Develop Reference

How to go back to previous activite(s)?

so i have Activity A,B, and C. Activity A & B both go to activity C. When i am on activity C and I press the back home button on mySupportActionBar, I want to return to the state of activity (from the state i left it in) I came from. How would i accomplish this?
Here is my onOptionsItemSelected(). So currently, it goes back to the designated parent activity i assigned in manifest to avoid my app from crashing. Because the parent activites require strings from intents.
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
int id = item.getItemId();
if(id == android.R.id.home)
{
NavUtils.navigateUpFromSameTask(this);
}
return super.onOptionsItemSelected(item);
}
I would also love to accomplish this onBackPressed().

The back arrow button is the "home" button when you're in a inner activity so you could finish the inner activity or maybe just call the back button
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
default:
return super.onOptionsItemSelected(item);
}
}

Use android.R.id.home
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
finish();
return true;
default:
return super.onOptionsItemSelected(item);
}
}

You also can use setNavigationOnClickListener on toolbar to trigger back button.
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_filter_category);
setSupportActionBar(toolbar);
if (getSupportActionBar() != null) {
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowTitleEnabled(false);
//back button action
toolbar.setNavigationOnClickListener(view -> finish());
}
}

Toolbar back button does not close current Fragment

I have an activity that loads a Fragment onCreate. And I have a toolbar on that activity that has a button that when clicked will add a new Fragment on top of the one that got created first.
Now on that toolbar, when clicked, I want to remove the newer fragment so that it just displaces the fragment that is in the bottom (older one). I've searched and I kinda have figured it out except for one thing.
I did this so that it tries to see if the toolbar button is pressed:
#Override
public boolean onKeyUp(int keyCode, KeyEvent objEvent) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
onBackPressed();
return true;
}
return super.onKeyUp(keyCode, objEvent);
}
#Override
public void onBackPressed() {
FragmentManager mFM = getSupportFragmentManager();
if(mFM.findFragmentByTag("NewFragment") != null){
mFM.beginTransaction().remove(mFM.findFragmentByTag("NewFragment")).commit();
}
}
The problem is, "keyCode" is only equals to KEYCODE_BACK when you click the "hardware's back button" and not the back button of the toolbar. What it gives me is keycode 58 and not 4 (KEYCODE_BACK).

I believe what your looking for is the NavigationListener for the Toolbar Widget:
mToolbar.setNavigationOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onBackPressed();
}
});
but if your using a Theme with an ActionBar and setting a supportActionBar then do something :
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch(item.getItemId()){
case android.R.id.home:
onBackPressed();
break;
}
return true;
}

It's not clear from your question whether you're asking a Fragment management question (FragmentTransaction remove vs. replace), or a Toolbar button question. I assume the latter...
An Android Toolbar or ActionBar should have actions handled using:
#Override
public Boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case MY_BACK_BUTTON:
myBackPressedHandler();
return (true);
}
return (false);
}
this assumes that your Back button is added as a MenuItem and was given an ID of MY_BACK_BUTTON.
For a Toolbar, you can use a MenuItemClickListener to handle the click events:
mToolbar.setOnMenuItemClickListener(MenuItem menuItem)
{
#Override
public Boolean onMenuItemClick(MenuItem menuItem)
{
// call onOptionsItemSelected, or handle the click here directly
return (thisFragment.onOptionsItemSelected(menuItem));
}
});
If you're referring to the "Up" button on the Toolbar/ActionBar, i.e. setDisplayHomeAsUpEnabled(true), this will have a getItemId() of android.R.id.home and can be handled in a similar fashion:
case android.R.id.home:
myBackPressedHandler();
return (true);

Going back to the previous activity and fragment from an additional back button

I have an app with tab navigation between fragments. One of these fragments has an option to open a new activity. When I use the built in device back button from this activity it goes back to the tabbed activity with the previous fragment tab selected.
I have added a back button to the action bar of an activity in my app by using:
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
and setting the parent activity in the manifest, but this button always navigates back to the first tab of the parent activity, rather than the one that was previously visible.
How can I make this back button behave in the same way as the device back button?

Do something like this:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
switch(id) {
case android.R.id.home:
onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);
}
onBackPressed() method:
#Override
public void onBackPressed() {
super.onBackPressed();
}

Handle back event in this manner
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
switch(id) {
case android.R.id.home:
onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);
}
in back press method
#Override
public void onBackPressed() {
Intent intent = new Intent(SecondActivity.this,TabbedActivity.class);
intent.putExtra("IsBack",true);
startActivity(intent);
}
in your tabbed activity
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tabs);
if(getIntent().getExtras().getBoolean("IsBack")){
//navigate to your desire fragment
}
}

onOptionsItemSelected not called when pressed back button on Action bar - Android

When I press the back button of my action bar, the method onOptionsItemSelected of my fragment it never called. I want to go to the previous fragment when I pressed the button but this method it never calls. This is the code for the Fragment, what it could be the problem?
public class MyFragment extends Fragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
((ActionBarActivity)getActivity()).getSupportActionBar().setDisplayHomeAsUpEnabled(true);
((ActionBarActivity)getActivity()).getSupportActionBar().setDisplayShowHomeEnabled(true);
setHasOptionsMenu(true);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Get item selected and deal with it
switch (item.getItemId()) {
case android.R.id.home:
//called when the up affordance/carat in actionbar is pressed
getActivity().onBackPressed();
return true;
}
return false;
}
Thanks in advance.

First of all this will be received in base activity not fragment.Add your previous fragment to back stack.And from this fragment popup
if(id==android.R.id.home)
{
getSupportFragmentManager().popBackStack();
}
And to check from which fragment it has been called use:
if (fragment instanceof MyFragment)You're done!!

android default Back button minimizes the application after I implement code for action bar back button

I have implemented code for action bar button and it works fine but after that my smart phone back button is closes or minimizes when I press it. Here is my Code
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_about);
/**
* Action Bar Back Button
*/
getActionBar().setDisplayHomeAsUpEnabled(true);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// Respond to the action bar's Up/Home button
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onBackPressed() {
moveTaskToBack(true);
AboutActivity.this.finish();
}

public void onBackPressed() {
moveTaskToBack(true);
AboutActivity.this.finish();// you are finishing the activity
}
if you want to go back try this
#Override
public void onBackPressed()
{
// code here to show dialog
super.onBackPressed(); // optional depending on your needs
}