED)
}
It is a very common problem on Android
It can be broken down into three pieces
Start Activity B (happens in Activity A)
Set requested data (happens in activity B)
Receive requested data (happens in activity A)
startActivity B
Intent i = new Intent(A.this, B.class);
startActivity(i);
Set requested data
In this part, you decide whether you want to send data back or not when a particular event occurs.
E.g.: In activity B there is an EditText and two buttons b1, b2.
Clicking on Button b1 sends data back to activity A.
Clicking on Button b2 does not send any data.
Sending data
b1......clickListener
{
Intent resultIntent = new Intent();
resultIntent.putExtra("Your_key", "Your_value");
setResult(RES_CODE_A, resultIntent);
finish();
}
Not sending data
b2......clickListener
{
setResult(RES_CODE_B, new Intent());
finish();
}
The user clicks the back button
By default, the result is set with Activity.RESULT_CANCEL response code
Retrieve result
For that override onActivityResult method
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RES_CODE_A) {
// b1 was clicked
String x = data.getStringExtra("RES_CODE_A");
}
else if(resultCode == RES_CODE_B){
// b2 was clicked
}
else{
// The back button was clicked
}
}
I will post the new "way" with Android X in a short answer (because in some case you does not need custom registry or contract). If you want more information, see: Getting a result from an activity
Important: there is actually a bug with the backward compatibility of Android X so you have to add fragment_version in your Gradle file. Otherwise you will get an exception "New result API error : Can only use lower 16 bits for requestCode".
dependencies {
def activity_version = "1.2.0-beta01"
// Java language implementation
implementation "androidx.activity:activity:$activity_version"
// Kotlin
implementation "androidx.activity:activity-ktx:$activity_version"
def fragment_version = "1.3.0-beta02"
// Java language implementation
implementation "androidx.fragment:fragment:$fragment_version"
// Kotlin
implementation "androidx.fragment:fragment-ktx:$fragment_version"
// Testing Fragments in Isolation
debugImplementation "androidx.fragment:fragment-testing:$fragment_version"
}
Now you just have to add this member variable of your activity. This use a predefined registry and generic contract.
public class MyActivity extends AppCompatActivity{
...
/**
* Activity callback API.
*/
// https://developer.android.com/training/basics/intents/result
private ActivityResultLauncher<Intent> mStartForResult = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(),
new ActivityResultCallback<ActivityResult>() {
#Override
public void onActivityResult(ActivityResult result) {
switch (result.getResultCode()) {
case Activity.RESULT_OK:
Intent intent = result.getData();
// Handle the Intent
Toast.makeText(MyActivity.this, "Activity returned ok", Toast.LENGTH_SHORT).show();
break;
case Activity.RESULT_CANCELED:
Toast.makeText(MyActivity.this, "Activity canceled", Toast.LENGTH_SHORT).show();
break;
}
}
});
Before new API you had :
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(MyActivity .this, EditActivity.class);
startActivityForResult(intent, Constants.INTENT_EDIT_REQUEST_CODE);
}
});
You may notice that the request code is now generated (and hold) by the Google framework.
Your code becomes:
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(MyActivity .this, EditActivity.class);
mStartForResult.launch(intent);
}
});
First you use startActivityForResult() with parameters in the first Activity and if you want to send data from the second Activity to first Activity then pass the value using Intent with the setResult() method and get that data inside the onActivityResult() method in the first Activity.
In your Main Activity
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.takeCam).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent=new Intent(getApplicationContext(),TakePhotoActivity.class);
intent.putExtra("Mode","Take");
startActivity(intent);
}
});
findViewById(R.id.selectGal).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent=new Intent(getApplicationContext(),TakePhotoActivity.class);
intent.putExtra("Mode","Gallery");
startActivity(intent);
}
});
}
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
}
In Second Activity to Display
private static final int CAMERA_REQUEST = 1888;
private ImageView imageView;
private static final int MY_CAMERA_PERMISSION_CODE = 100;
private static final int PICK_PHOTO_FOR_AVATAR = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_take_photo);
imageView=findViewById(R.id.imageView);
if(getIntent().getStringExtra("Mode").equals("Gallery"))
{
pickImage();
}
else {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{Manifest.permission.CAMERA}, MY_CAMERA_PERMISSION_CODE);
} else {
Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_REQUEST);
}
}
}
}
public void pickImage() {
Intent intent = new Intent(Intent.ACTION_PICK);
intent.setType("image/*");
startActivityForResult(intent, PICK_PHOTO_FOR_AVATAR);
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults)
{
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == MY_CAMERA_PERMISSION_CODE)
{
if (grantResults[0] == PackageManager.PERMISSION_GRANTED)
{
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_REQUEST);
}
else
{
Toast.makeText(this, "Camera Permission Denied..", Toast.LENGTH_LONG).show();
}
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CAMERA_REQUEST && resultCode == Activity.RESULT_OK) {
Bitmap photo = (Bitmap) data.getExtras().get("data");
imageView.setImageBitmap(photo);
}
if (requestCode == PICK_PHOTO_FOR_AVATAR && resultCode == Activity.RESULT_OK) {
if (data == null) {
Log.d("ABC","No Such Image Selected");
return;
}
try {
Uri selectedData=data.getData();
Log.d("ABC","Image Pick-Up");
imageView.setImageURI(selectedData);
InputStream inputStream = getApplicationContext().getContentResolver().openInputStream(selectedData);
Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
Bitmap bmp=MediaStore.Images.Media.getBitmap(getContentResolver(),selectedData);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch(IOException e){
}
}
}
You need to override Activity.onActivityResult():
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_CODE_ONE) {
String a = data.getStringExtra("RESULT_CODE_ONE");
}
else if(resultCode == RESULT_CODE_TWO){
// b was clicked
}
else{
}
}

Call method when intent closes

I am making a music player application, and I am trying to implement playlists. I have a file chooser in another intent, and I would like the ListView in the mainActivity to update when the file chooser intent closes. how can I call my UpdateListView method when it closes?
start intent:
Intent intent = new Intent(this, FileChooser.class);
startActivity(intent);
Closing intent
public void closeButton(View view){
finish();
}
Any help would be appreciated! thanks!
I assume you are using your own FileChoser class, not a standard Android one:
private static final int FileChooserRequestCode = 666;
Intent intent = new Intent(this, FileChooser.class);
startActivityForResult(intent, FileChooserRequestCode);
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == FillChooserRequestCode) {
if (resultCode == Activity.RESULT_OK) {
// ... file is chosen
String fileName = data.getStringExtra("FileName");
} else {
... dialog is closed
}
}
}
in FileChoser you do
Intent intent = new Intent();
intent.putStringExtra("FileName", fileName);
SetResult(Activity.RESULT_OK, intent);
finish();
and
SetResult(Activity.RESULT_CANCELED);
finish();
You can use startActivityForResult() please refer the link Getting Results From Activity
static final int FILE_CHOOSER_INTENT = 1; // The request code
...
private void chooseFile() {
Intent intent = new Intent(this, FileChooser.class);
startActivityForResult(intent, FILE_CHOOSER_INTENT);
}
Call setResult pass your result data as Intent. for details refer link SetResult function
Override this in your calling activity
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// Check which request we're responding to
if (requestCode == FILE_CHOOSER_INTENT) {
// Make sure the request was successful
if (resultCode == RESULT_OK) {
// The user picked a contact.
// The Intent's data Uri identifies which contact was selected.
// Do something with the contact here (bigger example below)
}
}
}

Android, Get result from third activity

In first activity, there is empty ListView and Button.
When I press button, it starts second activity that has ListView of categories.
After I click into one of listElements it will start third activity that has ListView with elements that are belong to my chosen category.
When I choose element of third ListView it must send me back to first activity, where my chosen element is added to my empty ListView
Use Intent.FLAG_ACTIVITY_FORWARD_RESULT like this:
FirstActivity should start SecondActivity using startActivityForResult().
SecondActivity should start ThirdActivity using this:
Intent intent = new Intent(this, ThirdActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
startActivity(intent);
finish();
This tells ThirdActivity that it should return a result to FirstActivity.
ThirdActivity should return the result using
setResult(RESULT_OK, data);
finish();
At that point, FirstActivity.onActivityResult() will be called with the data returned from ThirdActivity.
Though I'd implore you to change your architecture design, it is possible to do it like this:
File ActivityOne.java
...
startActivityForResult(new Intent(this, ActivityTwo.class), 2);
...
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if(resultCode == RESULT_OK && data != null) {
//Collect extras from the 'data' object
}
}
...
File ActivityTwo.java
...
startActivityForResult(new Intent(this, ActivityTwo.class), 3);
...
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if(resultCode == RESULT_OK && data != null) {
setResult(resultCode, data);
finish();
}
setResult(RESULT_CANCELLED);
}
...
File ActivityThree.java
...
//Fill the Intent resultData with the data you need in the first activity
setResult(RESULT_OK, resultData);
finish();
...

retrieve value from second activity

In my MainActivity, I launch a second activity:
Button button = (Button) findViewById(R.id.btnPush);
button.setOnClickListener(new View.OnClickListener(){
public void onClick(View view){
Intent nowStart = new Intent(getApplicationContext(), AddPillScheduleActivity.class);
startActivityForResult(nowStart, RESULT_OK);
//startSecond();
}
});
Then inside my Second Activity, I would like to return a value back to the main activity.
Intent i=new Intent();
i.putExtra("ANSWER", ans);
setResult(RESULT_OK,i);
finish();
That seems to execute fine, but back in my MainActivity, I would like to grab the value. This is where I am having trouble. My debugger never stops on my onActivityResult, which is:
#Override
protected void onActivityResult(int requestCode ,int resultCode ,Intent data ) {
super.onActivityResult(requestCode, resultCode, data);
String name = getIntent().getExtras().getString("ANSWER");
if (resultCode == RESULT_OK) {
Toast.makeText(this, name, Toast.LENGTH_LONG).show();
}
Can someone shed a little light? Thanks.
You're not getting the value from the right intent, the one that comes with the method. Modify your code to the following:
#Override
protected void onActivityResult(int requestCode ,int resultCode ,Intent data ) {
super.onActivityResult(requestCode, resultCode, data);
String name = data.getStringExtra("ANSWER");
if (resultCode == RESULT_OK) {
Toast.makeText(this, name, Toast.LENGTH_LONG).show();
}
}
Use the getStringExtra method as you put a String in your intent and not a bundle. Also, not the best practice use the same code for the requestCode and resultCode.
String name = getIntent().getExtras().getString("ANSWER");
is accessing the wrong intent. getIntent() returns the intent that started the activity. You want
String name = data.getExtras().getString("ANSWER");
Also, the second parameter of startActivityForResult() is a request code, so using RESULT_OK -- althought it still works -- is confusing.

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