In an given Android activity, I would like to start a new activity for the user at some point. Once they leave the first activity and arrive at the second, the first activity is hidden..
Now my question is
I want to bring back the first activity (i dont want to create a new instance of the first activity but to bring back the already existing instance of the first activity) when a button is clicked in the second activity ...
thanks :)
so simple. integrate the below code in your second activity
Button b = (Button)findViewById(yourbuttonid here);
b.setOnClickListener(new View.onClickListener(){
public void onClick(View v){
finish();
}
});
This will work
You would define the first activity with launchMode="singleInstance", then you would start the activity as usual.
Depending on the usage of your second activity, you could also use startActivityForResult() when you start your second activity...
FirstActivity.java{
private static final int SECOND_ACTIVITY = 0;
openSecondActivity(){
Intent forChildIntent= new Intent( this ,FirstActivity. class );
//data for second activity
forChildIntent.putExtra("userName", getUsrName());
this.startActivityForResult(forChildIntent, SECOND_ACTIVITY);
}
protected void onActivityResult(int requestCode, int resultCode, Intent data){
switch (resultCode) {
case RESULT_OK: //do something
default:break;
}
}
SecondActivity.java{
goBackButtonClick(){
Intent retData=new Intent();
//set data to pass back ,if required
//retData.putExtra("userName", getUsrName());
setResult(RESULT_OK, retData);
finish();//will take you to the first activity
}
}
Related
My mainActivity contains 5 fragments which you can switch through with tabs. The main tab shown on start is the third one (the one in the middle). I have a button in fragment #1 which opens activityTwo. What should I put in the onBackPressed method in activityTwo in order for it to bring me back to mainActivity with selected tab #1. I currently have this, but it opens mainActivity and shows the main tab (#3)
#Override
public void onBackPressed() {
Intent intent = new Intent(this, MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
startActivity(intent);
ActivityTwo.this.finish();
}
How can I make it show tab #1 instead of tab #3?
Your first activity should still be on the activity stack, so you should not call startActivity again. Instead, you can use setResult to pass a value back to your first activity:
// Inside your second activity
#Override
public void onBackPressed() {
setResult(RESULT_OK);
finish();
}
Then, from your first activity, replace startActivity with startActivityForResult, with a request code (any integer you want, as long as it's unique):
startActivityForResult(intent, YOUR_REQUEST_CODE);
Then override onActivityResult:
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == YOUR_REQUEST_CODE) {
if (resultCode == RESULT_OK) {
// Code to select tab 1 here
// mTabLayout.getTabAt(0).select();
}
}
}
i think you are using view pager , so while you return from activity 2, use viewPager.setCurrentItem(page);
where page will be your tab no, (in this case it will be 2, since it starts with 0). Hope this helps, if not then please clarify a bit more.
In my app, there are 3 activities and their calling sequence is like this...
Splash activity--->Dashboard Activity--->List Activity
If it goes like this then If I press back button on List activity then it will follow the reverse sequence of above.
There is one requirement where user can navigate to List Activity directly from Splash (Skipping Dashboard Activity) Now when user will hit back button on List Activity then I wan't to show Dashboard Activity which is not there in the Activity Stack.
So please help me with the best approach.
Pass a boolean through the intent for going to List Activity from either of the others. Using onBackPressed check if the boolean is true or false for skipping Dashboard Activity.
Then if true put new intent for loading dashboard activity and finish(); on list activity.
You have to pass class name as intent extra from both Splash and DashboardActiviy.
In List Activity you have to get the class name using getIntent().
When the user click back button, you need to check the class name based on that you can take decision.
if(name.equalIgnorecase(DashboardActivit.class.getSimpleName()){
//Add your intent
}else{
//
}
This may give you definite solution to you.Give a try
you can directly go to splash from list Activity while going to
ListActivity from Dashboard Activity call finish()
Intent i = new Intent(DashboardActivity.this,ListActivity);
startActivtiy(i);
finish();
Start your inner activities with startAcvitiyForResult
Intent i = new Intent(this, Activity_2.class);
startActivityForResult(i, 1);
and in your inner activity
#Override
public void onBackPressed ()
{
finish();
}
You can also do stuff in your outer activity as you like after your inner activity finishes
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1) {
if(resultCode == 1){
Log.i("TEST", "RESULT_OK");
}
else {
return;
}
}
}
I have a main activity A -> call activity B -> call activity C -> call activity D.
Activity is called by startActivity(intent).
Activity D have a "Close" button.
How to I notify to Activity A when hit "close" button on Activity D?
Any help is appreciated.
Try this:
Use SharedPreference to store the status of button in Activity D.
In activity A under onResume() get the status of button from the SharedPreference.
//* start the activity with enum defined int activity D to identify your activity
startActivityForResult(intent, DActivity.D_REQUEST_CODE);
//in your D activity define this
private static final int D_REQUEST_CODE = 1;
//* when the button is clicked to close in your D activity, call this in the button event listner
setResult(Activity.RESULT_OK, intent);
//* implement this in your A activity
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
if(data==null)return;
if (requestCode == DActivity.D_REQUEST_CODE)
{
switch (resultCode)
{
case Activity.RESULT_OK:
//* do something
break;
default:
break;
}
}
findViewById(R.id.button_close).setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(this, Activity_A.class).setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK));
}
});
This will work if you are looking to simply show Activity A while clearing the activity stack. If you just want to know when you return to Activity A, you can save status in SharedPrefs as answered above.
Can you please clarify me, what's the best practice for this example:
Activity1 does INSERTS on SQLite and starts Activity2.
On Activity2, the user clicks on Back button and goes back to Activity1.
But instead of making INSERT, I want to make UPDATE to the data on SQLite.
How do I control, that user "came" back?
What's the best practice?
Assume on button click you starting Activity 2
public static final int YOURCONSTANTNUMBER = 77;
//Button Value
Button second = (Button)findViewById(R.id.firstButton);
second.setOnClickListner(this);
#Override
public void onClick(View v)
{
switch(v.getId())
{
case R.id.btnSecondActivity:
//Code for inserting data into database
Intent secondactivity = new Intent(FirstActivity.this, SecondActivity.class);
startActivity(secondactivity);
break;
}
}
In your second activity
To take control over the back button use the below code
#Override
public void onBackPressed()
{
//Code for update
}
EDIT
Call your second activity with startActivityForResult() method which will let you know the result.
In First Activity
Intent secondactivity = new Intent(FirstActivity.this, SecondActivity.class);
startActivityForResult(secondactivity,YOURCONSTANTNUMBER);
Getting Result
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch(requestCode)
{
case YOURCONSTANTNUMBER:
// It will execute if you returning from second activity
//Update you database here
}
}
In Your Second Activity
Call this method were appropriate setResult(YOURCONSTANTNUMBER);
Hope it helps
Assuming you want to do both DB operations in Activity1, consider startActivityForResult() here:
http://developer.android.com/reference/android/app/Activity.html#startActivityForResult(android.content.Intent, int)
I have one activity A, that has one button and one list view which shows names of books . on click of the button, activity B starts, there user fill the book form and save it . when he press back button , user comes to activity A. Here the book name should be updated in listview. I think I have to write some code in onResume() . Can u please tell me what to write. I am using customised list view.
Start activity B with startActivityForResult() and use method onActivityResult() to restart or process the new data
For example, to start Activity B:
String callingActivity = context.getLocalClassName();
Intent newActivity = new Intent(getApplicationContext(),ActivityB.class);
newActivity.setData(Uri.parse(callingActivity));
startActivityForResult(newActivity, 0);
Then somewhere in your Activity A class:
protected void onActivityResult(int requestCode, int resultCode, Intent data){
if(requestCode == 0){
// do processing here
}
}
The other answers should suffice, but onResume() can be called in cases where the activity is resumed by other means.
To simply restart Activity A when user presses back button from Activity B, then put the following inside the onActivityResult:
if(requestCode == 0){
finish();
startActivity(starterintent);
}
And in the onCreate of Activity A, add starterintent = getIntent();
Just remember to initiate the variable with Intent starterintent; somewhere before your onCreate is called.
e.g.
public class ActivityA extends ListActivity {
Intent starterintent;
public void onCreate(Bundle b){
starterintent = getIntent();
}
protected void onActivityResult(int requestCode, int resultCode, Intent data){
if(requestCode == 0){
finish();
startActivity(starterintent);
}
}
private void startActivityB(){
String callingActivity = context.getLocalClassName();
Intent newActivity = new Intent(getApplicationContext(),ActivityB.class);
newActivity.setData(Uri.parse(callingActivity));
startActivityForResult(newActivity, 0);
}
}
Then just call startActivityB() from a button click or whatever
YES you are right. Write code in onResume.
When you updated date just call notifyDataSetChanged(); for your ListView adapter
Hope, it help you!
You can either start the activity when user press on Save, and it will fix it for you.
Or if you want to press back:
#Override
public void onResume(){
super.onResume();
list.clear();
list.addAll(getBooks());
adapter.notifyDataSetChanged();
}