Android使多个微调框膨胀会导致奇怪的选择行为

Question

in the program I inflate several Spinners and add them to a layout. For each spinner I make an individual selection. This works fine if the Activity is created as usual - so every spinner gets his own selection. If the activity is created due to a rotation it will apply the value of the last spinner to all spinner and I watched that a onItemSelectedListener will be called multiple times. I am very desperate since that seems not very logic to me. Here is the code:

SpinnerTesterActivity.xml

public class SpinnerTesterActivity extends Activity {
    public String[] array={"s0","s1","s2","s3","s4","s5","s6","s7","s8","s9"};

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Log.d("SPINNERTESTER", "REPAINT ACTIVITY");
        LinearLayout layout=(LinearLayout)this.findViewById(R.id.parentLayout);

        for (int i = 0 ; i<3; i++){
            LayoutInflater layoutInflater = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            ViewGroup reminderLayout = (ViewGroup) layoutInflater.inflate(R.layout.edit_item, null);
            Spinner spinner = (Spinner) reminderLayout.findViewById(R.id.spinner);
            spinner.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, array));
            spinner.setSelection(i);

            layout.addView(reminderLayout);

        }
    }

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:id="@+id/parentLayout" >
</LinearLayout>

edit_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:paddingBottom="3dip"
    android:paddingTop="3dip" >

    <Spinner
        android:id="@+id/spinner"
        android:layout_width="0px"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:gravity="center" />

</LinearLayout>

Answer 1

I believe the default save and restore functions identify each View by its id, since all of your Spinners have the same id they receive the same data. Simply give the Spinners their own ids, even a generic id like this:

spinner.setId(i);

---

A couple other quick points:

1. Your layout edit_item.xml has a LinearLayout with only one child, this is unnecessary. Simply use the Spinner as the root element:

    <Spinner xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/spinner" android:layout_width="wrap_content" android:layout_height="wrap_content" /> 

2. You are fetching the LayoutInflater on each loop, you only need to do this once.

All together:

    LayoutInflater layoutInflater = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    LinearLayout layout=(LinearLayout)this.findViewById(R.id.parentLayout);

    for (int i = 0 ; i<3; i++){
        Spinner spinner = (Spinner) layoutInflater.inflate(R.layout.spinner, null);
        spinner.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, array));
        spinner.setId(i);
        spinner.setSelection(i);

        layout.addView(spinner);
    }

Hope that helps!