Develop Reference

How to go back from 3rd activity to second activity by back button?

I just started android programming and I created 3 activities.A button in each activity will open another.I can navigate from my 2nd activity back to my first but I can't navigate from my third activity back to my second.Here's what I tried but the app crashes when I click on the back button. I guess it's trying to jump from the third activity to the second. If it helps my second activity's java file is called CountryDetails.java
public class WikiPage extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_web);
getSupportActionBar().setTitle(R.string.title_activity_wikipedia_details);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
return 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);
}
}

Simply call onBackPressed() instead of NavUtils.navigateUpFromSameTask(this)

Remove NavUtils.navigateUpFromSameTask(this);
You should use onBackPressed() only.
Called when the activity has detected the user's press of the back
key. The default implementation simply finishes the current activity,
but you can override this to do whatever you want.
case android.R.id.home:
onBackPressed();
return true;

Use onBackPressed() instead of NavUtils.navigateUpFromSameTask(this) for activity backstake manage

Back button as Menu in fragment

I want to add a back button as menu in the left of the action bar in fragment. But I don't want the back arrow as my icon.
actionBar.setDisplayHomeAsUpEnabled(true);
The above code line gives the back arrow symbol. Instead i want to use some custom image. Also using that custom image should get it back to its previous activity.

I added something like:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
getActivity().onBackPressed();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
It worked for me.

Add this to your theme in styles.xml:
<item name="android:homeAsUpIndicator">#drawable/my_icon</item>
It will override the default icon. By default it uses the following id:
android.R.id.home
You can use this id to navigate back to your previous activity:
View homeView = getActionBar().getCustomView().findViewById(android.R.id.home);
homeView.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v)
{
//Go back
}
});
or
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// Respond to the action bar's Up/Home button
case android.R.id.home:
//Return back to your activity!
return true;
}
return super.onOptionsItemSelected(item);
}
For more information check the official documentation at : https://developer.android.com/training/implementing-navigation/ancestral.html

Dynamic parent activity for Android up \ back navigation in Preferences menu

I've a Preference activity for a options menu in my Android app.
I've enabled the Up \ Back navigation on the ActionBar and I need to come back to the previous activity that called the Options menu.
For the Preference activity, I could use in the manifest:
android:parentActivityName="mypackage.com.MainActivity"
but how come back to other activies ? The Options menu is called from 4 different activities.
public class Prefs extends PreferenceActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preferences);
ActionBar actionBar = getActionBar();
// Enabling Up / Back navigation
actionBar.setDisplayHomeAsUpEnabled(true);
}
}

Make sure that you have declared the parent activity in the manifest like this...
<activity
android:name="com.myapp.SetPreferenceActivity"
android:parentActivityName="com.myapp.MainActivity"
>
and then make sure to add the case into your onOptionsItemSelected method...
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// Respond to the action bar's Up/Home button
case android.R.id.home:
//Take me back to the main activity
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
if you prefer to have the up button point to a custom activity, you can just use an intent.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// Respond to the action bar's Up/Home button
case android.R.id.home:
Intent changeActivity = new Intent(this,OtherActivity.class);
startActivity(changeActivity);
return true;
}
return super.onOptionsItemSelected(item);
}

The default behaviour of the Back button is that it will get you back to the calling activity. The system maintains a back stack of activities while the user navigates the application. Do you need to override this functionality? Please be more specific.

Solved in this way:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
finish();
}
return true;
}

Up Button in ActionBar with the possibility to move more activities

I'm doing an app for Android. In the DetailActivity, there is the ActionBar with the Up Button. When I press it, it would return in the previous activity. But the DetailActivity can be launched from different activity.

Instead of using NavUtils.navigateUpTo(this, upIntent) , you can just use finish() or onBackPressed(). This would finish the activity, and go back to the previous one. So handling of the Up button being pressed would look like this:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// Respond to the action bar's Up/Home button
case android.R.id.home:
finish();
return true;
}
return super.onOptionsItemSelected(item);

Show a dialog when the actionbar 'up' button is pressed, and prevent activity from finishing

I'm using
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
backPressed();
break;
}
return super.onOptionsItemSelected(item);
}
backPressed() creates a dialog, and should wait for button click. If 'ok' is pressed, finish the activity, else, don't finish the activity.
At the moment the dialog is created, but then the activity finishes and the dialog disappears.
Is it possible to achieve that?

Unless you return true from onOptionsItemSelected(), you're basically telling Android "I didn't handle this, do whatever you are supposed to do with it".
In this case, since you want to intercept the home action, just return true after calling backPressed().
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
backPressed();
return true;
}
return super.onOptionsItemSelected(item);
}