从孩子返回时，家长活动不断重置

Question

When I use an intent to move from parent activity to another, and then use action bar nav to go back to parent, the parent activity has lost all my changes and values (as a user) and is back to default xml display i have for it.

I have these in my Child activity OnCreate:

 ActionBar actionBar = getSupportActionBar();
actionBar.setHomeButtonEnabled(true);
actionBar.setDisplayHomeAsUpEnabled(true);

And labeled my parent activity appropiately:

android:parentActivityName=".MainActivity"

What do I need to make it store or remember those changes when traveling between activities?

Answer 1

There are couple of options to try -

1) start the new activity with startActivityForResult()

2) in the manifest file, set the android:launchMode="singleTop" of the parent activity

Hope it helps

Answer 2

In the Manifest file, you should set android:launchMode like this:

<!-- ACTIVITY -->
        <activity
            android:name=".activities.MainActivity"
            android:configChanges="orientation|screenSize"
            android:launchMode="singleTask"
            android:screenOrientation="portrait"/>

Ps: read Launch Mode on this link: https://inthecheesefactory.com/blog/understand-android-activity-launchmode/en

Answer 3

You might be creating a new instance of your parent when you click the Navigation button. A simple approach is to just finish your activity so whatever activity in the backstack will simply be resumed.

Something like this:

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