ArrayList Adapter (for ListView) only displaying the first added item

Question

Edit3: My own item list layout:

<?xml version="1.0" encoding="utf-8"?>

<TextView xmlns:android="http://schemas.android.com/apk/res/android"
      android:id="@android:id/text1"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceListItemSmall"
      android:gravity="center_vertical"
/>

Edit2: Honestly, I might just make a for-loop that creates buttons for each file. This is way too much of a headache to be worth the time.

Edit: I'd like to emphasize the fact that I've copy+pasted my exact code into a new test app and it works fine. That might give you guys a clue.

After tons of debugging, I've narrowed down a problem. I'm trying to add items (files) to an ArrayList, then put that into an ArrayAdapter, and finally display the items in a ListView. The problem is that only the first added item is being displayed.

Here's how I was trying to do it:

ListView listView = (ListView) view.findViewById(R.id.templateFilesList);

    ArrayList<String> templateList = new ArrayList<>();



    File myDir = getContext().getFilesDir();
    File[] templateFiles = myDir.listFiles();

    int length = templateFiles.length;

    for(int i = 0; i < length; i++){
        templateList.add(templateFiles[i].getName());
    }

    ArrayAdapter arrayAdapter = new ArrayAdapter<>(getContext(), android.R.layout.simple_list_item_1,
            templateList);

    listView.setAdapter(arrayAdapter);

The templateFiles[] array properly gets the 8 files in Internal Storage (confirmed via logcat/debugger), but only the first item is displayed in the ListView. Here's a clearer look at the issue:

// If I replace the for loop with this:

    templateList.add(templateFiles[1].getName());
    templateList.add(templateFiles[0].getName());

Only templateFiles[1] is displayed. Similarly, if I do this:

    templateList.add(templateFiles[0].getName());
    templateList.add(templateFiles[1].getName());

Only templateFiles[0] is displayed. Any ideas on what's going wrong?

Here's my XML:

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.template_housing.MyTemplatesFrag"
    android:orientation="vertical"
    android:gravity="center_horizontal"
    >

<TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/my_templates"
        android:textSize="34sp"
        android:textColor="@color/black"
        android:background="@color/Gold1"
        android:gravity="center_horizontal"
        android:padding="5dp"
        android:layout_marginBottom="10dp"
/>

<ListView
        android:id="@+id/templateFilesList"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
>

</ListView>

Answer 1

If you are updating the content of your adapter you should be calling notifyDataSetChanged() as well to make sure your adapter gets to know that your content did change

Answer 2

I copied your code and ran it in Android Studio. It seems NO problem.

Here is my activity code(same xml code), the only difference is that I use an Activity, you may use a Fragment.

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ListView listView = (ListView) findViewById(R.id.templateFilesList);
    ArrayList<String> templateList = new ArrayList<>();

    File myDir = getFilesDir();
    File[] templateFiles = myDir.listFiles();
    int length = templateFiles.length;

    //case 1: in my project, length is 1, show only one element, see case2.
//        for (int i = 0; i < length; i++) {
//            templateList.add(templateFiles[i].getName());
//        }

    //case 2: try to add simple strings, 
    //because you said put simple strings in the list could cause the problem, too.
    templateList.add("a1");
    templateList.add("a2");
    templateList.add("a3");

    ArrayAdapter arrayAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1,
            templateList);
    listView.setAdapter(arrayAdapter);
}
}

I shared my code on GitHub.I strongly recommend you post your fully code on Github, let's review your code.