Question

我制作了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
    }

所以当我点击项目时，项目会从列表中删除，但列表不刷新？当我完成的时候（）;然后再次启动活动而不是删除一条线，但我想立即删除..

@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
    }

谢谢！

Answer 1

<强>尝试

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

ListView由适配器支持。你的适配器由String []支持，从这一行：

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

您需要从适配器中删除对象，而不是列表。在你的onListItemClick中执行以下操作：

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

如果要从List对象中删除该项，您可以，但不确定您的用例。也许你想保留它，以便你可以在某个时候恢复ListView。

Answer 3

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

ListActivity Android上的刷新列表

3 个答案: