Develop Reference

Back Button in ActionBar of App

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

returning back to main activity from SettingActivity

I got SettingActivity from AndroidStudio Gallery, which uses ActionBar. Everything is fine when I click back button from ActionBar inside SettingsActivity. But when I want to return to main activity using this button in ActionBar nothing happens.
My SettingsActivity uses headers for preferences, so I thought I can check whether I am "inside" any of these headers, and if answer is none then I am in main setting screen and I can call main activity using startActivity(this,MainActivity.class). But problem is I cann't determine whether I am in start screen or in some header. Of course if there are more easy ways to do it I would appreciate it very much.

to make action bar back press return back , you have to do it in menu item selected
#Override
public boolean onOptionsItemSelected(MenuItem menuItem) {
switch (menuItem.getItemId()) {
case android.R.id.home:
Intent homeIntent = new Intent(this, HomeActivity.class);
homeIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(homeIntent);
}
return (super.onOptionsItemSelected(menuItem));
}

Lollipop activity transitions: Back button vs. back from toolbar differences?

I have an app where I'm doing activity transitions for a company directory. When a search result is selected, the animation of their photo to the detail screen works. And if I hit the back button, the reverse animation occurs. However, if I hit the back arrow from the Toolbar, the reverse animation never occurs.
The detail screen is a new DetailActivity with a single fragment in it called DetailFragment. I'm not doing anything special on "onBackPressed". Should I be?

If you want the return transition to play, you'll need to listen for the up-navigation button click and call finishAfterTransition() directly:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
finishAfterTransition();
return true;
}
return super.onOptionsItemSelected(item);
}

Get Actionbar click event xamarin.android

Im have added a back icon to the action bar,now when i click on that i need to go back to the activity that started it.Is there a actionbar click event which i can hook to and call the this.finish method

In order to work the home button properly and capture it's action event. You must have to first enabled the home button by calling setHomeButtonEnabled() for targeting android API level 14 onwards.
ActionBar actionBar = getSupportActionBar();
actionBar.setHomeButtonEnabled(true);
Now you've to override the onOptionsItemSelected method inside your activity to capture the home button action of actionbar and also "Back" key on some of the android devices.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
finish(); // this will dismiss the current activity
}
return true;
}

Android - actionBar.setDisplayHomeAsUpEnabled issues

In my activity which extends SherlockFragmentActivity I have action bar and have also set actionBar.setDisplayHomeAsUpEnabled(true) to come back to my previous activity. Everything works fine. But when i click on home button, the background color should be applied only to the app icon but it also applies to the "title" on action bar as shown in screen shot. I dont want this to happen. When i click on home button, only the app icon should be click able(background color should be applied only for app icon) and not the title. Any idea how can i do this?
my activity code:
ActionBar actionBar = getSupportActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setTitle(some_string);

Don't forget this part, because that home button is also a MENU button.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// This is called when the Home (Up) button is pressed in the action bar.
// Create a simple intent that starts the hierarchical parent activity and
// use NavUtils in the Support Package to ensure proper handling of Up.
Intent upIntent = new Intent(this, MainActivity.class);
if (NavUtils.shouldUpRecreateTask(this, upIntent)) {
// This activity is not part of the application's task, so create a new task
// with a synthesized back stack.
TaskStackBuilder.from(this)
// If there are ancestor activities, they should be added here.
.addNextIntent(upIntent)
.startActivities();
finish();
} else {
// This activity is part of the application's task, so simply
// navigate up to the hierarchical parent activity.
NavUtils.navigateUpTo(this, upIntent);
}
return true;
}
return super.onOptionsItemSelected(item);
}

The standard Android UI pattern is to include the title in the pressed state.
However, I think if you followed this link (describing how to add a custom view to the left of an actionbar) How to align items in action bar to the left? , and set the title to empty. The below code worked on my local device
ActionBar action=getActionBar();
action.setDisplayShowCustomEnabled(true);
action.setHomeButtonEnabled(true);
action.setDisplayShowTitleEnabled(false);
TextView title =new TextView(getApplicationContext());
title.setText("Your Title here");
title.setGravity(Gravity.LEFT | Gravity.CENTER_VERTICAL);
action.setCustomView(title);