I've read many answers on the same question but still I do not understand why my code doesn't work properly. I have a problem with (as I think) exchanging data between two activities.
I have 2 activities - the first contains ListView and an Add button.
When user presses Add new activity starts with the form to fill. When user completes the form he/she presses OK and my first activity starts again (it really does) and it should contain new item (but it doesn't).
This is my first activity:
public class DatabaseActivity extends Activity implements OnClickListener {
ArrayList<Student> students;
StudentDatabaseAdapter adapter;
ListView lvStudentList;
ImageButton imgBtnAdd;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.database);
students = new ArrayList<Student>();
fillArrayList();
adapter = new StudentDatabaseAdapter(this, students);
lvStudentList = (ListView)findViewById(R.id.lvStudentsList);
lvStudentList.setAdapter(adapter);
imgBtnAdd = (ImageButton)findViewById(R.id.imagBtnAddStudent);
imgBtnAdd.setOnClickListener(this);
}
public void fillArrayList() {
//code here
}
#Override
public void onClick(View v) {
Intent intent;
intent = new Intent(this, WizardActivity.class);
startActivity(intent);
}
public void addStudent(Student student) {
students.add(student);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
super.onActivityResult(requestCode, resultCode, intent);
if(resultCode==RESULT_OK)
{
if(requestCode==2)
{
if (intent == null) {return;}
Student newStudent = new Student(intent.getStringExtra("name"), intent.getStringExtra("surname"),
intent.getStringExtra("last_name"), Integer.parseInt(intent.getStringExtra("year_of_birth")), R.drawable.default_ava);
addStudent(newStudent);
adapter.notifyDataSetChanged();
}
}
}
}
And that's my second activity:
public class WizardActivity extends Activity implements OnClickListener {
EditText etName, etSurname, etLastName, etYearOfBirth;
ImageButton imgBtnOK;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.wizard);
etName = (EditText)findViewById(R.id.etName);
//initializing other edit texts
imgBtnOK = (ImageButton)findViewById(R.id.imgBtnOK);
imgBtnOK.setOnClickListener(this);
}
#Override
public void onClick(View v) {
Intent intent = new Intent(this, DatabaseActivity.class);
intent.putExtra("name", etName.getText().toString());
intent.putExtra("surname", etSurname.getText().toString());
intent.putExtra("last_name", etLastName.getText().toString());
intent.putExtra("year_of_birth", etYearOfBirth.getText().toString());
setResult(RESULT_OK, intent);
startActivityForResult(intent, 2);
}
}
There is nothing wrong with your notifyDataSetChanged(). You seem to be missing the way a secondary activity communicates results back to its caller activity.
DatabaseActivity.onClick() should call startActivityForResult() instead of startActivity().
WizardActivity.onClick() should just call finish() after setResult() (remove the startActivityForResult() call, it doesn't make sense there). Also notice that the intent you provide to setResult() can be an empty intent, i.e. Intent intent = new Intent();
After the secondary activity finishes, DatabaseActivity will be back to foreground and the result will be processed by DatabaseActivity.onActivityResult().
I think you haven't to start new activity in WizardActivity
try this :
WizardActivity
......
#Override
public void onClick(View v) {
Intent intent = new Intent(this, DatabaseActivity.class);
intent.putExtra("name", etName.getText().toString());
intent.putExtra("surname", etSurname.getText().toString());
intent.putExtra("last_name", etLastName.getText().toString());
intent.putExtra("year_of_birth", etYearOfBirth.getText().toString());
setResult(RESULT_OK, intent);
finish();
}
and in
DatabaseActivity
add if you want
#Override
protected void onResume (){
......
adapter.notifyDataSetChanged();
}
Related
I have an activity that very quickly has to process data and then return to the previous activity, I give an example: I have a MainActivity class that passes information through Intent to another Loader class, this processes the data and sends it back to the MainActivity. I don't know how to put this procedure into practice...
From your MainActivity call the TargetActivity using startActivityForResult()-
For example:
Intent intent = new Intent(this, TargetActivity.class);
intent.putExtra(); // sent your putExtra data here to pass through intent
startActivityForResult(intent, 1000);
In your intent set the data which you want to return back to MainActivity. If you don't want to return back any data then you don't need to set any data.
For example:
In TargetActivity 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 MainActivity class write following code for the onActivityResult() method.
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1000) {
if(resultCode == Activity.RESULT_OK){
String result=data.getStringExtra("result");
}
if (resultCode == Activity.RESULT_CANCELED) {
// Do your task here.
}
}
}
//do Some work
Intent i = new Intent(this,MainActivity2..class);
startActivityForResult(i,12);
}
In MainActivity2.class
// after your work complete
Intent i =new Intent();
i.putExtra("result",true);// any data you want to pass
setResult(RESULT_OK,i);
After this we handle result
protected void onActivityResult(int requestCode, int resultCode, #Nullable Intent data) {
switch(requestCode){
case 12:
if(resultCode == Activity.RESULT_OK){// onsuccess do something
boolean isSucces = data.getBooleanExtra("result",false);
if(isSuccess)// perform action
{// show toast}
}
}
}
I find the best to use callbacks.
in Loader:
Create inner class
MyCallback callback;
viod setCallback(MyCallback callback){
this.callback = callback;
}
viod onStop(){
callback = null;
}
interface MyCallback{
void doSomething(Params params);
}
in MainActivity:
implement MyCallback
set reference in onCreate
Loader loader = new Loader();
loader.setCallback(this);
override method doSomething()
#override
void doSomething(Params params){
//do your thing with the params…
}
when the job is done inside Loader call MainActivity:
callback.doSomething(params);
destroy reference inside MainActivity in onStop()
loader.onStop();
By the help of android startActivityForResult() method, you can get result from another activity.
By the help of android startActivityForResult() method, you can send information from one activity to another and vice-versa. The android startActivityForResult method, requires a result from the second activity (activity to be invoked).
In such case, we need to override the onActivityResult method that is invoked automatically when second activity returns result.
MainActivity.java
public class MainActivity extends Activity {
TextView textView1;
Button button1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView1=(TextView)findViewById(R.id.textView1);
button1=(Button)findViewById(R.id.button1);
button1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
Intent intent=new Intent(MainActivity.this,SecondActivity.class);
startActivityForResult(intent, 2);// Activity is started with
requestCode 2
}
});
}
// Call Back method to get the Message form other Activity
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
// check if the request code is same as what is passed here it is 2
if(requestCode==2)
{
String message=data.getStringExtra("MESSAGE");
textView1.setText(message);
}
}
SecondActivity.java
public class SecondActivity extends Activity {
EditText editText1;
Button button1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
editText1=(EditText)findViewById(R.id.editText1);
button1=(Button)findViewById(R.id.button1);
button1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
String message=editText1.getText().toString();
Intent intent=new Intent();
intent.putExtra("MESSAGE",message);
setResult(Activity.RESULT_OK,intent);
finish();//finishing activity
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.second, menu);
return true;
}
}
I am working on an online radio app demo. I've created an error Activity which I want to take the user to, when an error occurs. In the error page, there is a refresh button, which is supposed to refresh the last Activity where an error occurred. But I don't know how to get the Intent of previous Activity which led to the error page to get it refresh on ButtonClick, I only know to make it return to a particular Activity.
You can use startActivityForResult in both calling activities
In MainActivity.java
int REFRESH = 1;
private void startErrorActivity() {
startActivityForResult(new Intent(this, ErrorActivity.class), REFRESH);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REFRESH) {
//do refresh
}
}
And in ErrorActivity.java
Button button = findViewById(R.id.refreshButton);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
finish(); //this will take you back to calling activities onActivityResult method
}
});
UPDATE:
I honestly think #sneharc's answer is better. Use that.
Try this:
public class ActivityA extends Activity {
public void myFunction(){
try{
// something bad happens here. need to go to ErrorActivity
}
catch (SomeException e){
Intent startErrorActivityIntent = new Intent(this, ErrorActivity.class);
startErrorActivityIntent.putExtra("sourceActivity", ActivityA.class.getSimpleName())
startActivity(this, startErrorActivityIntent)
}
}
}
public class ActivityB extends Activity {
public void myFunction(){
try{
// something bad happens here. need to go to ErrorActivity
}
catch (SomeException e){
Intent startErrorActivityIntent = new Intent(this, ErrorActivity.class);
startErrorActivityIntent.putExtra("sourceActivity", ActivityB.class.getSimpleName())
startActivity(this, startErrorActivityIntent)
}
}
}
public class ErrorActivity extends Activity {
private Intent mReceivedIntent;
#Override
protected void onCreate(Bundle savedInstanceState) {
mReceivedIntent = getIntent();
}
public void onClickRefresh(){
String retryActivityName = mReceivedIntent.getStringExtra("sourceActivity");
Intent retryActivityIntent = null;
if (!TextUtils.isEmpty(retryActivityName)){}
if (retryActivityName.equalsIgnoreCase(ActivityA.class.getSimpleName()))
retryActivityName = new Intent(this, ActivityA.class);
if (retryActivityName.equalsIgnoreCase(ActivityB.class.getSimpleName()))
retryActivityName = new Intent(this, ActivityB.class);
}
if (retryActivityIntent != null)
startActivityForResult(this, retryActivityIntent);
}
}
Let's consider the following situation:
Activity A opens Activity B. Now, A is in activity stack. B downloads any data from the Internet and, basing on that data, we conclude that when user come back to the A ( after press back) A should refresh its content. How to say: B: Hey A in stack, please remember that you should refresh your content. I see that I can set some flag in App instance, but, it seems to be weird.
Consider using startActivityForResult in your ActivityA to call ActivityB, then within your ActivityB, override onBackPressed() method and call setResult() based on downloaded data. Finally back into your ActivityA override onActivityResult(int requestCode, int resultCode, Intent data)
Use the following example as guide:
ActivityA.java
public class ActivityA extends AppCompatActivity {
#Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent intent = new Intent(this, ActivityB.class);
startActivityForResult(intent, 1234);
}
#Override
protected void onActivityResult(final int requestCode, final int resultCode, Intent intent) {
if (1234 == requestCode) {
if (resultCode == Activity.RESULT_OK) {
Toast.makeText(this, "Do action 1", Toast.LENGTH_SHORT).show();
}
if (resultCode == Activity.RESULT_CANCELED) {
Toast.makeText(this, "Do action 2", Toast.LENGTH_SHORT).show();
}
}
}
}
ActivityB.java
public class ActivityB extends AppCompatActivity {
#Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
public void onBackPressed() {
final Intent intent = new Intent();
if (true) { //Replace this condition by yours based on downloaded data
setResult(Activity.RESULT_OK, intent);
} else {
setResult(Activity.RESULT_CANCELED, intent);
}
super.onBackPressed();
}
}
Not that way. Always update Activity A content in the onResume() method of A activity.
I've got a class which handles a question sequence. It doesn't extend Activity. In the class there is the method:
public class QuizMaster {
public void startQuiz(Activity activity, Model model) {
//switch - case statement using model
Intent intent = new Intent(activity, QuestionTextActivity.class)
activity.startActivityForResult(intent, requestCode);
//other case statements with other intents
}
}
When I call this method from a working activity with
mQuizMaster.startQuiz(this, mModel);
And I finish() the child activity:
Intent returnIntent = new Intent();
returnIntent.putExtra(ARG_SELECTED_CHECKBOX, checkedBox);
setResult(RESULT_CODE, returnIntent);
finish();
it doesn't execute the parent activity's
#Override
protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
Log.d(LOG_TAG, "OnActivityResult called in SignDetailsActivity. Resultcode is: ");
}
But when I execute the
Intent intent = new Intent(activity, QuestionTextActivity.class)
activity.startActivityForResult(intent, requestCode);
in the actual parent activity file, it does execute the onActivityResult method.
Why doesn't the child activity run the onActivityResult in the parent activity if sent with a non-activity class? How do i fix this?
I haven't found anyone with the same problem with executing new Intent() in a non-activity class like this. If there is someone, i didn't use the right search keywords and some others might type in the same as I did and come on this page.
You need to call setResult(int) before call finish(). This is from Activity documentation:
When an activity exits, it can call setResult(int) to return data back
to its parent. It must always supply a result code, which can be the
standard results RESULT_CANCELED, RESULT_OK, or any custom values
starting at RESULT_FIRST_USER. In addition, it can optionally return
back an Intent containing any additional data it wants. All of this
information appears back on the parent's Activity.onActivityResult(),
along with the integer identifier it originally supplied.
Here is my implementation, which worked:
MainActivity.java (parent activity)
public class MainActivity extends AppCompatActivity {
private Sample sample;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn = (Button) findViewById(R.id.button);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
sample = new Sample();
sample.startActivity(MainActivity.this);
}
});
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
Log.d("TEST", "DONE");
}
}
LaunchActivity.java (child activity)
public class LaunchActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_launch);
Button btn = (Button) findViewById(R.id.button2);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
setIntent(new Intent());
finish();
}
});
}
}
Sample.java (class start activity)
public class Sample {
public Sample () {}
public void startActivity (Activity a) {
Intent it = new Intent(a, LaunchActivity.class);
a.startActivityForResult(it, 0);
}
}
Consider i am using five screen pages for project "A".Each page is having switching between other pages sequentially one by one,my need is to do close all the page when i am clicking the button "exit" from the page five which is the last one.
I have used this below code,but the problem is only the last page is getting close others are not.
find my code below
Button extbtn = (Button)findViewById(R.id.but_Exit);
extbtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent();
setResult(RESULT_OK, intent);
finish();
} });
Thanks for your time!
Make all five activities extend a BaseActivity that registers a BroadcastReceiver at onCreate (and unregisters at onDestroy).
When extbtn is clicked, send a broadcast to all those BaseActivities to close themselves
for example, in your BaseActivity add:
public static final String ACTION_KILL_COMMAND = "ACTION_KILL_COMMAND";
public static final String ACTION_KILL_DATATYPE = "content://ACTION_KILL_DATATYPE";
private KillReceiver mKillReceiver;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
...
mKillReceiver = new KillReceiver();
registerReceiver(mKillReceiver, IntentFilter.create(ACTION_KILL_COMMAND, ACTION_KILL_DATATYPE));
}
#Override
protected void onDestroy() {
super.onDestroy();
unregisterReceiver(mKillReceiver);
}
private final class KillReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
finish();
}
}
and at extbtn's onClick call:
extbtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// send a broadcast that will finish activities at the bottom of the stack
Intent killIntent = new Intent(BaseActivity.ACTION_KILL_COMMAND);
killIntent.setType(BaseActivity.ACTION_KILL_DATATYPE);
sendBroadcast(killIntent);
Intent intent = new Intent();
setResult(RESULT_OK, intent);
finish();
}
});