java - 尝试使用notifyDataSetChanged更新listView的自定义列表适配器但不起作用

Question

添加新文件时如何正确更新我的 listView 适配器？ listView 由一个数组提供。我读了很多书，尝试了很多东西，但没有任何效果。我错过了什么吗？由于某种原因，notifyDataSetChanged 无法正常工作。

activity.java

创建时:

ListView list2;    
CustomList listAdapter;
String[] ficheros;

final File carpeta = new File("/storage/emulated/0/Android/data/cc.openframeworks.androidMultiOFActivitiesExample/files/xml");


    list2=(ListView)findViewById(R.id.listview);
    list2.setVisibility(GONE);
    list2.setCacheColorHint(Color.TRANSPARENT);

    ficheros = list.toArray(new String[list.size()]);
    List<String> list = new ArrayList<String>();
    listAdapter =  new CustomList(OFActivityA.this, ficheros,fecha);
    list2.setAdapter(listAdapter);
    listarFicherosPorCarpeta(carpeta);

@Override
protected void onResume() {
   super.onResume();


public void listarFicherosPorCarpeta(final File carpeta) {
   for (final File ficheroEntrada: carpeta.listFiles()) {
         if (ficheroEntrada.isDirectory()) {
               listarFicherosPorCarpeta(ficheroEntrada);
              } else {
                 System.out.println(ficheroEntrada.getName());
                 list.add(ficheroEntrada.getName());
              }
            }
      listAdapter.notifyDataSetChanged();
           }

自定义列表.java

public class CustomList extends ArrayAdapter<String>{

    private final Activity context;
    private final String[] ficheros;
    private final String[] fecha;

    public CustomList(Activity context, String[] ficheros, String[] fecha) {
        super(context, R.layout.rowlayout, ficheros);
        this.context = context;
        this.ficheros = ficheros;
        this.fecha = fecha;
    }

    @Override
    public View getView(int position, View view, ViewGroup parent) {
        LayoutInflater inflater = context.getLayoutInflater();
        View rowView= inflater.inflate(R.layout.rowlayout, null, true);
        TextView txtTitle = (TextView) rowView.findViewById(R.id.listtext);
        TextView txtFecha = (TextView) rowView.findViewById(R.id.fechatxt);
        txtTitle.setTextColor(Color.parseColor("#015D99"));
        txtTitle.setHeight(123);
        txtFecha.setText(fecha[position]);
        txtTitle.setText(ficheros[position]);

        return rowView;
    }

Answer 1

如果数据集中的内容发生更改，

notifyDataSetChanged() 将起作用。您在 onResume() 中调用它，它可能会在函数循环完成之前被调用。尝试更改函数调用并在 for 循环完成后添加 notifyDataSetChanged()。

public void listarFicherosPorCarpeta(final File carpeta) {
   for (final File ficheroEntrada: carpeta.listFiles()) {
         if (ficheroEntrada.isDirectory()) {
               listarFicherosPorCarpeta(ficheroEntrada);
              } else {
                 System.out.println(ficheroEntrada.getName());
                 list.add(ficheroEntrada.getName());
         }
   }
   listAdapter.notifyDataSetChanged(); //call it here after you have updated your data.
}