AutoCompleteTextView doesn't update arrayadapter items

问题

The following App flow shows what I expected ("Alfa" in the autocomplete list):

Open App -> click on button -> tap on autocomplete field -> type "al"

But this one fails (and if I type "br", "Bravo" is still in the list):

Open App -> tap on autocomplete field -> type anything and then delete it -> click on button -> tap on autocomplete field -> type "al"

Why the list is not updated in the second sequence?

public class DisplayFragment extends Fragment {

 AutoCompleteTextView autoCTVShop;
 Button buttonSend;

 String[] names= {"Bravo","Charlie","Delta","Foxtrot"};
 ArrayAdapter<String> adapter;

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {            
    return inflater.inflate(R.layout.fragment_display, container, false);
 }

 @Override
 public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    autoCTVShop = (AutoCompleteTextView) getActivity().findViewById(R.id.autoCompleteTextViewShop);
    adapter = new ArrayAdapter<String>(getActivity().getApplicationContext(),
            android.R.layout.simple_list_item_1, names);
    autoCTVShop.setAdapter(adapter);
    buttonSend = (Button) getActivity().findViewById(R.id.buttonSend);
    buttonSend.setOnClickListener(new View.OnClickListener() {  

        @Override
        public void onClick(View v) {
            //The following two lines don't work as I expected
            names[0]="Alfa";
            adapter.notifyDataSetChanged();
        }
    }); 
 }


 @Override
 public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
 }
}

fragment_display.xml:

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

<AutoCompleteTextView
    android:id="@+id/autoCompleteTextViewShop"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:ems="10"
    android:imeOptions="actionNext"
    android:singleLine="true" />

<Button
    android:id="@+id/buttonSend"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:clickable="true"
    android:enabled="true"
    android:text="Button" />

</LinearLayout>

Thanks.

回答1:

Internally the ArrayAdapter uses 2 lists to store and handle the items. Initially your passed in items are stored and handled through a list named mObjects. Any changes to your outside names object would be reflected in the mObjects list as well.

As soon as you start filtering, a second list, named mOriginalValues is created. During the filtering flow, mObjects is going to be used as the "current values" container, while mOriginalValues is used as a "reset to and re-filter" container. Changing the names values will have no influence anymore. You could change the adapter values directly (adapter.insert(...), adapter.remove(...) - it will modify mOriginalValues) or recreate the adapter

回答2:

I am pretty sure it is case sensitive. Try Al... that might be it. Also it could be because you are replacing names. I am not certain but when you pass through names it could be setting it to an instance var that won't update at the same time. so you will need to re-pass through the array.

来源：https://stackoverflow.com/questions/32210404/autocompletetextview-doesnt-update-arrayadapter-items

标签

android

android-arrayadapter

autocompletetextview