在ListActivity Android上刷新列表

Question

I made and ListActivity :

public class Remove1 extends ListActivity{

    ArrayList<String> listaE = new ArrayList<String>();
    ArrayList<String> listaL = new ArrayList<String>();
    int resh=0;
    InputStream instream;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        lexo(); //Fill list from file
        String[] mStringArray = new String[listaE.size()];
        mStringArray = listaE.toArray(mStringArray);  //change list to String[] Array
        setListAdapter(new ArrayAdapter<String>(Remove1.this,android.R.layout.simple_list_item_1,mStringArray)); //Fill List
    }

So When I click item, item is removed from list, but the list is not refreshing ? When I finish(); and start activity again than it removes a line,, but I want to be removed instantly..

@Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);
        listaE.remove(position); //Remove Line
        listaL.remove(position); 
        write(); // write to file changes
        lexo(); // read from file changes and fill lists
    }

Thank you !

Answer 1

Try

public class Remove1 extends ListActivity{

    ArrayList<String> listaE = new ArrayList<String>();
    ArrayList<String> listaL = new ArrayList<String>();
    int resh=0;
    InputStream instream;
    ArrayAdapter<String> adapter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        lexo(); //Fill list from file
        String[] mStringArray = new String[listaE.size()];
        mStringArray = listaE.toArray(mStringArray);  //change list to String[] Array
        adapter = new ArrayAdapter<String>(Remove1.this,android.R.layout.simple_list_item_1,mStringArray);
        setListAdapter(adapter); //Fill List
    }

@Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);
        listaE.remove(position); //Remove Line
        listaL.remove(position); 
        write(); // write to file changes
        lexo(); // read from file changes and fill lists

       adapter.notifyDataSetChanged();
    } 

Answer 2

A ListView is backed by an adapter. Your adapter is backed by a String[], from this line:

String[] mStringArray = new String[listaE.size()];

You need to remove the object from your adapter, not your list. In your onListItemClick do this:

ArrayAdapter<String> adapter = (ArrayAdapter<String>) l.getAdapter();
String item = (String) listaE.remove(position);
adapter.remove(item);
adapter.notifyDataSetChanged();

If you want to remove the item from your List object, you can, just not sure of your use case. Perhaps you'd like to keep it so you can restore the ListView at some point.

Answer 3

从mStringArray删除与列表中已删除项目相对应的字符串，并在ArrayAdapter上调用notifyDataSetChanged() （必须先将其存储在某个变量中）。