1. 确认你已经实例化了ArrayAdapter，并将它设置给了ListView。

2. 调用ArrayAdapter的add()方法或addAll()方法添加元素。

示例代码：

ListAdapter.java

public class ListAdapter extends ArrayAdapter { private ArrayList items; public ListAdapter(Context context, ArrayList items){ super(context, R.layout.list_item, items); this.items = items; }

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View view = convertView;
    ViewHolder holder;

    if(view == null){
        LayoutInflater inflater = ((Activity)getContext()).getLayoutInflater();
        view = inflater.inflate(R.layout.list_item, null);

        holder = new ViewHolder();
        holder.text = (TextView)view.findViewById(R.id.item_text);
        view.setTag(holder);
    }
    else{
        holder = (ViewHolder)view.getTag();
    }

    holder.text.setText(items.get(position));

    return view;
}

private static class ViewHolder{
    public TextView text;
}

}

MainActivity.java

public class MainActivity extends AppCompatActivity {

private ArrayList items;
private Button addButton;
private ListView listView;
private ListAdapter listAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    addButton = (Button)findViewById(R.id.add_button);
    listView = (ListView)findViewById(R.id.list_view);
    items = new ArrayList();
    listAdapter = new ListAdapter(this, items);
    listView.setAdapter(listAdapter);

    addButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            addItem();
        }
    });
}

private void addItem(){
    EditText editText = (EditText)findViewById(R.id.edit_text);
    String itemText = editText.getText().toString();
    if(itemText.length() > 0){
        items.add(itemText);
        listAdapter.notifyDataSetChanged();
        editText.setText("");
    }
}

}

这个示例代码演示了如何将元素添加到ListView中，添加到ArrayList中的元素会自动显示到ListView上。如果手动调用了listAdapter的notifyDataSetChanged()方法，则ListView会刷新并显示新添加的元素。