I have an application that has a menu and depending on what button you press in the menu a new activity is opened. I want to have a back button on every screen that will bring you to the previous screen so I'm wondering how do I go about this?
Here is some code I have used that works:
backButton = (ImageButton) findViewById(R.id.back_button);
backButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
finish();
}
});
However its not good programming practice for me to put this code in all my activities. How do I go about creating some kind of stack that saves all the pages viewed and using that to return to the previous page?
I have to put a back button in my application so I cannot use the existing one in the ActionBar.
just an Idea
Create a baseClass which extends Activity. In there declare
#Override
public void onClick(View v) {
super.onBackPressed(); // or super.finish();
}
In all activity extend this Base Class. And in every layout in the button put
android:onClick="onClick"
And to make the xml design of button reusable create it in a separate xml. and add it using <include/>
Have you tried using action bar in your activity ? use in every activity
ActionBar actionBar = getSupportActionBar();
if(actionBar != null){
actionBar.setTitle(getResources().getString(R.string.app_name));
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setIcon(R.drawable.app_icon);
}
and handle in
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
finish();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
I would suggest against having a custom back button. Android has a hardware back button. Pressing the haradware back button will navigate to the previous.
I don't think you need a custom back button. I don't think its a good programming practice to override the default behaviour.
You create a backbutton in your activity and implementing the functionality as you have done above. Still the user can use the hardware back button for the same functionality. So you would be providing the same functionality which is redundant.
There is a hardware back button on all android devices, and it does exactly what your lines of codes do, unless overridden to do something else.
You can refer to this answer as well.
I had a similar issue where I was using a back button "Cancel" and a home screen "homeActivity". I ended up solving it using this:
CancelButton = (Button) findViewById(R.id.cancel_button);
CancelButton.setOnClickListener(new OnClickListener() {
public void onClick(View view) {
Intent homeActivity = new Intent(getApplicationContext(), DeviceListActivity.class);
startActivity(homeActivity);
finish();
}
});
In kotlin
backButton!!.setOnClickListener(View.OnClickListener {
onBackPressed()
})
Related
I used below code to close activity after back button pressed.
#Override
public void onBackPressed()
{
super.onBackPressed();
finish();
}
after 5 time pressed it worked
how to solve it ?
remove super.onBackPressed(); to avoid handling the back button by the class parents
If you want to finish when back press. don't need to Override.
#Override
public void onBackPressed()
{
// do something
}
this will do nothing when you press back button.
onBackPressed() usually needed when you want make custom ask to close dialog when back press.
I am beginner in android and I am working on a small project.
There is multiple fragment in that and I'd like to add a back button in fragment to go back.
How can i do that?
create a back button in your fragment layout, then get a reference of it in your fragment class as shown below.
Button backButton = (Button)layout.findViewById(R.id.back_button);
backButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
getActivity().onBackPressed();
}
});
Generally switching from one activity to another activity hamburger icon is replaced with back arrow. I want to control the functionality of that arrow. I have seen many contents here but most of them were related to hardware's back button. How can I control that?
I am trying the functionality in case of fragments. Also I have Navigation drawer attached with the hamburger icon.
I tried this-
if(id == android.R.id.home){
getSupportFragmentManager().beginTransaction().replace(R.id.main_container, new AmbulanceMap()).commit();
getSupportActionBar().setTitle("Book A Ride");
getSupportActionBar().setDisplayHomeAsUpEnabled(false);
}
but doesnt work as I hoped.
I want my back button to change the fragmentto previous fragment.
I had the same problem once. Just like you, things like checking if Android.R.id.home is clicked didn't work.
But I solved it using that:
Set navigation listener to toolbar:
toolbar.setToolbarNavigationClickListener(v -> onBackPressed());
If it should be within fragment:
Create an public method in activity.
In fragment's onAttach (or later) cast getActivity() to your activity and call method you was defined previously.
Example:
// YourActivity
public void setHomeListener(OnLickListener listener){
toolbar.setToolbarNavigationClickListener(listener);
}
//Fragment's onCreate
((YourActivity)getActivity()).setHomeListener(v -> onBackPressed());
//Fragment's onDestroy
((YourActivity)getActivity()).setHomeListener(null);
And, of course, set home us up enabled to show back arrow.
EDIT
if you don't use labmdas u should use:
(YourActivity)getActivity()).setHomeListener(new OnClickListener() {
#Override
public void onClick(View v) {
YourFragment.this.onBackPressed();
}
});
The back button of the ActionBar is a menuItem so you need to override onOptionsItemSelected like this:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case android.R.id.home:
//Your back button logic here
break;
}
return true;
}
Also don´t forget to add getSupportActionBar().setDisplayHomeAsUpEnabled(true); after setting the Toolbar
I am making a contact list application, and i have a main screen that helps you save a contact. I have a search button there. Then i created another UI that i call it search screen. When i click on the search button on main screen, i want to be redirected to the other UI, i.e. search screen. I am planning to add setOnClickListener method for search button but how can i switch from main screen to search screen when i click the button?
btn_goSearch.setOnClickListener(new OnClickListener() {
?????????
}
});
Thanks
#Override
public void onClick(View v) {
Intent intent = new Intent(Currentactivity, YourSearcgActivity.class);
intent.putExtra("EXIT", false);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
}
you should create another Activity, maybe call it SearchActivity, and when the user clicks the button, just start SearchActivity with a simple intent, that will load its own layout and everything:
startActivity(new Intent(context,SearchActivty.class));
I'm using the Actionbar and it's "up" button to return from a detail activity to the main activity, which works fine. Similarly, the user can press the system "back" button to return to the main activity.
In my main activity, in onCreate() data is downloaded from the internet to display upon app start. I noticed that when I use the Actionbar "up" button to go from detail to main activity, onCreate() is run, re-downloading the data. But onCreate() is not run when I use the system "back" button, therefore immediately showing the main activity view.
The code I use in the detail activity to implement the "up" button is:
switch (item.getItemId()) {
case android.R.id.home:
Intent intent = new Intent(this, MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
return true;
I would like the "up" button to behave like the "back" button and not rerun onCreate(). But I'm unsure how to make this happen, or which code path the "back" button implements to return to the main activity.
Thanks!
Instead of starting a whole new activity simply finish the details activity you are in
switch (item.getItemId()) {
case android.R.id.home:
finish();
return true;
Then you will return to the previous activity on the activity stack (your main activity) and onCreate shouldn't be called
If you want Up to do exactly what Back does, you can do this:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch(item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
default:
break;
}
return super.onOptionsItemSelected(item);
}
Note that the default implementation of onBackPressed() just calls finish(), but onBackPressed can be overridden.
I think a better solution can be found in this post.
Calling finish() works in specific situations but may not always produce the behavior described in the documentation e.g:
By calling
Intent intent = NavUtils.getParentActivityIntent(this);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_SINGLE_TOP);
NavUtils.navigateUpTo(this, intent);
you'll return to the parent activity in the state in which you left it. If you have a flat app structure, it'll still act just like the Back button.
for a real "home" functionality , you should see the api demos ,under "App/Activity/Reorder Activities" .
the reason : what if you have something like this : activity1->activity2->activity3 , and now you wish to go to activity1 by pressing the home button on the action bar?
I believe the simplest way is to override the "getParentActivityIntent" method of the detail activity adding the flag "Intent.FLAG_ACTIVITY_CLEAR_TOP":
#Nullable
#Override
public Intent getParentActivityIntent() {
Intent intent = super.getParentActivityIntent();
if (intent != null) {
return super.getParentActivityIntent().addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
}
return intent;
}
There is another solution which can be in hand for somebody. I had the same double-behavior when user pressed Back and ActionbarBack buttons. I was fine with Back btn behaviour. I didn't want an activity to be recreated. So I overrode the method
#Override
public boolean onSupportNavigateUp() {
onBackPressed();
return true;
}
Works fine for me